ESE's works engine tuner

[crazy man]

This maybe the answer, or maybe not, food for thought anyway ....



Page 600 has quotes from Frits and Jan about this.

thanks the one thing l have changed is the expansion chambers and was ok before . l know the stingers are not the best . bent up years ago so will replace them first

[speedpro]

Are these the bikes that don't have a variable rear CVT pulley? I think on these the motor pivots to compensate for variations in the front CVT pulley. The rollers instead of working against a spring on the rear CVT pulley work against a spring holding the motor against the belt.

[speedpro]

thanks the one thing l have changed is the expansion chambers and was ok before . l know the stingers are not the best . bent up years ago so will replace them first

You should be able to get someone to machine up a nice precision nozzle and then just use any old piece of tube to get the exhaust into the muffler. With a bit of thought you could have replaceable inserts of different size. I've tried different nozzles and got interesting results on the dyno.

[husaberg]

anyone know why on the run down of my 2 stroke it likes niping up? what do l look for ..thanks

My mussing is this.
On run down from high revs it will have high revs closed throttle closed throttle equals no fuel no fuel equals no oil.Plus the dyno drives the engine on longer than it would be on overun on the track.
I believe on the KTM 125 GP bike the solution was a injector to supply fuel on the Aprilia not sure. prossably a 45 kg physco rider that never backed of the throttle.They possibly did something tricky and secret...
i seem to remember Frits saying something about deto on overun as well.

[speedpro]

Closed throttle results in no air blowing through the engine so the oil stays there, more or less. Extended run down on a dyno is never good though which is one reason they should all have a roller brake.

[crazy man]

My mussing is this.
On run down from high revs it will have high revs closed throttle closed throttle equals no fuel no fuel equals no oil.Plus the dyno drives the engine on longer than it would be on overun on the track.
I believe on the KTM 125 GP bike the solution was a injector to supply fuel on the Aprilia not sure. prossably a 450 kg physco rider that never backed of the throttle.They possibly did something tricky and secret...
i seem to remember Frits saying something about deto on overun as well.

that was my first thought but was ok before changing the chambers may do what speedpro says for starters and put the det counter on and see what its doing

[TZ350]

Are these the bikes that don't have a variable rear CVT pulley? I think on these the motor pivots to compensate for variations in the front CVT pulley. The rollers instead of working against a spring on the rear CVT pulley work against a spring holding the motor against the belt.

Yes, looking at it you could be right, I don't know anything about them realy, just what I can surmise from the pictures.



But I can't see where the spring would be.



Here is a bunch of guys push starting their CVT race bikes, I didn't think you could push start a normal CVT so there must be something different about them like you say, and you maybe right, no rear clutch or rear variable pully.

[wax]

Polaris atv are big on there cvt and so are snowmobiles.
Ebay motors may be your friend

[husaberg]

Yes, looking at it you could be right, I don't know anything about them realy, just what I can surmise from the pictures.



I can't see where the spring would be.



Here is a bunch of guys push starting their CVT race bikes, I didn't think you could push start a normal CVT so there must be something different about them like you say, no rear clutch and variable pully, you maybe right.

Are they like a Peugeot or similar moped pnly race class?

TZ the Husky and the Rokon both had reduction boxs, why...With the CVT you lose your primary reduction remember.............
if you are dead keen pn the CVT, i would suggest you make up a basic crankcase first like the one in the link Wax knows the one i mean...........

[TZ350]

i seem to remember Frits saying something about deto on overun as well.

I can say hand on heart that the Beast has been known to deto on over run and part throttle.

[TZ350]

if you are dead keen pn the CVT, i would suggest you make up a basic crankcase first like the one in the link Wax knows the one i mean...........

Possibly a rear rotary valve like the Aprilia and a water cooled 100cc after market performance cylinder.

[husaberg]

Possibly a rear rotary valve like the Aprilia and a water cooled 100cc after market performance cylinder.

Hell no...... side sucker rotary valve..............like the RSW Aprilia Sorry jan and frits i are not sure why the RSA had a rear disk valve????

Was it just to slim up the engine and bodywork all that extra gears and intricacies make my head spin.................
I seem to remember a quote from Frits or Jan saying they wouldn't bother with the layout again i think because of the weight bias as well?

you could design one for the Air cooled GP cylinder and a LC performance cylinder
if it was made with a sandwich style construction you could make it like in the pic (but out of 4 sections of flat plate)
that way most of the basic cutting out could be done fast with a bandsaw. then only the final tidy up with a Mill.

[Frits Overmars]

Re the Frits post above if Frits hits reply with quote he will see what i did. ....Mr Mentaltrousers showed me how as he was sick of my over sized pics so thanks Mr T.

Thank you so much for posting my Tower of Pisa-story, Husa; I think I'll stick to simpler things like two-stroke development .
I hit that 'reply with quote' button and then for a fraction of a second your code was visible; I just managed to take a screenshot.

Husa pointed me towards some pictures of CVT racers on the Pit-Lane.biz site. Looking at the picture of this CVT racer it looks like there is no reduction gear box and that the front chain sprocket is behind the rear CVT pully and that they rely on the big rear sprocket to get sufficent overall gear reduction.
Originaly I had thought of having the rear cvt pully driving a 3:1 reduction gear set but the big rear sprocket setup is much simpler. All I have to do is find a big enough rear CVT pully so I can have a low enough first gear for starting off.

Are these the bikes that don't have a variable rear CVT pulley? I think on these the motor pivots to compensate for variations in the front CVT pulley. The rollers instead of working against a spring on the rear CVT pulley work against a spring holding the motor against the belt.

...But I can't see where the spring would be.

In the first picture you can see the horizontal spring, nested in the frame. The complete engine, including the pipe, is hung by the head (they do that to engines in France; for humans they have the guillotine).
The spring keeps the V-belt in tension. And in case you want to kick the revs up a bit when exiting a corner, there's a foot pedal with which the rider can put a bit more tension on the belt and thus force the primary heaves wider apart and lower the gearing.

But you don't want to go there, TeeZee. Only one heave of the front pully moves axially; the other front heave and both heaves of the rear pully are fixed.
That not only means that the range from shortest to longest ratio is only half of what it could be on a decent vario; it also means that the belt is forced to run skew most of the time.

[TZ350]

But you don't want to go there, TeeZee.

Thanks for the heads up ... interesting bikes though, great pictures.

[TZ350]

Ok so that mounting is where they swing the engine assembly from.