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FROSTY
29th July 2004, 16:48
After my last outing at Pukie it seemed Mella yella had got a tadd sick.
Before stripping him down for a rebuild I thought I'd better do a baseline run to see just how bad he is.
After 2 runs on a local dyno I thought the hp test was for someone elses bike. 41 then 42 hp seems a tadd low.
Alex did a compression test for me.
In theory he shouldn't be running it seems. Worst compression is in number 2 at a big 50psi compression.
The others are better but right at the bottom end of the range for a bike to run on.
It seems one of my oil rings has sucked the kumera as well as 3-yes 3 valves bent
Origonally I planned on boring him out to 420cc but I figure now that just a rebore to max oversize a valve grind and replacing the bent valves will be enough to freshen him up.
I still need to sort out the rear shock but It might be a case of borrow the olins out of my zxr750

vifferman
29th July 2004, 16:53
It seems one of my oil rings has sucked the kumera as well as 3-yes 3 valves bent How do valves get bent? Over-revving?
BTW - It's a bit of a worry you calling your bike "him" :Pokey:

White trash
29th July 2004, 16:58
ZXR400s, although beeing the best of the little un's, have a habit of tightening their valve clearances very quickly when continually thrashed.

If you're not on top of it, the valves are not permitted to close properly and a bit of a rev and WALLOP!

Aparently

FROSTY
29th July 2004, 17:00
Yea my foot slipped off the gearchange as I was accelerating from castrol in the pissing rain.
Yea funny innit but mella yella is definitely a bloke -dunno why but he has a bloke personality.

FROSTY
29th July 2004, 17:02
ZXR400s, although beeing the best of the little un's, have a habit of tightening their valve clearances very quickly when continually thrashed.

If you're not on top of it, the valves are not permitted to close properly and a bit of a rev and WALLOP!

Aparently
Thanks WT
I needed reminding I f#$#d up -- :bash:
actually it was more like a bloody gigantic overrrev
still I was gonna pull the head off anyways

Hoon
29th July 2004, 18:41
I wouldn't worry about the rebore yet, just go for new rings, valve grind and 3 valves to get the engine sorted properly then go for the big bore once everything is sweet - will only cost you an extra head gasket and set of rings, otherwise you could end up with a big bored lemon.

We did a top end refresh on my ZXR (valve grind, clearances, and polish up) and now I get 190-210psi on all cylinders. I found a lot of valves were tight and pitted with heaps of carbon on the seats - over 1/2 of them weren't closing properly. You might want to check your valve guides too as mine were worn but not yet ready for the bin.

Also did you get your carbs sorted? Mine have been stripped/cleaned/checked and are all sweet so if you still want to borrow a set for comparison I'm sure we can work something out....... :)

Ohh and make sure nothing is missing from the airbox. I thought I'd do a little optimizing and left off a little snout but it made my bike run like a sack of shit.

Milky
29th July 2004, 22:49
Any idea on the cost of this job? would be interesting to find out for my purposes...

also, on compression testing, it is reasonably easy when the spark plugs are near the surface of the motor... With these ones being stuck so damn far inside, what can you use to check compression by yourself? Would a big long tube do the job? I guess not, unless it is solid pipe. My only experience with compression testing is using the dial gauges that go directly into the plug holes themselves...

Milky
29th July 2004, 22:54
We did a top end refresh on my ZXR (valve grind, clearances, and polish up) and now I get 190-210psi on all cylinders. I found a lot of valves were tight and pitted with heaps of carbon on the seats
Did you do the grind yourself or get a shop to do the dirty work for you? I *might* have a go at it someday after uni has finished if the whole job is cheap enough...

Kwaka-Kid
30th July 2004, 02:21
Milky mate whip em on round here! Got all the valve grinding tools and im sure dad will give you a hand. Been considering doing mine too... but the head is so sealed etc it seems a waste to break it :S hmm.. maybe if i run into a nother engine

Hoon
30th July 2004, 10:44
Did you do the grind yourself or get a shop to do the dirty work for you? I *might* have a go at it someday after uni has finished if the whole job is cheap enough...

Nope did it myself under the close eye of my mechanic. Its a long and tedious job and would prob cost you close to $2K if you got a shop to do it because 95% of it is labour. Only cost me $70 for a new head gasket but I was able to reuse all my parts. Took me close to 2 weeks (of evening work) to get it done so not really something that can be accomplished in a Sat aftn.

FROSTY
30th July 2004, 11:34
Hoon--I hear what you're saying.Its become bloody clear though that a lot of my "carburation" problems were actually valve gear related.
You could as easily have been describing my engine When talking about yours. with the rust etc.
Im doing the job "properly'-Ie strip. down to crank so the motor will be fresh.
If I still have problems then i'll be looking further afeild.
One problem is a funny foam filter that is affecting how she runs.

Milky
30th July 2004, 22:06
Milky mate whip em on round here! Got all the valve grinding tools and im sure dad will give you a hand. Been considering doing mine too... but the head is so sealed etc it seems a waste to break it :S hmm.. maybe if i run into a nother engineDitto here... got the tools, and a dad, and considering doing mine in the distant future, so maybe you would want to whip round here :msn-wink:


Nope did it myself under the close eye of my mechanic. Its a long and tedious job and would prob cost you close to $2K if you got a shop to do it because 95% of it is labour. Only cost me $70 for a new head gasket but I was able to reuse all my parts. Took me close to 2 weeks (of evening work) to get it done so not really something that can be accomplished in a Sat aftn.
I have done the valves on the R65 and on a CB250RS, so i would like to think there was nothing stopping me on this bike... I was never considering going to a shop to do it - money grabbing, pocket lining, 200% markup, couldnt care less about the customer b*&%^$~#s :calm:

Kwaka-Kid
31st July 2004, 07:58
haha nice one milky!
Sweet dude! And nah i seen what a sack of spuds that 250 was compared to mine with my old mans valve grinding and engine rebuild /port skim the lot... and guess whos turned out betteR? :P HAHA! Didnt yours end up using all the left over slow bits mine didnt need? ;) hhahaha! all good bro, yeh itd be interesting to see other ppls ways, how many angles do you guys aim for on a valve grind? i think stock is 2, race is usually 3 but i heard a rumour of 5's! s'all about getting the most flush wearing surface to seal up right?

FROSTY
31st July 2004, 10:28
haha nice one milky!
Sweet dude! And nah i seen what a sack of spuds that 250 was compared to mine with my old mans valve grinding and engine rebuild /port skim the lot... and guess whos turned out betteR? :P HAHA! Didnt yours end up using all the left over slow bits mine didnt need? ;) hhahaha! all good bro, yeh itd be interesting to see other ppls ways, how many angles do you guys aim for on a valve grind? i think stock is 2, race is usually 3 but i heard a rumour of 5's! s'all about getting the most flush wearing surface to seal up right?
Its all in the lapping I think.A 3 angle cut is fine But when its done the lapping in to get a perfect seal in my opinion is more important.
Concept I've been playing with here guys.A valve head is a highly polished surface made none the less of steel. No matter how good a grind we do on a race bike it spends an awful lot of time sitting not running. Im Aucklands damp enviroment could it be we are getting rust on our valve heads?

FROSTY
2nd August 2004, 21:35
I just had the parts arrive for mella yella.
Head gasket $50
Base gasket$40
Valves $30 each -x4
pistons $120 each X4
Rings $60 per set x4
now I guess its time to poke a boring bar down the holes and wear out the fingers with the lapping paste.

Kwaka-Kid
2nd August 2004, 21:42
ohhh man OUCH! shit me if i do my engine i couldnt afford to get it back again!
i remember my CB250RS piston was like $50 inc rings!

FROSTY
5th August 2004, 23:34
yea -painfull hu -sheesh

FROSTY
19th August 2004, 10:21
wel finally I have some action. The new valves have their seats cut, Pistons and rings are in and going up n down.8 valves of 16 are fitted the other 8 are waiting for the valve guide seals to arrive from japan.-for some reason kawasaki only kept 8 in stock at any one time. Mind you at $16.00 each I guess I can understand why.

aff-man
19th August 2004, 10:43
50psi :eek: :eek: . I had 140 when i did the test. By the way if you had all the parts . How long did it take to do all the work??

Paul in NZ
19th August 2004, 21:59
Holy Crappola

Dude... Buy an old Guzzi or Triumph... Those parts prices are EVIL!!

Cheers

FROSTY
19th August 2004, 22:01
50psi :eek: :eek: . I had 140 when i did the test. By the way if you had all the parts . How long did it take to do all the work??
Ill let ya know when I get it finished

gav
24th August 2004, 16:27
So, finished yet?

FROSTY
24th August 2004, 21:14
still waiting for the valve guide seals to turn up. No point in puttin the thing together then takin it appart again

FROSTY
7th September 2004, 20:53
now i'm in a total panic. -some clumsy clod-um er -moi -broke a compression ring on the zxr -big panic--and praying I can get a new ring set in time
the heads all back together butall off again :doh: :doh:

Kwaka-Kid
7th September 2004, 23:56
bugger dude! howd u manage that >? forceing on too much?

badlieutenant
8th September 2004, 00:15
I still need to sort out the rear shock but It might be a case of borrow the olins out of my zxr750
I might know a guy who can rebuild/fix ur shock. PM if your interested and ill get the contact number, I would name him here but I like been able to take my shock to him and dont want every1 too :D but he does an awesome job. My original shock has been rebuilt by him and its better than it was new. Even put a valve in so that I could re-gas if i wanted. Alot of people here probably already know who im talking about. I dont know what people charge for a rebuild but mine was 215.00 and soooo worth it. bike fells so much more stable and goes round corners like its on rails.

FROSTY
8th September 2004, 00:58
bad-if ive got the time the shock wont be a problem--um ohlins.

F5 Dave
8th September 2004, 09:48
Maybe I should have popped in earlier, but apparently the go &/or if you have further problems is to use FZR valves in the ZXR, else replace the ZXR ones regularlyish.

Hoon
8th September 2004, 10:28
bad-if ive got the time the shock wont be a problem--um ohlins.

The shock should fit straight in but the spring might be too stiff for the 400 as the 750 is like 40kgs heavier. It might be fine tho... you'd really want to test it first before rolling up to race day tho!

Ohh and its not that quick to do either....took me a whole evening to swap my rear shock!!!

Kwaka-Kid
8th September 2004, 11:33
yeh tell me about it, just spent since 7:30am installing a new Half system + muffler for my racebike... had to take the shock out and front radiators off (well, swinging) and what a friggin mission! again...

And whats stupid is i dont have time to do the same to my street bike as its got the best shock - and my racebike despite having halfway been there has to stay with the shit shock (6 preload settings, no remote res, and its pogo like damping).

So close... And more bad news? i just realised the system i got was a bloody standerd half system with a hacksawed off muffler and aftermarket/homemade muffler put on... ohh damnit!.. worse again? my last system was from the later model NC35 standerd system which gives better midrange!!!

SO WHAT THE HELL AM I DOING?!
man this is so damn infuriating.

Trial and Error is my way of life.

F5 Dave
8th September 2004, 11:45
True racing machines are so much easier. Getting the shock out of the 750 put me off for so long. The GasGas on the other hand looked just as hard then I realised you just unbolt the rear subframe mounts (just to bottom ones if you are lazy) , loosen the carb connection & rotate the back end out of the way exposing the shock.

Ahh bliss!

Blakamin
8th September 2004, 11:49
yeh tell me about it, just spent since 7:30am installing a new Half system + muffler for my racebike... had to take the shock out and front radiators off (well, swinging) and what a friggin mission! again...

And whats stupid is i dont have time to do the same to my street bike as its got the best shock - and my racebike despite having halfway been there has to stay with the shit shock (6 preload settings, no remote res, and its pogo like damping).

So close... And more bad news? i just realised the system i got was a bloody standerd half system with a hacksawed off muffler and aftermarket/homemade muffler put on... ohh damnit!.. worse again? my last system was from the later model NC35 standerd system which gives better midrange!!!

SO WHAT THE HELL AM I DOING?!
man this is so damn infuriating.

Trial and Error is my way of life.


Are you going to put the old system back on?

how come you didn't notice till now???

Kwaka-Kid
8th September 2004, 12:41
i did actually... but like i said im all about trial and error, i have only tried the NC35 system on my race vfr, and the NC35 system with my chop and modification and home made can, and ive tried the NC30 system on street vfr, and chopped version iwth anohter made can...
so now i guess time to try NC30 system on my racebike, with a different again muffler/dimensions. maybe the dude in aussie was into something? doubt it but still.. apparently the NC35 system just gives a slightly better midrange with no difference top end between the 2. and also the NC30 system im putting on gives slightly more gorund clearance... last round at taupo i put it down on the left and side and hooked the exhaust pipe where its under/on the left side of the bike! lifted what weight was left on the rear end and sent me rear wheel drifting. lucky nothing happend it just came back together as i stood it upright a little, but i dont want to do that too often and it nearly put a hole thru the pipe.

Blakamin
8th September 2004, 12:51
Lets hope you find a combination that works!... glad I've only got the one set! just taking my pipes off drives me nuts!

Jay widda 150
15th September 2004, 15:28
anyone want a blowen rg150 engine to rebuild only $5.

F5 Dave
15th September 2004, 15:30
Let me guess, dropped powervalve. Oh well roll it up the road to Buckets. :crybaby:

FROSTY
16th September 2004, 08:19
to round up this thread I got mella yella finished at the pits at pukekohe.
The motor is now run in and seems to be making good power.
With all the outwork needed and a fairly decent list of parts I think the total is going to come in at about $1500. Sounds a lot but I think we have built a strong reliable motor .
Now I need to focus on my ground clearance and suspension.

That Guy
17th September 2004, 11:32
Phewie - just reading about all this valve graind work and shims and dollars and stuff......maybe my ol'd 2 smoker ain't so bad!

gav
17th September 2004, 14:04
So are you going to dyno it, Frosty?

FROSTY
18th September 2004, 16:49
So are you going to dyno it, Frosty?
I'll sort out the other stuff first. It seems to be running well so I wont muck around with it.I'll get the next round sorted out

FROSTY
14th November 2004, 12:38
After my piss poor showing at Taupo I had to do some serious reevaluation
I need to work on my riding and get more track time but If I wanna compete with the SV650's on an even playing feild then I need to find a fair bit more HP and loose weight.
Yep I'm getting serious now.
The first and most odvious job is to measure fuel consumption. Up till now I've been keeping the tank fairly fullish which means lugging around 20 odd litres of gas and all the weight that entailds. I'll be running a much lighter fuel load.
The flywheel has now had the big chop which hopefully will mean she will get up the revs easily off the line.
Ive been running an O ring chain but thats getting the bin treatment and a lighter chain is going on.
The rear subframe is getting chopped off just behind the seat -I wass going to make a new subframe up but the ally is pretty light weight.
The wiring loom is getting the big strip down treatment and all onnnecasary wires are getting the chop. Makes fixing it easier too
I've ordered the 444kit from the UK through Gary at GP spares--top bloke that. Ill get the spare barrells bored out and keep the standards Just in case
Ive got the Olins rear shock on its way th Hawera Motorcycles to be set up for the 400
Gary Has a Dynajet kit for me so I have adjustable needles to suit different tracks
The CDI box is going in the bin and being replaced with a remappable version from ER and D -With carefull remapping im asured that rather than 4 power spikes like it is now I should get a smooth lineer (sp) power delivery.
Im going to stick with the dunlops because so far I have only had one scare on em -and that was scrubbing the first set in.
Ill be plucking the ignition switch out and and extra seals on wheel bearings etc. The aim is to get a 15% power increase that is usable which should get the power within reach of the SV650's
Im hoping that the next time me and SVS pull onto the straight he wont just grunt his bike away into the distance.

Kwaka-Kid
14th November 2004, 14:36
:o

SERIOUS!

sheesh, Frosty dude give me some of your lotto winnings! Your bike will be god, nice plans though dude if i had the money available for spending on the beast id be doin all that too, what about some nice big flat slide pumper mechanical carbs on her? :D

FROSTY
14th November 2004, 15:53
Was going down the flat slide track but Ill need some serious track time in order to jet em right for the zxr-all the other work is gonna be -bolt it on and go.
KK I guess its all relative--I did think of selling mella yella and buying a sv but like MY finished all up including the cost of the bike will be less than 6k whereas a SV will cost me 11 k then it still needs suspension work-$1500 then a pipe etc--Mella yella looks to be the cheapest option

Redstar
14th November 2004, 15:59
After my last outing at Pukie it seemed Mella yella had got a tadd sick.
Before stripping him down for a rebuild I thought I'd better do a baseline run to see just how bad he is.
After 2 runs on a local dyno I thought the hp test was for someone elses bike. 41 then 42 hp seems a tadd low.
Alex did a compression test for me.
In theory he shouldn't be running it seems. Worst compression is in number 2 at a big 50psi compression.
The others are better but right at the bottom end of the range for a bike to run on.
It seems one of my oil rings has sucked the kumera as well as 3-yes 3 valves bent
Origonally I planned on boring him out to 420cc but I figure now that just a rebore to max oversize a valve grind and replacing the bent valves will be enough to freshen him up.
I still need to sort out the rear shock but It might be a case of borrow the olins out of my zxr750Mate I can speak with a bit of authority here the ZXR400 can pull 65Hp if unrestricted and fully kitted 42hp is nowhere near the bikes target performance what are you on about?

FROSTY
14th November 2004, 16:33
Mate I can speak with a bit of authority here the ZXR400 can pull 65Hp if unrestricted and fully kitted 42hp is nowhere near the bikes target performance what are you on about?
That was my point exactly redstar-It was performing very badly -Basicly had sucked a kumera -Either in a previous life or more likely due to a couple of MAJOR overrevs by me at pukie there were issues with valves etc.
Second time the performance dropped off it was down to piss poor reassembly work and 2 carb intake rubbers had pulled away inwards--One worse than the other -so the bike was sucking in gobs of air instead of fuel
Thats all fixed now and shes back to normalish

Hoon
14th November 2004, 16:53
Dude even before your last lot of changes Mella Yella was running sweet at AMCC R1 & R2. My bike must be close to the factory 65PS and I couldn't catch you on the back straight. We must both be right up there hp wise as nobody passed me in two rounds on the back straight (cept them pesky 2-strokes under brakes ohh and also a certain SV650 on entry).

KK I'm on the hard lookout for a set of Flatslide carbs (Keihin FCR 32 or 33mm if anyone knows of a set?). After rider improvement, the mods I'm keen on next are external engine mods (ie exhaust, carbs, airbox, ignition etc)

FROSTY
14th November 2004, 20:15
Hoon -Other than the flywheel beeing removed and the carbing issues solved Im waiting for all the other stuff to arrive.
Its not so much raw HP I'm after-its grunt out of corners where the sv's are caning me