getting the most power

[yamahaman623]

does anyone know any little things to do to a yfz to make it faster. im not talking about piston cams etc. i want to know if there are little tricks i can do to get more power. if you know anything at all post it up.

[jersey devil]

Originally posted by yamahaman623
does anyone know any little things to do to a yfz to make it faster. im not talking about piston cams etc. i want to know if there are little tricks i can do to get more power. if you know anything at all post it up.

Is it in stock form now or have you made any mods at all?

[yamahaman623]

it has the normal mods that everyone does. sorry i dont want to give all of them out because i try to keep it a secret from my buddy. but it most off the shelf parts plus a port job

[jersey devil]

I see below your name with your post it says you are a drag racer.So I assume you are drag racing your quad.
If you say you have all the usual mods and don't want to change cams or a piston to up the compression then you pretty much have it covered.
Have you done the cam mod?Of course you can play with the gearing.It is not clear what you are doing?Dragging or riding the woods,trails,or mxing?
Why not put a higher compression piston and cams.Port jobs are fine but you don't get the full advantage unless you change the cams with more lift to flow more air.. therefore more fuel and more power.

[Ride1Rob]

The cams in the YFZ are very good stock cams. But even with more aggressive aftermarket cams you're wasting your money without a nice port job. You'll see more benefits if the head is ported and an aftermarket intake to bring in more air. Since you have the port job add an aftermarket intake if you haven't already.

[yamahaman623]

thanks for the help but my engine is already built. i was just looking for little hints or tricks to get maybe one hp more out. or like a mod like the cam mod or the yz clutch mod

[Ride1Rob]

Well it's pretty hard for people to answer your question when no one knows what's been done to your bike or what's been added or not.

[yamahaman623]

ok ill tell you. it has cams, piston, air filter, jets, sparks pipe, dynatek igntion, cam mod, and sparks bypass plug. there might be a couple other little things im missing but thats the most of it

[kawiracerj]

have you tried the yz timing trick?

[yamahaman623]

yeah i did that i just called it the cam mod when i listed my parts

[Ride1Rob]

Unless you want to go bigbore, stroke it, oversized valves/angled valve job or bored carb there's really not much more to be done. Nothing that's going to show nice performance gains.

[yamahaman623]

well see that is exactly what i want to find things that might give me one or two more hp becasue i already knew i was to the max on off the shelf things. but rob how much does boring a carb help.

[Ride1Rob]

Boring the carb will help the bike to run better on mid and top end. The bigger the bore on the carb, the more you loose on bottom end hit and the more you gain on top. I'd think that boring to 41mm would be the best of both worlds considering how much bottom these bikes already have. If you're a MXer then you probably should leave it stock for the torque. If you're into drag racing then boring the carb will benefit you alot more.

[yamahaman623]

ive heard of a taper bore and a straight bore is there a difference

[Ride1Rob]

There is quite a bit of difference between the two. Mine is tapered and this is basically done for more efficient airflow. The air is less prone to tumble once it hits the front of the carb and the velocity of the air stays the same. Probably even gets faster because of less tumbling. This will help from bottom to topend performance. Boring pushes more air through the carb but the velocity of the air slows down. Low to mid throttle the bike may suffer quite a bit if it's bored too big. On top end the velocity picks up and the bike performs better because there's more air being pushed through. There's a guy here that bored his to 43 or 44. His bike has no bottom end hit and starts to deliver nice power around mid 3rd gear. Rode like a Banshee to me.