1931 Model C running issues

[madmarc0]

I have a 1931 Model C and when I purchased it it had been sitting for some time. I cleaned the GX-1 carb oiled it up and hot wired it with a toggle switch and started it.
I took it for several rides with no issues other than having to re adjust the carb frequently.

Jump to today, I have since re-wired the bike to use the original switches in the dash, got the kit from Harbor vintage cycles for the fiber plates etc, all done and working well.

I took it out for a ride yesterday and it ran and continued to stall like it was running out of gas, I would pull over turn off the ignition put the center stand down turn the ignition on and it would start after 2 or 3 kicks, get back on it and ride it 4 or 5 more blocks, same thing.

I put it on the bench, pulled the carb off cleaned it re adjusted the points got it outside started it and drove it around my building made it almost all the way around it started to sputter cough and stalled, cant start it back up. Put it back inside checked the gas flow to the carb and it seems to be adequate.

Am I missing something here??? When it was hot wired I was able to go 10 miles, yes it backfired but it kept going.

I'm at a loss, the power at the plus side of the coil is over 6 volts like 6.14 or so so that should be good.

I'm thinking timing issue?? I do not have any manuals with the bike as I have not had it that long, can anyone help!

Thanks,
Marc

[Tom Lovejoy]

Totally guessing, but is the gas cap vent plugged? Good luck.

[madmarc0]

Thanks, I'll try it but it ran before, but any and all advice will be taken.

[Steve Slocombe]

Dear Marc, I'd also go for blocked gas cap vent first off. There should be no leather washers under the caps after about 1930 as Harley moved the vent from the top to the side of the cap. That GX carb is a nice find, but all those pot metal Scheblers are hard work compared to the bronze Linkerts. Try downloading for instance the 1935 small twin Riders Handbook from our Virtual Library, and maybe the 1931/2 brochures to get more clues and pictures of what you've got. Just maybe the cylinder is nipping up as it gets hot, so check the oiling. Drain the cases, and put in say 3 handpumps of oil before starting a run, then drain again on return to check oil in the cases. I've had problems with coils, so pull the plug wire and make sure there is a bit of bare wire exposed before you jam it right back down. Points can always be checked, and a dud generator can cause the bike to die just like fuel loss. Harley didn't use a gas filter until 1932, and that modern gas strips all kind of junk off the inside of the tanks. Check fuel lines again, plus inside the tanks, plus the float bowl on the carburettor, plus the condition of the spark plug. Nice bike, good luck, have fun.

[madmarc0]

Thank you! P.S. what did you mean by "nipping" I did check the oiling it seems fine.

[madmarc0]

Thank you! P.S. what did you mean by "nipping" I did check the oiling it seems fine.

Update: I checked everything again it seems like the cap was plugged but I suspect it was clogged before.

I put a new plug in this time an AC plug and now it runs fine no more popping and stalling seems like a new bike again!

[Tom Lovejoy]

Right on! have fun!