250-500cc WR 300 race head short review

Changing needle and needle position is very easy. I think there is a thread about it here somewhere. It takes me about 3 minutes to change it. to me it soiunds like you bike would benefit of a leaner jetting. A smaller pilotjet, and lowered needle. You don´t need to remove the carb, just loosen the hoseclamps and twist it.
I´ll try to put in some pics of my bike with the icetyres on it=).

Johnny

Squish band is very important for 4 stroke not for 2 stroke LOL

If you really want to wake up that motor,try a CEL needle in the 3rd clip.wakes it up on the bottem and rips to a nice overrev.

I think you got that backwards. unless you were being sarcastic.

For 4 stroke, during intake stroke correct squish band will generate high turbulence in the combustion chamber. Turbulence in the chamber promotes better atomization and less separation of the fuel and air, encouraging it to burn.
For 2 stroke, everytime piston goes down that is a power stroke..
Of course piston to head clearance have to be enought also 2 stroke.

I know what it is,what I was saying was,imo it is more important on a 2stroke

My both Stock and race head have 2.5mm ( 0.098") squish band clearance. So if I want correct clearance I have to modify stock head. Race head modification will get too much comp for me. Btw with race head it is easier to start, it usually need one kick.

2.5mm from the race head, too? That is ridiculous. These engines run much better with squish in the 1-1.25mm range. But you can't always just shave it... you may have to take some material out of the bowl to keep the compression from going too high. The difference is amazing.

I checked squish band clearance again about 4 times and ended up 2.1mm clearance. It was bit difficult because solder dia. was only 2mm. But stock and race head have same squish band clearance.

Btw what do you think if I modify stock head about same comp. rate than race head and set up correct squish band clearance. How much better is modified stock head than race head?

I'd bolt each head on and check maximum kicking compression pressure. Take the head with LOWEST compression pressure and cut that one. Just make sure your machinist checks to make sure there's enough metal.

Race head have smaller combustion chamber. I just thinking how much correct squish band clearance Increase performance because when you set up squish band clearance you also get higher comp rate.

A correct squish band makes a very noticeable improvement. Cut the head then check your compression again. If it's too high you need to have some material removed from the bowl. That's why I'd recommend cutting the head with the lowest compression.

My stock head is soon modified and then I'll get my bike to dyno with modified stock head and race head.

look forward to seeing the dyno results ......hurry up I'm running out of popcorn!

LOL guess which one is better

please tell

I don't know but I'm down to licking the butter off my fingers waiting . So ..........?

Ok I can't wait....the modified head by 2 hp! ?

Not dyno yet, i have spiketyres now. Later...

well? im curious dam weekends the suspense it killing me