can't get an old bike started.

[throttlejunkie]

So I am trying to revive an '82 CB 750 for my gf, I've got spark, fuel, and compression and the timing is as close as I can get it. the most it will do is sputter for about 2 seconds and then nothing. I've tried with and without the air filter in case it wasn't getting any air but there isn't any difference. I know it runs, I had it running a year ago but couldn't get it to idle. I was going to try and sink the carbs this weekend but without it starting I can't do that. I'm at a loss at this point, an suggestions would be greatly appreciated.

[jasnmar]

Hard to know without being there. If it's "hitting" for a couple seconds, then it probably isn't timing. It may run like crap with bad timing, but if it's hitting it's usually close enough to run.

Completely guessing, if you're getting it to hit, you've verified compression, then you are running out of fuel. It takes very little air to get it to run (running is different than running well).

Is it smoking at all when trying to start? Black smoke means too much fuel. White smoke (usually) means oil in the combustion chamber (water vapor can fool you as white smoke). If you aren't getting any smoke keep adding fuel until you get some (half joking). Pour some fuel in the Carb and try it (not a lot, like start with a 1/2 tablespoon).

This is really an extreme choke. Add fuel. Remove air. Good for starting (not good for running).

[GearHd6]

Sounds like the carbs need to be cleaned to me.

[csmutty]

Clean the carbs.

[Stromper]

At least drain them

check flow from the tank petcock

get her running with starting fluid

[Uncle Snake]

Pilot jets and/or weak battery are where I'd start after draining the float bowls and gas tank and starting off with fresh fuel and 5 seconds of PRIME on the petcock.

[Rossco]

Could be a vacuum leak. This has CV carbs, yes?

[FAST GSXR750]

Clean the carbs, I know my GS650 will not run without the air cleaner installed, just keeps sputtering out. Needs the restriction.