Cb250g pistons

[AntonLodwijk]

Hello all,

After I have found a good camchain damper I am now ready to rebuild my CB250g engine.
Normally I would install new piston rings but CMSNL doubled the price of a set of rings (formerly 35 Euro for 2 pistons but now they charge 35 Euro for only one piston). I think that 70 euro for some rings is way too expensive.

Today I saw that they offer .25 oversize non-oem pistons for the CB250k0 for 49.50 Euro complete with rings and piston pin.

Will these pistons fit on a CB250g?

 

[crazypj]

Good question, sorry I don't know answer.
Is the motor the same style as CB350 or is it CB360 style?
If it's CB350 style, pistons will fit.
I can't remember exactly what changed on the later ones but I think compression was lower by 2/10th point or so on later model
Post a pic of engine

 

[AntonLodwijk]

A CB250g engine is the same as a CB360(g) engine, except for the bore etc. The engine is different from the earlier CB250 engines.

However the CB250g piston 13101403000 and/or 13101367000 are superseded by 13101286040 and this nr is also shown for the standard CB250k(..) piston on the pages of CMSNL.

 

[crazypj]

I should have known that but the last time I worked on a 250 G was 1978 ;D
It's same motor as CJ250 (except CJ has one less gear, I put 250G transmission in mine plus bored it to 390cc 8) )
CB360 block will fit, bored to 69mm with Suzuki GS850G pistons gives you a 378cc motor
Isn't the XL125S the same piston?