L.A sleeve 385 big bore kit

[courchaine]

http://www.motojoe.com/motojoe.htm

Look at the yamaha warrior/raptor 350 385 big bore kit......sounds good to me and would probably be powerfull....the price seems to be good....I don't think it would overheat but y would definatly not run this setup without oil cooler.......


Max

 

[xj4m3]

seems ok but for that price why not do a drop in stroker kit from hotrods and have more ccs plus not as big of a bore size

 

[yamarider]

Ugh, for that price i'd spend the extra few bucks and do the work installing the hotrods stroker. I think that's just a ripoff. I mean, FST sells their kits for $650 and that includes stroking your crank and the bigger sleeve and piston. Hell, Cycle Works sells a 400 big bore for $325 and you can actually do an overbore on that sleeve when the time comes for a rebuild, instead of buying a whole new kit and starting over. In my opinion, that kit is probably the worst way to go for gains vs money spent.

 

[jasonp]

Weird 85mm bore is a 366cc not a 385cc.
Either way you'll get more power/torque stroking the motor then you would boring it. The warrior/raptor is already over square on bore to stroke so it would help more to go stroke. More you bore IMO the more your turning the motor in the a high rev'er... or that's where it would make it's power. So you'd have to completment that with a strong cam that is made for high rpm to get the most out of this type of setup.. head mods would help as well.

 

[dave76]

Like Jason said the Warrior motor already is a short stroke motor, increasing the bore any bigger is really throwing the ratio off, just making it more of a high RPM motor, with poor breathing capabilities at high RPM, not to say your killing low end even more. The bore would have to be 87mm to get 385cc. With two big valves flapping away your best bet is to add stroke to this bitch.

 

[jasonp]

Yeah it's all about piston speed when taking advantage of the 2 valve head. Since with a stroker engine the piston speed is moving faster then it would with a big bore small stroke at the same rpm it take more advange of the port and head as well of the fact that your moving the crank pin outward on the crank helps create more torque.
This is why you have to rev a big bore engine so high to get the power out of it... piston speed, get's the port volecity up and makes the 2 valve head work start to work. Just looking at the warriors bore/stroke spec's you'd think it's motor that loves to rev and make power up there. When really it doesn't at all!

 

[vestige019]

wait so on a warrior with the stock piston, gettin a stoker for it would make more of a difference than reboring it with 85mm??

 

[jasonp]

Yes.. . You'll gain more torque and hp stroking it then boring it.

 

[dave76]

By stroking it, your actually putting the Warrior motor were it likes to breath. A stroker also adds duration to the piston at top and bottom dead center. The longer throw lets the piston sit on top longer and swing past bottom dead quicker.

 

[vestige019]

oh
alright thanks

ive taking apart my engine before but not my transmission

when i finaly did get sum money do u think it be hard for sumone like me to stroke it?

 

[dave76]

No it's strait forward, just pay attention to the washers that come out, and a good manuel will help like the factory service manuel. After you put the trans back together you spin the main shaft and shift the drum through all the gears to see if ther working properly. Thats it.