Serious question. Has anyone ever died from a bucket crash?

[Skunk]

Well, we all know how that Bimota turned out... they put carbs on it in the end, didn't they?

Some - you can buy them with the EFI. To run well they need carbs... V-due. You know their problem - two pistons. We shall do a single - KISS!

[Ixion]

I think the pressure wave thing might be overstated. After all, power valve systems work around it (or over it really). One might even be able to tap off the PV controller electrics (assuming there is a PV) Otherwise a PV controller box might be a useful start. I have a couple of spares.

And yes, BiMota bent bankrupt trying. But were they not Eytalian? An Eytalian company trying to make something electrical work is obviously on a hiding to nothing, they can't even make headlights work

Whereas Kiwis are very good at electrical things, look at electric fences.

[Skunk]

The pressure wave creates a good draw though the carb at the right time (that's my understanding). PVs change the port timings to broaden the power band.

[Ixion]

PV doesnt change the port timing, it changes the port cross sectional area. Like having skinny pipes on at low revs and fat ones at high revs. I gues sit maybe changes the timing a bit too, cos of the restriction. But mainly its the pipe effective diameter. That's fine though the FI controller just needs to know about that so it gives a bigger squirt as the PV opens.

What the pressure wave mainly does is to block the exhaust port so the charge coming up the transfer ports doesn't bugger straight off out the zorst. (A lot of it does anyway of course, why two smokers have such shit fuel consumption). Thing with a smoker is to just have a dirty big carb and inlet oriface , and either a rotary or reed avlve to stop if all being shot backwards. The effective equivalent of the 4 stroke inlet area is in the transfers. Which is why the poxy carb restriction is such a hassle. I want half an hour alone with the person who invented that rule. Obviously a smokophobic.

[Sully60]

PV doesnt change the port timing, it changes the port cross sectional area.

You're obviously unfamiliar with the Suzuki system then.

I want half an hour alone with the person who invented that rule. Obviously a smokophobic.

Ride this bike back to back with a fast FXR first. It may temper your aggression or spit you off and leave you wanting something a little more sedate.

[k14]

That's a VERY good idea . You will go far. But can you do it with a two stroke? I have never seen a conventional FI setup on a smoker? If you could it would get round that bloody carb restriction rule. A throttle body is not a carb. Right?

But FI usually needs a lot of other sensors beside ignition. Air flow, air temperature etc etc. Some of course are luxuries , for cold runing and such. But are all dispensable? Of course, they could probably be retrofitted.

Hm. Mr Skidmark might not be so far off the mark with his talk of BMWs. They would have injectors of a sensible size (250cc cylinder, maybe not too far out for racing). And wrecked K100s are now fairly common.

This thing is starting to get out of hand. But I will be keeping an eye on Trademe and T&E.

Why not use a injector off a 600?? Rated for a quarter of 120hp, so probably able to do 50hp by itself.

I always thought that having to run the fuel pump would take too much power to make it a feesible idea on such a bike.

FYI, KTM in their 125's (and last year in 250's) had a hybrid fuel injection and carb setup. Great for fuel efficiency and also give a tiny bit more mid range in 0-25% throttle openings. So many sensors though, good luck trying to sort something like that.

[Yow Ling]

PV doesnt change the port timing, it changes the port cross sectional area. Like having skinny pipes on at low revs and fat ones at high revs. I gues sit maybe changes the timing a bit too, cos of the restriction. But mainly its the pipe effective diameter. That's fine though the FI controller just needs to know about that so it gives a bigger squirt as the PV opens.

That is so wrong. The powervalve system (YPVS) is a spool that raises or lowers the height of the exhaust port. It changes the port timing which affects the rpm that max power is made. some powervalve type systems open auxilary exhaust ports either side of the main exhaust and this does the crosssectional are thing (more torque at same rpm) Suzuki and Honda use a chamber which is used to kill the misstimed pressurewave at low rpm.

Fuel injection wont get around the "Carburetor equivelent rule" all it will do is make your bike more complicated you will still be restricted to 24mm hole on 125s , the only way around the rule is run a 100cc engine or a 4 stroke

[F5 Dave]

PV doesnt change the port timing, it changes the port cross sectional area. Like having skinny pipes on at low revs and fat ones at high revs. I gues sit maybe changes the timing a bit too, cos of the restriction. But mainly its the pipe effective diameter. That's fine though the FI controller just needs to know about that so it gives a bigger squirt as the PV opens.

What the pressure wave mainly does is to block the exhaust port so the charge coming up the transfer ports doesn't bugger straight off out the zorst. (A lot of it does anyway of course, why two smokers have such shit fuel consumption). Thing with a smoker is to just have a dirty big carb and inlet oriface , and either a rotary or reed avlve to stop if all being shot backwards. The effective equivalent of the 4 stroke inlet area is in the transfers. Which is why the poxy carb restriction is such a hassle. I want half an hour alone with the person who invented that rule. Obviously a smokophobic.

As said [edit; took me so long to write this Yowling has come on, PS welcome Stanko] most powervalve systems do alter the port timing, quite substantially as well. The old Yamaha system changes the port timing a good 10 degrees or more, & most modern guillotine jobbies do the same. There were a few early attempts by Suzuki/Honda/Kawasaki to open a chamber rather than adjust the port timing (& area of course) but these were quickly modified to emulate the Yamaha system whilst trying not to copy it too closely.

That Kawasaki I am sitting on in Sully’s link has a barrel that was derived from an earlier Suzuki with the non port altering pv. It is actually blocked off, but no matter it will eat & spit out 4 strokes with reckless abandon, & occasionally the rider.

To understand what they were trying to achieve one needs to consider the 2 stroke engine dynamically. [very simplified]; The wave leaving the opening exhaust port travels to the start of the diffuser section of the pipe & returns as a negative pulse (remember wave physics at school) scavenging the engine & assuming the correct frequency for the pipe lengths will even suck some fresh charge out of the engine into the header, - just as the original wave has continued & bounced back off the baffle section of the pipe as a positive wave to stuff it all back into the engine, - just before the port closes.

Of course the word ‘assuming’ meant you were operating at the right engine revs for this to time out well. If at lower revs for example these waves could be quite counter productive. The idea was that if you open up a chamber at the header it would cause a disruption to these waves & then close the chamber when these waves were desirable.

Have a look in a 90s KX250 or similar, both the exhaust port is raised & lowered & conversely a chamber is opened or closed off, but also sub exhaust ports are exposed to alter area as well. These 2 sets of sub ports are at staggered heights as well. Very trick. But not likely to be working after the first owner.


Sheesh this thread has moved on from its original position. My advice is just buy something & go have a go. Many a bucket project has been still-borne with all sorts of lofty ideas sprung from pub talk. Best get something up & running. Then you can alter things bit by bit.

[Skunk]

My advice is just buy something & go have a go. Many a bucket project has been still-borne with all sorts of lofty ideas sprung from pub talk. Best get something up & running. Then you can alter things bit by bit.

Very good advice too.

[TZ350]

You should ride it yourself!
Did you see how OLD the GP winners and place-getters were? Man, they was all old and crinkly.

At the Trophy awards for the bucket gp someone had the wit to call out "See, Bucket Racing is the Youth Sport of New Zealand" when they saw the wrinkly old basterd who came third.

Disrespectfull young F****ks......it's Buckets...

and the people are great fun
.

[gav]

So if you can modify a GSXR600 to run as a 3 cylinder 450, how about running on 1 cylinder as a 150? Be good for 25-30hp?

[Rick 52]

You should ride it yourself!
Did you see how OLD the GP winners and place-getters were? Man, they was all old and crinkly.

You cheeky bugger why how old are you LOL!
I'm only 38 but mentally I'm still 21 I hope I'm still on a bucket when I reach 70

[piston broke]

So if you can modify a GSXR600 to run as a 3 cylinder 450, how about running on 1 cylinder as a 150? Be good for 25-30hp?

?with a switch that turns on the other 3 pots for the straights.

[Kickaha]

Why not use a injector off a 600?? Rated for a quarter of 120hp, so probably able to do 50hp by itself.

I always thought that having to run the fuel pump would take too much power to make it a feesible idea on such a bike.

Someone is already looking at doing that

As said [edit; took me so long to write this Yowling has come on, PS welcome Stanko]

Two logins? ban him

[gav]

Two logins? ban him