Hi Mixxer.

As I said in the other post I'm thinking about rebuild the engine of my YFZ. It runs great but it's 3 years old without a breakdown, many races and I prefer rebuild and improve before a future problem.

I've readed too much about WR cranks, big bores 480, stock bore, high compression pistons.... etc... and I don´t know what I need to improve my 06 YFZ...

I race supermoto and I need power but also considering the reliability. My engine mods are: GYTR jetting, Pro Design pro flow kit, Cam mod, FMF 4.1 + powerbomb. I'm happy about the present performance but I'd like to take this opportunity to improve the engine.

What Venom piston do you recommend?? Should I change the crank? What crank??, I think that I would have to change the cylinder as well, wouldn´t I? Do you sell the complete kit??

Thanks!!

Sorry for my english

great set of questions...

here goes...

you never really know how long a crank will last in a high performance machine..... BUT if you did need replacement, i prefer the quality and balance of the 06 & up yfz cranks....

that pro design intake is still based around the stock filter to carb boot assembly.... so there would be power & powerband to be had by switching intakes...

carb boring is failrly inexpensive...and makes for power across the board going from 39 to 42mm..

if you need to stay within displacement limits... then you would only need to de-glaze your cylinder and put in a new piston...

if you could go to a big bore setup...they always make for a nice power boost over the whole band....

porting will also make for a nice boost across the board...

what is your budget...and what are your class displacement limits??

with that info i can give you a recipe for most HP for least $$ spent...

" BUT if you did need replacement, i prefer the quality and balance of the 06 & up yfz cranks.... "


If you are to replace the crank why wouldnt you go wr and how are the 06 better then the 04-05 cranks other then the extra 10cc and shorter rod?

the WR crank is too light to have adequate inertia for the atv driveline... and what you gain from it is the 10cc's also...

the 06 and up cranks make more hp with the correct inertia...as well as the added 10cc's...slight bump in compression too...

Great Mixxer, thank you very much.

The most important problem (apart from $$$$, :-) ) is the distance. I live in Spain and I'd like to bore my carb, port and everything you can do with my engine but the transport cost, the time without ATV and the transport risk stop me.

As a result of my post about Venom RAT I readed about intakes and I think that the FCI intake could be a good option because I can use the original box without cap. I think that the ESR INTAKE doesn´t let me to use the original box, is it true?

What's the meaning of de-glaze?? is it the same than plating with nicasil?? Is it better than buying a new cylinder??

I don´t want a high compression piston because here the race gas is difficult to reach and very expensive....

Thank you!!

I disagree with your thoughts on the wr and how does the 06 crank add compression?

they are not thoughts...they are dyno tested and proven fact.... if you have a problem with it, so sorry..... invest $18,000 into your own dyno and you can test it all you want...

if you add 10 cc's of displacement via a "small stroker crank"... you are still using the same combustion chamber ...so 10 more cc's compressed into the same combustion chamber makes for higher compression.... happens every time...LOL

hope that clears things up for you... :)

de-glaze is a way to freshen up the cylinder honing so that the new piston rings have a fresh mating surface to break them in to... without it, the rings would never finish break-in and not make for a perfect sealing surface... any shop shuld be able to do it for you at a minimal cost... as long as there is nothing but normal wear to your cylinder, deglazing is all that will be necessary...

true... the ESR is an open element system....

Yes, I was right!! But the problem is that in Spain that proccess has a strange name "nicasilar" :-)

I wait for your recipe taking into account my situation

that's nicasil.... nickel carbibe silicon plating..... super hard and long wearing... it's what most high output cylinders have for a bore plating.... all you need to do is hone\ de-glaze to break in fresh rings

Mixxer, I've just one question.

I have been thinking about buying your 480 piston for stock cylinder but I don´t know what would be the cylinder set up needed to go with that piston. I suppose that once I have the piston I should send the piston and the cylinder to a specialist for adjusting the cylinder to the new piston.... is it true?

if you get a Venom big bore kit... (we use your stock cylinder as a core )... you would get a complete kit with the cylinder perfectly bored and re-plated for the piston + complete top end gasket kit + complete piston kit....

no need to send your cylinder anywhere else...