Yamaha RZ/Banshee build

[el chupacabra]

Hello, long story short after years of owning RGV250s and having a couple of seizures chasing performance i decided to hack up my frame and fit a set of banshee cases i got from the states knowing that they had more potential for a lightweight race bike. (just for track days and the odd club races)

So at this stage i have everything laid out in the floor to make an engine from almost all new parts. Now i am wondering if anyone has any suggestions as to things i should do to maximize performance without breaking the bank. Heres what i have so far.

cases
4 mil crank with TZ bearing and 115 con-rod
A banshee first gear with rz250 ratios for second - sixth
All new seals and bearings
Heavy duty clutch spring with a new OEM sock clutch and fibers
Aluminium water pump
Cool heads with 18cc domes
Stock cylinders ported to 130/195 ex/trans (these were $85 Chinese jobbies so i could learn how to port without much risk cheetah cubs with domes and pistons looking at $2000 before shipping and duty tax)
Blaster pistons with a 2mm spacer plate
V force 4 Reeds
Zeeltronic ECU (running a Chinese ignition coil at the moment)

So i had a go at making a pipe (the half finished one pictured) but after a bit of reading figured out that the 118mm belly diameter was a bit ambitious so here is my next pipe i am sending off to be laser cut (please if you have any educated suggestions before i send it off)

I am also undecided about carbs. I am looking at Mikunioz and i can get a TM35 flatslide for $250AUD but then i can get a 34mm VM round slide for half the price. Does anyone have any advice on the best size car and which is better round or flat for the price?

Cheers for any help you might be able to provide.

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[husaberg]

cool build subscribed
oko copy PWK are cheap and reasonable quality.
Go for TM over VM they went to flat slaides as they offer bette low and mid range as they have less dead space above the needle.
Neil likely has some left over bypass thermostats that he used to make for TSS.

F5 dave has built up a large RZ mill.

[F5 Dave]

I'd always go for PWK keihin , generally just betterer and easier. I run 35mm on my 496 roadbike. That is conservative for a 500, for a long stroke trackbike 35s should be fine.

Price varies wildly. Of the copies oko is better than other junk, but I've spent a bunch of time trying to sort out other people's ones on fxrs and they are a bit shit.

[el chupacabra]

So out of curiosity, what are the major differences between the Keihin and the Mikuni in your experience? Also do you know what your pipes tuned length and belly diameter are? Not to keen on spending too much on pipes if I can just make them and learn something at the same time.

[F5 Dave]

Every time I've replaced flat slide mikuni with pwk I've gained power and throttle response. Seem to be easier to jet but that said anything will need experimentation
My 350 came with pwk28s and was supposedly dynod at 70hp.

My 500 pipes wont be suitable for your , um like 370cc? Not sure what 4mm does on stock bore. Pi R squared divided by 4, times stroke which is probably 58 now. If you have a flash crank I'd aim at 10,000 rpm peak. My 350 road bike was like 9200, heck so long ago but up 3-400 rpm on stock. Yesh think was 8900 std
Old cranks will surely fail.

I'm assuming you have read Bells book which will give you calculation of length as a starting point. There will be 350 pipe specs on internet somewhere. Norbos site or RZ500 forum do 350 stuff. Or find someone with engmod.

[el chupacabra]

I’ve have bells book and have read most of the ese thread. I kept finding that things from the thread contradicted some of the things in bells book. I even considered just copying the tz750 pipe but thought better of it. I have only been able to find tz250 pipes.

It’s 372cc and the total length of the pipe using the FOS calculator is 945mm from the piston to the stinger. I went for a 33% header 66% diffuser 77% belly. I copied the ratio of lengths of the three diffusers from a nsr300 pipe and changed their angle on an educated guess to move the power to front side of the curve. And just thought I’d be conservative on the diameter with 110mm being the max for a rz. And the fact it has no powers valves.

[F5 Dave]

Oh, right. It's a Banshee. The Bell book is old and of it's time. I forgot about the FOS calculator. - and in last few pages of ESE threadsome chap excel sheeted it so just run it through that.

Pwk28s will be a fine choice and there will be heaps of manifolds to fit 28mm carbs. Mine had first model TZR reedblocks squeezed in but good luck finding those these days.

I've bought pwk28 as kx80 carb on Ebay.



https://www.ebay.com/itm/New-OEM-Kawasaki-Keihin-Carburetor-PWK-KX100-KX85-KX-100-85-2001-2002-2003-2013/223502289345?fits=Model%3AKX80&epid=21003311415&hash=item3409c649c1:g:wYEAAOSw1Udcu8T2

2hundy each and will not give you any grief. Great value. Plenty of info about jetting them on net. You will be tempted by the $50 equivalents . How much is a track day? and how much time do you want to spend pushing the bike back to the pits when the float needle jams closed? Again.

[el chupacabra]

You don’t think there is any need to go bigger than 28mm for a trackday bike? Like they won’t hold back any HP? I’m only looking at genuine carb options at the moment as well although my friend has lent me some knock off 38mm keihins I’m reluctant to try.

[husaberg]

KDX200 ran 35mm PWK
but they will all be fogged out in the needle jet by now
Rob "TZ350" buys these from here only for the ese team
https://www.treatland.tv/OKO-34mm-carburetor-with-metal-float-bowl-p/oko-34mm-carburetor-metal.htm

[F5 Dave]

My 350 reputedly made 70hp with 28mm
No power valves so don't go crazy

It will still out grun a wheezy RGV through sheer capacity.

[el chupacabra]

What was done to your 350 to make 70hp?

All I’m waiting on is the pipes to come from the laser cutting place after Christmas before I start cleaning assembling the engine. Then rebuilding all the Callipers and finding the $$$ for a rear shock. But like all projects it’s already a year over schedule.

[F5 Dave]

A year, pah! Child's play. Mines about 10.

So I bought my 350 as base for my 496. Had Toomey pipes, pwk28s, TZR reedblocks and a fairly typical port.

[el chupacabra]

the new better designed pipes have just showed up. Time to get rolling.
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[F5 Dave]

Coolness.
. . .

[el chupacabra]

Welded all of the cones up today and have taped one set together to see how they fit. The next step is to take the bike to the workshop and weld them up also using the stock RGV rubber exhaust mount.
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[el chupacabra]

Pipes should be mounted by the end of the week

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[el chupacabra]

Managed to get the pipes both finished tonight. Minus the mounts.

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[F5 Dave]

Swift work. Obviously try to replicate pipe mounts that won't crack, like RS125 or dirtbikes. KTM rubber mid mounts are fairly cheap.

[el chupacabra]

I’m going to copy my tyga pipes by double skinning it and then welding on the bracket along the bottom edges inline with the pipe so it doesn’t crack (hopefully).

[el chupacabra]

Progress, I have run out of time to fit the stingers this week, I will check the if fairing clears in the mean time. Otherwise I will just have to hack it up a little.

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[el chupacabra]

Only the belly pan needs some cutting on the left hand side to clear the belly of the exhaust

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[Ian Staples]

Hi . Very nice work ! Here's something you may find interesting'. A friend of mine is into racing quads and has a very hot banshee that I'm pretty sure there's bugger all banshee left in it and he told me the only oil he could use to prevent seizing was Castrol R. I thought it rather fascinating that one of the oldest racing oils could beat the newest. regards Ian

[Bonez]

Hi . Very nice work ! Here's something you may find interesting'. A friend of mine is into racing quads and has a very hot banshee that I'm pretty sure there's bugger all banshee left in it and he told me the only oil he could use to prevent seizing was Castrol R. I thought it rather fascinating that one of the oldest racing oils could beat the newest. regards IanWell according to the burb it is more oilier. I suspect the smell might be a reason as well for using it.

[malcy25]

Hi . Very nice work ! Here's something you may find interesting'. A friend of mine is into racing quads and has a very hot banshee that I'm pretty sure there's bugger all banshee left in it and he told me the only oil he could use to prevent seizing was Castrol R. I thought it rather fascinating that one of the oldest racing oils could beat the newest. regards Ian

R has very good lubricity properties to this day. It just has some down sides that make it a pain in the arse. Serious downsides as compared to modern synthetics. Like it's unwillingness to mix or stay mixed. Piston varnishing etc.

for use in a 4 stroke, it's "shear strength" years ago when I last heard was better than 300V Motul (itself an outstanding oil)

I Have used 8002T Motul religiously since it came out and 4002T before that in all my 2 stroke premix road race applications. 33 years I've been buying it. It has proven to be very good at 30:1 in watercooled and 25:1 in aircooled. I think there are some better oils, but 800 is VERY good. Good enough for my needs .


Plenty good enough for me and 74-78bhp from my 350 Yamaha (TZ) for the last 20 odd years and 130 from it's big brother (real dyno HP, not guesses).

Before that, my brother and I used Castrol R or Shell M at 16:1 or even richer.

As I understand it, where the very best modern oils come into their own on a 2 stroke is very high combustion temperatures. The very best actually get more slippery.....ELF 976 is one of those. They only really come into play if you run into a "problem" which pushes temps through the roof. But you also pay for it. 99% of people are fine with 800! Motul.

You can also get modern synthetic Castor based racing oils from Penrite, from Supercheap!

Don't forget, ask 12 people for their opinion on the best oil and you'll get 15 answers....

[F5 Dave]

You only have to go on organised trail rides to form a pathological dislike of quad riders. Car drivers of the dirt. People build up Banshees from aftermarket kit parts with little respect of their interaction. The 'Best' pipes are bought, then the buy a monster big block. The stinger size(s) are then too small for a near 500 (175 vs 250). Then they go great until they melt a piston. What is the real cause? Must be the oil. Sigh.

Same thing with big bore RGVs, NSRs etc have to watch stinger sizes. Presumably OP has this calculation for his engine.

[malcy25]

You only have to go on organised trail rides to form a pathological dislike of quad riders. Car drivers of the dirt. People build up Banshees from aftermarket kit parts with little respect of their interaction. The 'Best' pipes are bought, then the buy a monster big block. The stinger size(s) are then too small for a near 500 (175 vs 250). Then they go great until they melt a piston. What is the real cause? Must be the oil. Sigh.

Same thing with big bore RGVs, NSRs etc have to watch stinger sizes. Presumably OP has this calculation for his engine.

yep, when I see a holed piston and people are talking oil......RUN!!!

[F5 Dave]

Even just seized there's usually a reason.
Then the Amsoil zealot shows up (slips on Nikes)

[el chupacabra]

Well my stinger size was figured out just using a drawing of a tyga pipe for an nsr300 a friend had sent me. The drawing has the stinger at 25mm. I am adding the stingers before I weld on the tail pipe to the mufflers. These will be turned in a lathe. Then the tail pipe is 26.2 ID and 28.6 OD, this will lead up to the flange for the muffler which has a 26.5mm exit.

I’ve done a lot of reading today and noticed all of the banshee pipes are .905inch (23mm) or 7/8 ID (22.2mm) for their small bore stingers. I’ve also noticed early this 250s stingers between 20-22mm. Even the Aprilia RSA boasting something like 58hp is only 23.3mm (although it has quite efficient cooling of the piston) so for something that I’m hoping will make like 75-80hp (less than 40hp per cylinder) I'm thinking I might have to drop the stinger down to something that works on all those ATVs. 23-23.5mm (knowing that the cooling on the banshee isn’t quite up to par with a GP bike. I’m thinking 25mm would be good if I opted for a set of 421cc cheetah cylinders.

[el chupacabra]

As for oil I haven’t put too much thought into that. My RM250 uses Castrol’s TTS and runs fine with a new piston every second year and the bore looks mint. That’s running 40:1. For this I’m planning to run it on 30:1 all I need to figure out is what oil to use and what’s good value for money because it seems people aren’t too fond of the TTS.

[F5 Dave]

Yeah a mate has an mc28 with tyga kit. Same deal, stingers too small for 150cc. Presumably you mean Sketchy who has done testing on his to increase size. Power output and cc will be different of course.

[el chupacabra]

Yeah, he is who my friend got the drawing to make his pipes from. Would I be limiting the maximum HP by selecting a stinger too big vs risking cooking the engine or having to jet very rich to keep it alive If they are too small. Maybe I shoot in the middle with 24mm. I mean I can always cut them off and try another size.

[husaberg]

Yeah, he is who my friend got the drawing to make his pipes from. Would I be limiting the maximum HP by selecting a stinger too big vs risking cooking the engine or having to jet very rich to keep it alive If they are too small. Maybe I shoot in the middle with 24mm. I mean I can always cut them off and try another size.

If you put nozzles in them, then the stinger size is irreverent as long as it not the limiting factor.

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131099423&highlight=stinger+nozzle#post1131099423

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner/page218?p=1129954861#post1129954861

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1129955411#post1129955411

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130089030#post1130089030

https://www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1130209099&highlight=nozzle#post1130209099

[F5 Dave]

I'd go big and reduce from there, esp if you are sorting out jetting and ideally can run or borrow egt

[el chupacabra]

I was either going to borrow or buy an EGT, probably a digitron or a kosso one. That is a neat idea. I’ll just use that as a solution for trying different stingers seeing as I have a lathe at my disposal. I wonder how much leakage there will be.

Heading into super cheap today to get mx bike oil and fork oil I had a look at the oil selections and then went to the Suzuki shop and saw their motul selection. Seems between $30-45 is what you pay for full synthetic. Unless it’s Castrol which is about $22.

The Penrite castor they had there says it’s fully synthetic and has a low ash formula I’m tossing up the idea of using this as I don’t have power valves to gum and it will be a dedicated track bike. It might give me some fudge factor.

[Kickaha]

it seems people aren’t too fond of the TTS.
Nothing wrong with it, I've used it in various forms for decades, air cooled, water cooled, road bikes, race bikes, Karts, I haven't once had a failure related to it

[F5 Dave]

Caster requires care, bit of acetone to help it mix properly then throw rest out at end of day. I've used Motul 800 in all my race bikes.

I run TTS in my 500 as it's cheap and its supposed to be a road bike, so economy is a consideration but only really dyno hours on it.

A mechanic told me the other day if a road bike was in ,(80s and 90s) and had failed bottom end it would be TTS and quite dry. But mine is premix so I this I'll keep running it.

[el chupacabra]

At least one thing is certain. Just about every bike shop sells motul and no one has said anything bad about it.

I’m curious what the Gp guys were using whether fully synthetic or a castor synthetic blend. Seeing as they get pulled down so often. This is probably a very easy topic to over think. Although I’m wondering how much more life you would get out of a crank bearings and Pistons depending on the oil you use.

Also how the different oils work as the throttle is closed for braking (although I do blip it when braking and downshifting).

I’ll probably be Mixing the Motul at 30:1.

[malcy25]

At least one thing is certain. Just about every bike shop sells motul and no one has said anything bad about it.

I’m curious what the Gp guys were using whether fully synthetic or a castor synthetic blend. Seeing as they get pulled down so often. This is probably a very easy topic to over think. Although I’m wondering how much more life you would get out of a crank bearings and Pistons depending on the oil you use.

Also how the different oils work as the throttle is closed for braking (although I do blip it when braking and downshifting).

I’ll probably be Mixing the Motul at 30:1.

I have been rebuilding my own motors from day one basically. As mentioned have used fully synthetic 400 or 800 2T in that time. One thing about synthetic oil is that is attracted to metal. It sticks on and doesn't drop off. The term is pour point I think. A good friend found he'd broken a head bolt in his TZ and filled the cases with water. 18 months earlier than when he found it.....crank was under water. He pulled the motor apart and the crank was perfect when he washed everything down. Ran for another couple of years of club and other meetings....

In my engines, I usually see that there is oil everywhere it meeds to be a not dry

Great oil IS CHEAP compared to the effect of a shit oil.

Modern bearings and modern oils, I extend my crank life by >50% compared to Yamaha recommendations. 1000km is now a 1000 miles.

The GP teams were in theory using the oil with a base stock of what the oil manufacturer produced and they each tend to stick to one style of base stock for production. Castrol A747 is castor based, Motul is Ester based. You tend not to want to flit between them, one or the other, or if you do change, stay to what you change to.

[F5 Dave]

My race 50 peaked at 13000rpm and revved on say another 1000. Did ALot of race miles on a rebuilt crank, fed rings yearly and the occasional piston 2-3 years. No breakage.
Same crank 10 years before putting engine on the shelf for another brand engine. I'm keen on 800 at 30:1.

[Kickaha]

Castrol A747 is castor based.

Used that in TZ250 @ 33-1, didn't ever have any problems, everything always looked mint when it came apart

[el chupacabra]

Interchangeable exhaust stinger sleeves done. Hopefully I will bend up the stingers tomorrow and make the flanges for the mufflers.

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[malcy25]

Used that in TZ250 @ 33-1, didn't ever have any problems, everything always looked mint when it came apart

Kick, yeah, if I didn't have good access to Motul, without question I'd have been using A747 for the last 3 decades! In my very humble opinion it is in the top 3 or so 2 stroke oils.

A747 was a great step up in usability from straight "R" .

[el chupacabra]

I managed to fit up one of the tail pipes this evening, progress is a little slow.

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[F5 Dave]

I think yer flying along. Erm, that subframe is looking a little German Streetfighter in angle?

[el chupacabra]

It’s a Tyga subframe. It does seem a wee bit tall as I’m on my tip toes vs I’m flat foot on my vj21 with bent knees.

[F5 Dave]

I always like being low as possible but you can change it if it doesn't work, some people like tall bikes.

[el chupacabra]

Bending the 28.6mm OD tube with a 1.2mm wall thickness for the tail pipes is proving to be a bit average for anything other than the most gentle bend. Does anyone have some hot tips for stopping the pipe creasing? Just asking In case someone has some magic advice not found on google.

[husaberg]

Bending the 28.6mm OD tube with a 1.2mm wall thickness for the tail pipes is proving to be a bit average for anything other than the most gentle bend. Does anyone have some hot tips for stopping the pipe creasing? Just asking In case someone has some magic advice not found on google.

Really dry sand packed very tight sealed ends and heated to red hot and plenty of pipe length
I used to be able to use about 25% of what i tried.
its f-ing dangerous to use sand that is not 100% dry.
dry it in the microwave or oven

the other option is to buy bends from a EX shop our one always had plenty.
You can also buy donuts.
They also have mandrel benders

bigger than i use to use though
I have heard of people packing the pipes with resin then using a tube bender but have never tried it.

[el chupacabra]

I might have to give the sand a try then. Can it be done cold with the ends sealed?

[husaberg]

I might have to give the sand a try then. Can it be done cold with the ends sealed?

Not unless you are blessed with herculean strength or have a tube bender, it needs the heat to avoid the kinks and to control the bending and when it starts and finishes anyway by hand.
but it has to be 100% dry unless you wish to get a potential steam-bath with superheated water under pressure.
Also SS as far as i know work hardens. Doesnt it?

[el chupacabra]

Yeah, I’m pretty sure SS does harden. I do have a hydraulic bender. That’s why I was wondering about doing it cold but I have solved the problem this evening. I cut the chamber up and rotated the end of the baffle so the curve could be more gentle and then just did a very minor curve with the bender.

[el chupacabra]

Got the other tail pipe mounted today.
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[el chupacabra]

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Finished off the hangers for the mufflers today. 4.5mmx30mm aluminium.

[F5 Dave]

RS125 ones never break, but they have no welds. Maybe black them out a bit?

[el chupacabra]

Yeah, I am a little worried they could break. But I’ll see how they fare seeing as I’ve got 2m of aluminium left to make some more without welds maybe.

I’ve just welded some flat to drill and tap onto the cradle so I can attach the lower radiator mounts, I might do the same for the lower fairing mounts or use some sort of clamp.

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[husaberg]

I see what Dave meant those exhaust brackets remeind me of the RS125 and the MV
Personally, i think you could mill the entire center section out, without losing any strength. If you look at the Beart Norton's brake anchor, you will see what i mean.
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[el chupacabra]

When I’ve found a good stinger insert diameter for the removable tail pipes and weld the joint they could be a bit lighter duty. But they are also stopping the exhausts rolling inwards into the swing arm. Or maybe I am just over engineering it a bit, looking at that rear brake anchor.

[el chupacabra]

Slowly getting the ball rolling again. Just waiting on a bolt kit out of the states. I’ve cleaned the cases up. I also had to do a small repair around one of the cylinder studs. 346215

[el chupacabra]

Finally I’ve made some more headway and almost fully assembled the engine. Things left to do are:
-get some 34mm carbs (looking at mikuni oz 34mm round slides)
-drill and tap a plate for the intake rubbers to bolt onto which will fit on the cylinders
-make a plug for the kickstart hole and seal it in there.
-rebuild the brake calipers
-wire up the zeeltronic
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[F5 Dave]

Cool. Not to give you more tasks but stiffer clutch springs are probably in your future. Before you put it back in the the frame you could cut and extend the clutch arm 1cm for more leverage. Still get reasonable straight pull. Not sure if I reangled the holder a little. Don't think I needed to.

You can also add another plate which gives more area. Need to skim basket, thrust plate and possibly washer behind to give enough throw. Actually I think the longer arm helps here.

FZR plates are wider, or smaller internal diameter for a bit more area if you don't run rubber rings which you wouldn't.y

[el chupacabra]

The clutch springs are ‘heavy duty’. Later on I want to get some straight cut gears and a better clutch basket because I’ve heard the stock ones can explode.

[F5 Dave]

Probably as they flog out and get loose rivets.

[el chupacabra]

Today all the engine bolts were torqued up. I then mounted the engine and the exhausts.
The only thing needed to start it is a chain and pair of carbs. Still not sure about going for a 35mm flat slide or 32mm round slide. $250 vs $150 ea.
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[husaberg]

Today all the engine bolts were torqued up. I then mounted the engine and the exhausts.
The only thing needed to start it is a chain and pair of carbs. Still not sure about going for a 35mm flat slide or 32mm round slide. $250 vs $150 ea.
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The whole idea of the flat slides was better response.

[F5 Dave]

2hundy difference. How much did you spend last time out in the Razz?

Oh, right. Palmy. $82 and went home early.


So, ahh, ready for Boxing day?

[el chupacabra]

If it’s taken 3 years to get this far I doubt it’ll be ready haha. It’s just a summer trackday bike. . . Keeping it fun and not too expensive that’s why I might save $200 on carbs and get the cheapest Nitron. The 600 put me off racing on the track with the entry fees and tyre bills and getting up early and rushing around.
Now I just ride my mx bikes as there are 3 tracks 20 mins from home and it’s only $20 to go in your own time any day of the week.

I’m also doing a cnc conversion on a Mill concurrently so I can machine up fork clamps and rear sets for it. So that’ll chew up a little bit of time too once the bits arrive.

[husaberg]

he used to do bigger ones
http://www.motorbikeparts.co.nz/index.php?route=product/product&product_id=85

[F5 Dave]

That always makes me larf

"GENUINE OKO CARBURETOR

[husaberg]

That always makes me larf

"GENUINE OKO CARBURETOR

I know.... he's even copied that blurb off the net as well.
But some "the real deal oko" are pretty decent bits of kit, they seem to be better made than the factory issued Keihin especially the carb body materials.
TZ has used plenty.

[el chupacabra]

Looks like a 30mm OKO could be the ticket can it be set up easily on a two stroke?
Mikuni oz sell a 35mm TM flat slide and a jet kit for a TZ750 that might work or a 32mm rounds slide and a jet kit for a RD350LC or a 34mm round slide and a jet kit for a 1972 TZ350. I just don’t want to go too wrong and buy something that is a pig to jet.

[husaberg]

Paging ROB....

.

Not sure about the other carb's but I know, because of the material used in the casting the genuine OKO from Taiwan, it machines very nicely when you want to make a super trick 30+hp class legal carb that makes a mockery of the 24mm restriction rule, try that with your old pot metal beauty's but shoosh ... :psst: ...you didn't hear it from me ......:niceone: ... :laugh:


if the Kiwi crowd ant help you the aussie option is here
http://oko-australia.com.au/motorcross-enduro-trail/

Keihins on the whole are pretty forgiving to jet but the Mikunis offer an option of a replaceable Jet needle.
i have heard pretty good things re the Tawanese okos's.
One other option is the carbs off a NSR or RGV liely spendy now and less jetting potential.

[F5 Dave]

Having fucked around with several okos trying to get them to behave, I'm glad I bought actual PWKs.

[el chupacabra]

I sold the RGV 34mm carbs I had because it didn’t want to piss around with power jets and the solenoids. I’ll take a look at the Aussie site.

[F5 Dave]

Back to page 1. Hmm, so this is going to be 370ish cc. A pair of 28mm PWK will be ideal and fine for 70hp. Search kx80 carbs new are quite cheap.

[el chupacabra]

So I’ve decided on the OKO carb, I can get a 28mm with a power jet and a 30mm without a power jet, is the power jet a deal breaker or harder to set up?

[F5 Dave]

In theory should provide better accoss the range but I've blocked them or used them depending upon what worked best for the bike.

Spend a bunch of time making sure the float jet works reliably. I'd swap for keihin parts personally. Have to turn carb upside down to remove bowl, as also on PWK, as they are a copy, but also check float doesnt rub. Might need manipulation.

[el chupacabra]

I am definitely going to need to do something about the clutch arm, it is very stiff with the heavy duty springs.
I also mounted the RD350LC stator. I had to drill and slot two of the holes to get it to fit on the banshee cases. I used a dial gauge to set the static advance to 25 degrees.
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[F5 Dave]

If it's not a big hp engine you can get away with every 2nd spring heavy and alternate std springs. Mine is grazing 100hp so I have extra plate conversion and all stiff but longer arm helps.

[el chupacabra]

I was thinking that, I’ll see what some springs will set me back.

[F5 Dave]

If I remember I'll go have a look. Cant remember what I have but have come into several sets from various kits.

Longer arm is worth it anyway and virtually free.

[el chupacabra]

Carbs are here and they fit . . . Just. I might make a small spacer up to help them clear everything. Jetting wise they come with a JJH Needle, 112MJ and a 32 Pilot the power jet doesn’t seem to have a size on it. But I’m hoping I only need to change the main jet to sort out any tuning.
It seems the pilots are usually in the 45-55 range on banshees with the pwk and the mains in the 145-155 range without power jets.
If the power jet is around a 30 hopefully the mains are roughly the right size to at least start mucking around with the bike.
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[F5 Dave]

Sorry had a few. I've just popped down
To the garage. Hope you understand the wife is ready to go so time is limited. Found 3 heavy duty springs at 44mm long. Yours if you want them.

Busy making irrigation holes.

[el chupacabra]

Thank you. you wouldn’t by chance have standard clutch springs? As I already have heavy duty ones and no standard ones?

[F5 Dave]

Ahh yes those too. Pm me your address and when I can get past a post office ill send them.

[el chupacabra]

I’ve made some progress over the last week:
-fitted radiator hoses
-fitted the new jets 55 pilot and 120 main, the power jet is 27 or something like that
-fitted the new reeds and manufactured spacers so the carbs don’t foul on the clutch cable
-wired in a plug for the zeeltronic
-started making a map based off the 31k stock map
-ordered the braided brake lines
-installed the clutch springs, the pull is still quite heavy.
-manufactured reducers for inside the tailpipe (24.5mm)

I will be able to at least start the bike soon which will be exciting. I’m also waiting on some gauges and valves from China to put together some leak down testing equipment before doing any riding of the bike.

Now I need to:
-install the brake lines and bleed the brakes
-shorten the throttle cable and carb springs (the springs are too stiff and the cables are far too long)
-fill with coolant
-sort gear shift rod
-order quickshifter sensor (once it’s running)
-order rear shock (later on)
-fit fairing
-shorten clutch cable (from a banshee and about 3km too long)

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[F5 Dave]

You can make the clutch lever arm on the engine about 8-10mm longer without screwing up the cable direction too much. This helps and it's not very visible, cut, extend, weld. I might've made the cable holder a bit more angled with a grinder, can't remember.

[el chupacabra]

I’ll get it running then maybe give that clutch extension a go.
Today I made the pull/pushrod for the gear shifter and tapped the head 1/8npt for the rgv temp sensor. 348975348976
Now I just need to move the zeeltronic as I don’t like it’s proximity to the spark plugs and the ignition coil. (I’m not sure whether it will effect anything).

[F5 Dave]

Totally it shouldn't be near. Use resistor caps and resistor plugs. Keep power feed and pulsar coil wires away from ignition coil wires.

[el chupacabra]

Today I made a leak down tester. My valves and gauges showed up in under a week from China via AliExpress. Tonight I did a leak down test and found a leak on the RHS cylinder transfers and one from the reed block.
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[el chupacabra]

One step forward and three back . . .
The repaired cylinder stud happened to crack its weld in the HAZ, my stupid fault for using the wrong filler in the first place.
Yesterday, I took the engine out and stripped it down. Today I repaired the broken bit of case with 4043 filler after grinding out a decent chunk of the dirty material. Then used an m8x1.25 recoil in the hole with a new stud. Now it’s all assembled for a leak down test and happens to leak from 6.5-4.75 PSI over 30 mins. The leak is from the LH cylinder LH transfer port. Too much for today to pull it apart again.
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I also extended the clutch arm about 10mm.

[F5 Dave]

Probably won't leak when it's hot. That's a tiny leak.

[el chupacabra]

The leak seems even smaller today. .75 over 30 mins. Looks like I’ll just chuck it back in the bike

[el chupacabra]

So now I am having some trouble getting a spark with the zeeltronic. Any help would be appreciated.
I have it wired up as shown in this diagram. All of the settings are set as per the zeeltronic manual.
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The resistance on the pick up is 87
The red-brown wire measures 250
Also the wires have continuity to the CDI
I have been spinning the bike over with a drill and the plugs out.

I have temporarily fitted the Chinese banshee stator and rotor and the Chinese CDI and used the same earth and coil wires and this is providing perfect spark.
Obviously this won’t allow me to program a curve or run a quickshifter or use the Aprilia dash which is the end goal.

Maybe someone has a stator kicking around I can test or offer some insight into something I may have overlooked.
Cheers

[F5 Dave]

So starting at the start. Tell us about your battery.

[el chupacabra]

I’m just running the rgv battery, it’s showing 12.4v. I’m not running the charging system, just seeing if it’ll spark. Running the red wire to the positive and the - terminal to the chassis which has continuity to the CDIs black wires. I’ll try it again tomorrow and take some pictures of the set up.

[F5 Dave]

As you spin it over check voltage does fall to like 10V or you won't get joy.

Does the Zeel have a test spark feature like the ignitech?
Disconnect kill and quickshifter to be sure.

So where is the earth for the unit? Via the stator? Black wire yeah. Measure that is earth.

Seems odd to me that the stator coils are attached on a DCpowered cdi. Check the pickup coil hasn't been knocked too far away from the magnet of the stator.

Edit, if you tend toward colour blind like me, I'd double check any red green or brown wires are in fact correct.

[el chupacabra]

Voltage stays at 12.2 v when spinning.
The red and brown wire when tested for AC voltage only crank out about 4-4.5 V
I disconnected the kill switch and to make sure it wasn’t faulty.

The set up is a bit of a mess but it’s only temporary.
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[F5 Dave]

Running out of ideas. Remove the plugs from reedblocks so it turns over faster? Try a faster drill?

Check at the cdi red and black that you have 12v.

[el chupacabra]

I ended up selling the zeeltronic and bought another one to suit the banshee rotor. Unfortunately I broke my wrist on the mx bike and didn’t do anything for a few of months. I finally pulled finger this weekend and got the brakes bled and the bike started. It started first pop but won’t idle without the choke on. The next step is to wind all the air screws in as they were 1-1/2 turns out, see if it idles and if not just throw bigger pilot jets at it until it can idle. Currently the bike is running #50 (might be #52, I can’t exactly remember) for the pilot jets.

[F5 Dave]

So presumably you set the idle screws up a bit but no improvement.

I'd be interested in the needle at its closed position. 50 is a reasonable size pilot. It might not be lean despite choke helping. If the needle diameter is too small it could be pulling through big wet drops of gas at idle when ideally the mix is coming through the pilot cct only.

The choke is like a mini carburettor drawing its own air and gas. It might be it is delivering a better mixture of atomised burnable fuel/air.

[el chupacabra]

When I apply more than 1/4 throttle it just bogs (with the choke on). I could lift the needle too just to see if that helps me to get it running without the choke.

[F5 Dave]

Try both ways, it could be waay too rich. Lean will let you slowly eek your way up revs. Rich will just bwoooorh.

[el chupacabra]

It’s a shame I couldn’t upload a video. The bike sounds so good now. So I dropped the needle one clip seeing if that would fix it and nothing changed. Then I had a moment of clarity thinking about how my first timing mark on the zeel map was at 2000rpm. . . And the curve before that mark on the graph shows a straight line but it doesn’t work like this in reality. So I added an extra point on the graph and set it to 17.5 degrees @500 rpm then left the rest of the graph the same and now it revs so clean and runs flawlessly.

I’ll have to lift the needle up again just to make sure it’s safe.
Work out a main jet size till I can get it on the dyno
Then shorten the throttle and clutch cables.
Bleed the rear brake.
Mount the fairing.
Then it’s all finished.

[F5 Dave]

Sweet. Good thinking,

[el chupacabra]

Yesterday I managed to make some little brackets to mount the dash and fairing. It looks like I’ll need to cut more off the belly pan to make it clear properly. I’m also waiting on my air filters to show up before I have a short test ride down the street. 349531349532349533349534349535349536

[F5 Dave]

Looks good. Should be fun..

[el chupacabra]

All the wiring is sorted and the Dash works a treat. I’ve only had it up and down the road once, it does some vicious wheelies in first and second gear. Next step is a dyno tune, I’m thinking about going to Suzuki whanganui for this does anyone know anywhere else local to palmy that might be good?

I’ve also used my new Chinese CNC mill to machine up some new rear sets, I’ve still got to do the RH side and the brake/gear shift levers. Maybe I’ll do a top triple clamp next. 350082

[F5 Dave]

I'm going to say, rather rudely. Uh duh!

Call, Pete Sales at Total. I'm assuming that he still has Chris's dyno. Clever guy. Will charge real money. Will be worth it.

[el chupacabra]

So I had this out on track last weekend (back track at manfield) for a shakedown, just jetting down from a safe size. Handling wise I had to take it easy as the bike has a 10 year old tyre on the front but that wasn’t the point of the test.

Now before I chop the pipes and try tuck them under the bike a bit more as I’m worried about ground clearance, can I just flatten part of the belly or will that completely kill the hp?

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[F5 Dave]

Belly is safest place to do it, yamaha have resorted to this on occasion. Clearance more important that power. . Did I say that?

Make sure you calculate your spring rate and do sag. No point blowing through stroke to dragon ground or bump