Gen 1 SV Starting/idle issue

[GingahNinjah]

So just to be clear the carbs have been opened up and cleaned now 3 times. my race bike is having an issue starting. the starter is cranking, there is spark. one interesting symptom is that when the bike is cranking there is a heavy mist of fuel coming out of the top of the front cylinder carb where the air box sits. this fuel mist also comes from the rear carb but only at first. It seemed to be getting either too much air or too much fuel or both but I dunno how to tell and not sure how to fix it. when the bike can be gotten started it doesnt idle and needs to be held around 3000 rpm to keep it running and at times it sounds like it is firing on only one cylinder. spent all day at NHMS on monday working on this problem and missed all but the last session of TTD because of it. now with a race weekend coming up I am at a loss. Chuck(Snowman) has a set of gen 1 carbs that he is gonna bring to the track with him on friday but there may be other issues going on. this being my first carbed bike in a long time and my first vtwin I am out of my element and there were a number of us at the track working on it. any thoughts or if you wanna lend a hand at the track it would be appreciated. Huge thanks to Jasnmar, NHBubba, Snowman and everyone else who threw in help trying to get the bike running for TTD

[soofle616]

Sucks that you didn't get it sorted dude. Still scratching my head about that front carb spitting gas out when the bike is running, just makes no sense to me.

[nhbubba]

Have you ruled out Mark B's suggestion? I know you don't want it to be that. I don't want it to be that. Nobody wants it to be that. But have you ruled it out?

It sucked watching you wrench-and not ride-that thing all day Monday.

[GingahNinjah]

Colin until i have completely and undeniably ruled out carb issues im not gonna go splitting cases and/or pulling heads. the bike will run. was able to getting it running for the last session of the day on monday. albiet that it wasnt running perfectly it was running. there wasnt any knocking, banging or any other noise coming from it that would suggest a bent, hungup or otherwise fucked up internal but it did seem like it wasnt quite running on both cylinders all the time. Chuck is bringing the carbs off of his Gen 1 on friday and hopefully that will fix the problem or atleast remove questionable carbs from the equation

[OreoGaborio]

Maybe the injectors are pointed the wrong way? That would explain fuel shooting upwards.

[carsick]

Way to kick a carb'd guy when he's down Pete

[jasnmar]

Replacing the carbs will at least eliminate the possibility of it being the carbs, so start there.

When you have eliminated the impossible, whatever remains, however improbable, must be the truth.

I'm also fearful that an intake valve isn't getting closed, that doesn't mean I'm right.

[Sheppo]

unless the carb's are way F'd up... I'd start looking elsewhere too. Too tight valves certainly will do this. When was the last time the valves were checked? I would try chucks carb's first, but I wouldn't hold my breath. There is also the thought of a vacuum leak.

I am shooting into the air here. I haven't seen the bike or know the symptoms except what you posted. It hard to diag stuff over the internet.

[golden chicken]

My gut reaction would be valve issues, but like Sheppo said, hard to diag over the 'net. A compression test and a leakdown test could help you narrow it down before you go tearing into it.

[GingahNinjah]

can see the intake valves operating smoothly with the carbs off and cranking the starter. tho yea it is possible that one or more may not be seating correctly... :/ talked to a local shop. gonna drop the bike off there after I get outta work. at the least they will be able to tell me if there is any damage within the motor itself...

[Kurlon]

How hard is it to get to the plugs on that motor? If they're not a total PITA I'll bring my compression tester to the track with me, that'll quickly answer a bunch of questions.

As to the hard starting and bitchy idle when cold, if you're getting reversion through the carb, the bike is trying to run on a charge of air that's been through the carb more than once, WAY too much fuel at that point. Once you do get it lit, the combustion will provide a bit of incentive for a badly seating valve to close up a bit better, so you'll reduce your reversion a bit, and the heat will help it de-foul itself as it comes up to temp.

[GingahNinjah]

plugs are easy to get to had em out repeatedly between sun and mon

[Kurlon]

Guess that's another thing to throw in the truck tonight.

Wish I had a leakdown tester, just rolling it to TDC and putting air to it would reveal a LOT.

[nhbubba]

I'll be there Friday. If there's any way I can help, lemme know.

[Sheppo]

Just cause you can see the valves operate doesn't mean theybare working correctly or seating correctly.

[cableguy]

Sounds like the float isn't floating, which means the needle isn't seating when the bowl fills up. Have you double checked the float height? Are you sure the float hinge isn't bound up somehow?