C77 Jet sizes?

[DianneB]

I have been chasing a problem with my 1967 C77 for the past year. It seems to be running badly over rich. I get one or two runs from a set of plugs before they are so fouled that they wont fire any more.

I have overhauled the carb, checked that it has the right jets (by number), adjusted the needle and it STILL turns the plugs "black and fuzzy" after an hour or two of riding. All I can think of is that somebody may have drilled out the jets or that the jets are badly worn.

Does anybody know the orifice diameter in each of the OEM jets? At least I could measure these and make sure they are actually the right size.....

[Tim Allman]

The orifice size is stamped on the jet itself in units of 1e-2 mm. So a jet stamped 125 would have an opening of 1.25 mm.

[mark acker]

I have been chasing a problem with my 1967 C77 for the past year. It seems to be running badly over rich. I get one or two runs from a set of plugs before they are so fouled that they wont fire any more.

I have overhauled the carb, checked that it has the right jets (by number), adjusted the needle and it STILL turns the plugs "black and fuzzy" after an hour or two of riding. All I can think of is that somebody may have drilled out the jets or that the jets are badly worn.

Does anybody know the orifice diameter in each of the OEM jets? At least I could measure these and make sure they are actually the right size.....

[mark acker]

I have been chasing a problem with my 1967 C77 for the past year. It seems to be running badly over rich. I get one or two runs from a set of plugs before they are so fouled that they wont fire any more.

I have overhauled the carb, checked that it has the right jets (by number), adjusted the needle and it STILL turns the plugs "black and fuzzy" after an hour or two of riding. All I can think of is that somebody may have drilled out the jets or that the jets are badly worn.

Does anybody know the orifice diameter in each of the OEM jets? At least I could measure these and make sure they are actually the right size.....

[Geoff Hastings]

I had a similar problem on my CA77, jetting was fine, air filter was new, checked the float height, way off. Reset the height, now no more wet plugs.

[G-Man]

Carb settings...

G