bore kit

[jacob]

How big are all the bore kits i could buy for the warrior and how much do they cost? thanks guys I'm lookin at gettin a bore kit but really don't know much about em other than they'll make my bike way faster and my motor bigger

 

[usdsk8er540]

wont really make your bike that faster. it will make the motor displacement bigger though. the 400 stroker will add a lot of torque, but not speed. going up some teeth on your front sprocket will give you more top end, but less acceleration. so anyways, the big bore kits wont really make it "way faster", just more torque which you can turn into more top end. hope that helps some.

 

[jacob]

yeah i want to be real quick and explosive in the mid range i hardly ever get to 6th gear in the type of riding i do

 

[usdsk8er540]

well i would check your gearing first. you may be able to get a little more "pep" with a gearing change for a lot cheaper than a big bore kit.

 

[dave76]

2mm is the most you can safely bore the stock Warrior sleeve. Stock is 83mm and 2mm over is 85mm or 366cc The best thing about the bigbore kits is that they add compression, this is were some low end torque is made up, stock is only 9.2:1 and Weisco is 10.25:1 and a JE is 10.75:1 or (12.1 which requires mixing some race high octane fuel). A company called CWR (cycle works racing) has a sleeve kit that allows an 89mm bore which with the stock 64.5mm stroke gives 401.3cc. I'm sure this motor makes a lot more power then stock however it'll be a rever with that short stroke and will lack torque on the bottom end. Hotrods makes a stroker kit with a 71.5mm stroker crank and a 84mm bore makes 396.3cc but will have gobs of torque at the lower rpms. And of course the ultimate torque monsters are FSTs 446 and CWRs 460 kits. Due to the Warriors two valve head I would not be worried about building power at a high RPM as you will be basically at a loss due to breathing ability. The Warrior head actually flows very good but at low RPMs and low port velocities, once the RPMs get up it starts to inhibit flow. If your doing this because you plan to race it, I will say get the for sale sign and buy a quad like a 400 or 450 ment for racing. the Warrior can be a good XC machine but will still cost an arm and a leg. Otherwize you'll enjoy it.

 

[jasonp]

Yes what is interesting is that the warriors head does actually flow quite well for the size of the engine. I think the limiting factor is it's shorter stroke and even with a bigger bore the stroke is still playing a big factor. That is my opinion is that the shorter stroke is causing the cylindernot to fill as the piston speed is so fast in the BDC and TDC ranges. (help me out here dave) It's just so under square.(or would that be over square, dave?) Really with all the mods I got I don't see more then 9000 rpm of peak power. This is why my limiter is set at 9500 rpm. There is no reason to rev it that hard when there is no power up there. It will go past 11,000 rpm in 6th but your not gaining anything reving that hard and just shorting the life of the engine.
Stroker kits you will always feel more from.
I agree though with dave that if you want to start racing put the for sale sign up as the chassis is pretty dated. No effence to anybody.

 

[dave76]

Lol Ja you corrected right, oversquare. But yeah thats why faster reving engines love multiple valve heads, because the individual ports are kept at a smaller size keeping velocity up as opposed to massivly porting a 2 valver which reduces the velocity. However a large port 2 valve motor with very high compression works well too, but requires high octane fuel. For example people have been racing the old 2 valve Suzuki GS and Kawi KZ motors for years in drag racing.