Who has one? how much of a difference do they make?? I am purchasing one in the winter a 12.7mm stroker crank for one of my bikes and i am wanting to know what will come out of it... how many hp does it gain? top end gain? tourqe gain?? so for anyone that has crank modds please post! thanks

 

I have a 4mm stroker on a 416cc 400ex. Bore and stroke combine for 440cc. I did alot of work all at once, so I can't say what the crank did. My quad does have insane torque. I wear thru grips like they are paper. It is expensive to do, but I think it was worth it, for that quad.

It was $800 for the crank work and the install. The counter balancer is meant to displace 70mm of throw and with it now being 74mm, it does vibrate some. I will guess that with a 12 mil stroker, you will have alot of vibration.

 

a 12 mm stroker crank? why dont you just put a diesel in it? [img]i/expressions/face-icon-small-tongue.gif[/img]

usually adding more stroke will increase your low end torque, the power band hits sooner and you dont have to rev it out as far. The downfall is that the engine will take longer to rev up, and will top out at a lower rpm, a stroker crank will make it easier to lug along on trails, and give you better throttle response, as long as the machine is tuned properly. Expect more overall performance though, the extra displacement will raise your compression ratio, so you will notice better power allt he way around the powerband.

 

Im running a 11 1/2:1 compression right now im upgrading it to 12:1 and dropping the stroker crank in with a weighted flywheel and then on top of that a rev box that lets my go pretty high.. im thinking this will be a great combo im pulling 30hp out of it right now dyno tested but i am for alittle more.. mainly a hck of alot of tourqe b/c im MX racing and i love the holeshot! LOL but thank you for your input i will 100% post a dyno and tell you how everything goes when i get it finished Oh incase your wodering i have Extensive work done the bike already and this is the only thing i can do left! the down side is race gas is required but i dont care

 

Won't lightening the flywheel counter act the stroker torque? Or is it just to get some of the quickness back?

 

I said weighted flywheel.. to add on to the tourqe and then i decided that i will have a lot of tourque between the crank and the flywheel so i am dropping the igniton system in the bike to let it rev way up and quicker so i have insane tourqe with a quick rev im hoping this combo will give me everything im looking for

 

OK tp checks his eyes.[img]i/expressions/face-icon-small-wink.gif[/img]

That makes more sense to me, now. You will have more torque then you will know what do do with.

 

ya i hope so... But i hope its not going 2 be to much.. Its also going to hurt my top end alot from what i understand.. but im going for the track and enduro so does this sound like the set up i need.. My dad was over the other day and i was talking to him about it and he said he doesnt think i will be able to stand the bike up like i used to.. He said you will have alot less snapp b/c the engine has to take so much to rev it up.. also he said 1st-- 3rd will be great but after that im pretty much done for! what do yall think??