VH500 running rich

[Peter Fletcher]

I had a similar problem. It turned out that whilst the pilot jet seemed to be tight it wasn’t seating properly. As a result the carb was impossible to tune, very frustrating until I eventually found the cause. Worth checking.

[dennis.t]

Thanks to everyone who replied.
After some lengthy investigations today I think the problem is an intermittent leak on the float needle. I noticed fuel gathering on the throttle stop presumably from the carb overfilling overnight when I left the fuel tap on deliberately.
I have replaced the float needle. Good tip about a blob of solder on the brass float to lower the fuel level as that might be necessary.
I checked the jet needle and it is a new 'c' type from Burlen.
Am I correct in assuming that all Monobloc 376 bodies with the same bore are identical? I ask because I could not get the correct carb body so I bought one with the right bore and fitted jets etc to suit the VH500 spec, as listed by Brian above.
I do have a screw on gauze air filter but it was not on the carb during this testing so that I can see what is going on (fire extinguisher at the ready!).
Dennis

[Roger Gwynn]

I am 90% sure that all bodies are the same but there are variations in the spray tube in the jet block, which may be included as part of the body.

[dennis.t]

Roger,
Many thanks I'll check the jet block spec on the Burlen website. The replacement float needle seems to have worked to stop the carb flooding but starting is still a lottery.
Dennis

[Markaj]

Had exactly the same thing many moons ago when learning the black art of keeping old wrecks on the road. It would run - sort of, enough to get me to the pub, even if it did eight stroke a bit.
The solution - I'd left out a paper washer that the jet block sits on in the carb body. I think the old one fell to bits when I'd stripped the carb down & got forgotten, & not replaced.
So if you have stripped the carb, did you remember the paper washer?!

[dennis.t]

Yes I did thank you. I replaced all of the gaskets and washers and the flange O ring. Having stopped the carb flooding I have not had a chance to run the engine yet.
Dennis