Honda CM 250/rebel valve clearance?

[texaschris]

Hey guys,

Just put a cm250 motor in my cm125 (the 125 motor was fucked).

As I don't have a manual for the new motor does anyone know what the valve clearance should be for the cm250?

The CMs are supposed to be pretty similar to the rebels, but don't know if those similarities go as far as valve clearances. Found stuff online about valves for rebel 250s but I'm not confident that they are defiantly the same? Can anyone confirm?

Even the info on rebels I've found is pretty inconsistant, ranging from 0.05mm up to 0.10mm. That seems like a big diffenence for valves. Some places even mention more clearance for the exsuast than the intake?

The cm125 manual says 0.05mm, but again not confident that would nessicarily apply.

Any help/clues would be greatly appreciated.
Thanks,
Chris

[hmmmnz]

i tend to run bikes with rocker arms, 0.07mm for intake and 0.10mm for exhaust,
there is no hard and fast rule, although i wouldnt go any tighter than
0.05mm on intake or exhaust
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[texaschris]

Cheers. Appreciate the reply.

Opened it up last night just to see where they were at and they were all over 0.10mm. Could even get a 0.15mm feeler in a couple.

dropped them down to 0.06/0.07ish and it seemed to be better.

But if factory spec is 0.05mm, I'd like to set it right. Just don't want to assume thats the right number though and have them too tight.

Thanks,
Chris

[hmmmnz]

its a guide, they never say 0.05, they will always say 0.05-0.10mm
thats why i set the intake at the half way mark, and because of the nature of the exhaust valve expanding under heat, i go for the 0.10mm for clearance


some times you'll see maufactures say 0.07-0.13mm for the exhaust, where the intake is 0.05-0.10, because they know the valve expands under the heat, and some times they just say the same for both intake and exhaust, i'd still go looser on a exhaust valve

a loose valve clearance is ok, a tight valve clearance is bad, burny valves ensue if the clearances get too tight that the valve doesnt competly close
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Lord Percy]

Youtube linky - 0.06mm-0.10mm

https://i58.tinypic.com/29c3yav.png

I think you need to wear cool shades and a bandanna like that American badass too.

[texaschris]

AAAAHHHH! It must have been my lack of bandana and shades in the workshop that was throwing it off! haha

Thanks guys, seems like I've got them bout right then.

Chris