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Motorcycle Repair/Honda sl125 spark but no gas


I have a honda sl 125 motosport. I had the engine redone with new piston, etc and the points and timing are allegedly on point. I got a new Sheng Wey K carburetor and a new gas filter. I see gas to and through the filer and checked the float bowl and it is full. I have spark to the plug but no gas. Tried several times even with ether and can't get a pop. checked the plug and it is never wet. Don't think the carb is squiting gas?  Any suggestions?

Roger, I am not very keen on those Chinese copies of Japanese carburetors. With full choke on, it should load up the spark plug if the main jet and needle jets are all okay.

Do you have good compression?  Should be about 175 psi at least. If significantly lower, the cam timing is probably set wrong.

Double check the ignition timing to verify that you are firing the plug (points opening) at the F mark on the compression stroke, NOT the overlap stroke. If you put the point cam on backwards to the advancer base unit, the spark timing will be on the wrong stroke and it won't fire up at all.

Bill Silver

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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