Small Bore MX advice... Need some help

[Derrick Adams]

I've got a hybrid project quad started for next years MX season. I'm on the bigger side but i've been really wanting to build a small bore racer to play around with.

My local races classify small bore bikes as any 2 stroke under 240cc and any 4 stroke under 390cc

SOoo, if you were going to build a kick butt small bore bike, what engine would you use?

Some of my top contenders are...

CT 240 big bore blaster engine

YZ250F w/ bigbore 290 kit and hotcams stage 1 cams

WR250F w/ bigbore 290 kit and hotcams stage 1 cams

Just throwing it out there, this engine will be going in an old school Kawasaki Tecate 4 with custom JB Racing +4 A-Arms and long travel shocks, JB Racing +.5 swingarm with GT Thunder MX linkage and Lonestar +4 axle (and a whole bunch of other goodies!!)

[bradley300]

honestly, the CT motor isnt all that. There are plenty of faster, cheaper motors out there for blasters. but thats besides the point. i assume you have a blaster chassis? (just a geuss since you mentioned the blaster motor) If you want to stand out, I would go with something besides an out of production blaster motor. I would prefer e-start on those high strung four strokes my self, so i would pick the WR motor

[Punkmaster Flex]

If you going to compete in that class, I'd got with a 4-Strokes 390cc engine. Even a 2-Strokes, 240cc bike will be as quick as a 4-Strokes, 390cc bike, you'll end up having more torque and anyway mixing oil and gaz is a PITA. :blah:

[Punkmaster Flex]

By the way Bradley if you read correctly he said the engine is going to be in a Tecate 4. :p

[250rbadboy]

if you can pick your motor go with the crf250r with the athena 280 bigbore with rhc cam. with some other mods you can get 42hp on dyno.

[greenblood01]

I hope you're going to do something to make that Tecate chassis handle. Don't get me wrong, they're my all time favorite 2 stroke quad, and would love to own one someday, but as far as motocross goes, its probably not such a great idea. Good luck finding aftermarket suspension parts for the Tecate, and when you're front plastic breaks, good luck once again finding replacement plastic.

If I were you I would find a Mojave, do a CWR 330 big bore or even a 370 stroker, along with CWR's valves, cams, port work, carb and intake. Cwr also makes suspension components for the Mojave, you could have one rare, bad *** quad, that would be sweet in the small bore class.

Check out Lurchs Mojave in the "show me you're Mojave section".

[Derrick Adams]

Well, we've since taken that very advise and sold the Tecate chassis. Instead we've picked up a full roller Cannondale chassis. Honda geometry and aluminum frame!

Looks like +3 arms, fox floats, and a YZ250F bored and stroked to a 305 are in the near future. We got connected with some professional Yamaha engine builders that say 43hp is not uncommon with their engines. We're also going to attempt to retro fit some YFZ plastics onto it.

http://i92.photobucket.com/albums/l34/Derrick_Adams/cannondale001.jpg

[250rbadboy]

thats nice but how do you hook the chain up?

[greenblood01]

How hard would it be to flip the axle to get the sprocket on the correct side?

[Derrick Adams]

Flipping the axle and carrier is the right idea. Its been done lots of times. Its as simple as welding on a new brake stay tab on this one. We will have to relocate the chain slider and roller as well, but this is a minor modification.

[ZSNOW]

if i was gonna build a quad like that i would just big bore a 300ex or buy a 250r frame and put a CRF250r motor in it. lot less work. and everything would line up much better..

plus honda rules..:D