Help wanted! Big bore kit for my Zongshen 250cc CB replica or XR250R engine?

[Ariel Red Hunter]

Originally Posted by Chineeske

Could resleeving the cilinder together with an oversized piston be an option?

Or is the cilinder wall of these engines too thin?

There is a way to do this, at least in theory. Get rid of the sleeve and have the bore industrial hard chrome plated. Find a piston that will fit first before investing the money in a hard chroming job first, of course. This is kind of "out there" hopping up, but it has been done before, e.g. Briggs & Stratton "Kool Bore" engines...ARH

[timcosby]

Originally Posted by Chineeske

Could resleeving the cilinder together with an oversized piston be an option?

Or is the cilinder wall of these engines too thin?

i think what the hawk is is a honda 125 clone with a big bore kit on it! which is why you dont have room to bore out more. i hadnt looked but probably get into the studs.

[Chineeske]

Originally Posted by timcosby

i think what the hawk is is a honda 125 clone with a big bore kit on it! which is why you dont have room to bore out more. i hadnt looked but probably get into the studs.

Me too honestly speaking... They call the engine I have a CB250 clone, but a CB250 has 2 cylinders and not one thumper I believe

[Megadan]

Originally Posted by Chineeske

Me too honestly speaking... They call the engine I have a CB250 clone, but a CB250 has 2 cylinders and not one thumper I believe

In Technical Honda terms you are correct, the CB250 engine from Honda is a parallel twin. In Chinese clone terms, much like the CG250, the engine in your bike is an upscaled clone of the CB125 single cylinder, so they sell it and classify it as a CB250. In the world of Honda, the CG250 and CB250 1cyl engines don't exist.

[NzBrakelathes]

Originally Posted by Chineeske

Me too honestly speaking... They call the engine I have a CB250 clone, but a CB250 has 2 cylinders and not one thumper I believe

CB = 1 cyl
CBT = 2 cyl

[decaferacer]

[QUOTE=NzBrakelathes;298834]You might be better if with the latest style engine
It’s an 15Kw 18nm and 249cc


hello, i know it's an old post but what engine are you referring to that is 15Kw 18nm and 249cc?


thanks!

[GenericTool]

Originally Posted by decaferacer

...what engine are you referring to that is 15Kw 18nm and 249cc?

I suppose it's similar to CB250 170mm water cooled engine. I have this engine with 14kw on Apollo DB-36 model. Tho NC250 engine variants with 4 valves are close to 20kw


GenericTool

[ghostdancing]

[QUOTE=decaferacer;372973]

Originally Posted by NzBrakelathes

You might be better if with the latest style engine
It’s an 15Kw 18nm and 249cc


hello, i know it's an old post but what engine are you referring to that is 15Kw 18nm and 249cc?
Search for zongshen 172fmm 3-a engine

thanks!