recommended bike motor?

[jambalini]

Honda RS125 GP motor!!

Well here in the UK, we don't go into build your own chainsaws for racing etc, but I really wish we did. Sounds loads of fun. But what I would like to add is that I think you are all missing out probably the best bike engine to use although one Guy was close. I have just retired from 125cc road racing I for power, high revs, and very light weight, you should try and get hold of a Honda RS125 GP motor. This motor is very simular to the Honda CR crossers but basically will rev higher but does have a narrower power band (8000rpm to 14000rpm). A 1998 or newer motor would be best as you can get 45 BHP out of them quite easily. Can you get hold of them easily in the states? I probably won't be butchering my race bike to try this but would love to know if anyone has used this motor before and see a pic.

Have fun

Andy

 

[weimedog]

So how do you deal with the water cooling requiement?

I guess for a couple of seconds it doesn't matter. But for one thats to be run more..why not go back to the late 1970's like the last air cooled KX125 or CR125? There were a ton of air cooled Yamaha YZ125 from that era out there. Parts are still around for those and with the AHMRA vintage racing series their are even more parts available.


If the later model water coolers are still the desire...the best were the Yamaha YZ125's from yr 2000 on, they were the class of that displacement with the best power band and almost the best peak power. Also the KTM125's (now 144's) from around 2001 on were the screamers of that class with s couple of years where they were in the high 30's in real HP.

 

[066logger]

i would think that a cr 500 or ktm open class 2 stroke would be bad real bad. u should build a 4 stroke yz 450 or something like that just for the heck of it i think they rev out at 12000 or 13000 and make close to what an open class 2 stroke will make. somewhere in the mid 50s or so. that would be badder yet.

 

[Trever]

Cheap power

Yep. I have it torn down now. Looking forward to this build, but have projects in front of it. I'll keep you all posted.

Trever

 

[weimedog]

What era are you talking about? Throughout the 90's KTM made power on the dyno but didn't have it on the track. Somewhere around 2000 and up they got it all together but by then the big four had lost interest in two strokes.

My favorite if you could find on would be the '96 CR250! FAST AS #### on the track. Not sure how that would that would translate to a log.

From 2001 on