Running out of gas : V-Twin Forum: Harley Davidson Forums

heavyduty · 04-15-2009, 06:17 PM

95" twin cam open air cleaner S.E.cv 44 carb. Run great til 3500 rpms. Seems to be running out of gas. Check float adj.If I bend float tab anymore, carb overfills. Petcock has good flow. Jets in the carb are 48 slow, 195 main which is what I have run for a couple years. Any suggestions what the hell is going on with thing? I don't think that it is an ignition problem but don't know? Thanks!

Mother · 04-15-2009, 09:08 PM

Is it the stock petcock? I had to switch to a Pingel. It was running out of gas shifting in to 3rd gear on the dyno. Swapped petcocks and problem fixed.

heavyduty · 04-16-2009, 08:03 AM

It is not stock aftermarket high flow, pulled hose off at carb, good flow

rcsoftail · 04-16-2009, 01:21 PM

Are you sure the slide is raising? Mybe you have a hole in the rubber diaphram or it is not fully seated, which will keep it from opening. Do you have another ignition you can plug in to make sure there's nothing wrong with the rev limiter?

route66paul · 04-16-2009, 01:57 PM

How is the accelerator pump?

heavyduty · 04-16-2009, 02:21 PM

This is a problem I have been fighting for some time. Adjusted float due to fuel in the air filter. This is a fairly new carb. But I did look at the accelerator pump and diaphram, looks good. I can run the bike past 3500 rpms but after about 5 seconds starts backfiring out of carb just as if it was running out of gas. Ignition is a screamin eagle for a 1999 bagger, I think the rev limit in it is 7000rpm, but not for sure. Someone had mentioned exhaust problem, which I had changed the exhaust and I can't remember but that might be when all of the problems started, gas in air filter. The exhaust I put on was a Thunderheader

rcsoftail · 04-16-2009, 11:43 PM

If it started with the exhaust, that's where I would start. I think those have some sort of vanes for baffles. Maybe one has broke and is causing blockage when past 3500rpm. I think an exhaust blockage could cause the results you are seeing.

heavyduty · 04-17-2009, 12:48 AM

Thanks! Will try previous exhaust. Will let you know! Thanks!

springer- · 04-17-2009, 07:53 AM

Also check your fuel line routing. If the fuel line is touching the engine, cylinder, heads etc it could be causing a vapor lock in the fuel line. This is especially true if you have an in-line fuel filter. The in-line fuel filter can get hot and cause a vapor lock. When this occurs, the fuel flows great when checked but only flows enough for lower RPM operation when the engine is running. If it has a in-line filter, remove it and run a straight line to the carb. Make sure it doesn't touch anything hot.