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Just built a 125 reedvalve motor...yes 125cc with a centre squish centre plug head. Scootopia clubman . I've set the timing at 17°btdc . I've not checked what was in the carb jet/needle wise ...just put it on and it fired up second kick ...it seems to run ok but would like peoples thoughts on jet and needle combos. I've never set up one of these carbs before hence asking on here .

Cheers Simon

I can give you 28mm info bruv

hullygully wrote:I can give you 28mm info bruv

What was the set up Mickey

Try starting with a 38 pilot jet , JJH needle mid clip pos’n and main in the 115 -120 region

drivera wrote:Try starting with a 38 pilot jet , JJH needle mid clip pos’n and main in the 115 -120 region

That's what's on the menu tonight.... think in needs a bigger pilot a 40 or 45... which I don't have yet. Cheers Simon

These are some notes of mine, I was setting one up on a stage 4 200 with a BGM pipe, I know it's nothing like but may be of use to you.


It ran well with all the pilots BUT when it got warm it would flood easily when trying to start after a short stop, like getting fuel.


Also the float level seems quite critical on these carbs, to prevent the flooding issue, I set it a tad lower than spec and it would run out of fuel if you were flat out for a mile or two. A mm either way and next thing it would be flooding and coming out of overflow. Once set I liked the carb though, but beware a pal bought one on eBay and we tried to use it on his RT and it was shite, in the end I tried the jets etc out of mine and the drillings in his carb were different and we couldn't swap some parts, I put my carb on his motor and it ran fine.

OKO carb
122 main
45 pilot
JJK needle middle

Keihin carb OKO

Pilot 48 was 50 Whitby maybe smaller? Drop to 45?

air screw 1 out

Main 125 now was 130 Whitby too rich

JJM too now was JJK top Whitby

Main was 125 with JJH 2nd
try JJK top clip.