race motors

For the kit type two strokes?



No joke, buy the aftermarket bits ya like & dress it yourself - there's very little to these engines (top end rebuild, head, exhaust & intake is a total of like ten fasteners), porting etc is simple enough with plenty of tut threads here & for the money vs the result you'll be far better off with the experience earned. Or for the effort vs the HP... just get a higher quality non-kit motor & spend the difference in mount fabrication (Morini, KTM, Honda, their clones, etc).

Someone has to build & sell "race engines" out of these kit motors it's true - but there's really not that much to it that you'll not have to do yourself again at some point (rebuilds) & as the best tuners never stop tinkerin', why not start at the beginning and save a couple few hunnert?

ive bought parts and whole built motors from arrow and fred, they are both good and they both have motors within that range.

Get the snake pipe and a mid llevel kit

Sorry to say, but any 4hp and above chinadoll is a full race motor.
They simply won't live making this kind of power unless they are HEAVILY modified.
For the money, I'd try a Screaming Roo computer balanced motor.
They are the only vendors I know of doing REAL balancing rather than truing the crank in a lathe.

Keep in mind I have never owned or run a full race chinadoll. I am speaking from my experience with bicycle engines. Not race motors.
But I have been playing with two strokes for over four decades now...

^- i looked at the screaming roo site, and im not too impressed, also they're sold out of their hopped up 350 dollar motor.

I guess I don't really understand how a computer is applied in balancing the motor, but it seems more hype than a performance feature. The impression I get is that they took a lot of desirable buzzwords for bolt hardness and terms from go kart engine building and put them in conjunction with the motor with primarily stock parts.

Ive tried several of the popular engines:
the dax gen iv with the balanced crank
put fred's hop up s on an f80 (stage 2)
bought an gt5l from fred
bought an arrow reed cylinder and block put on a f80
bought a 4.5 street racer engine
bought a snake pipe

Ive spent countless weekends trying to replicate the out of box performance of my arrow 4.5 and now ive got a gt5 from fred, and Id say if you have better things to do and enough money to afford it why not buy a highly tuned motor from fred or dave they've already produced results, why reinvent the wheel

with that snake pipe and either of those motors I saw a difference.

Or prepare to buy a bunch of engines to tear up. maybe you'll get it right the first time.