I rode the bike home, it had a handful of issues I thought a carb cleaning could fix. I pulled them apart, dipped the carbs for several hours each until they looked nice and clean, replaced a few gaskets, put everything back together, and now it's not usable.

When I first tried to start it, it wouldn't start at all, killed the battery a couple times trying. Then it finally started, but it shot up to 5k rpm and hung there, then died after about a minute. It would hang at 5k rpm with full and no choke. That was with the pilot screw at 2.5 turns out. I turned out the pilot screws to about 3.5 turns, and now it will start, rev up for a second, then go down to around 1000-1200 rpm, then die within a minute or two.

I need this bike running to get to work I've replaced a bunch of other things on it. I have no idea what the problem is. Could worn out float bowl gaskets cause a vacuum leak? I didn't replace those or the needles or seats. AFAIK, the jets are stock.

Did you sync the carbs? That would do it.

Also, did you check to make sure you put all o-rings and gaskets back in place?

I tried to visually sync the carbs when they were off. I don't want to leave the bike screaming at what is now a 6k rpm idle while trying to sync them. All the carb parts went where they should. I'm going to take out the slides and lube them with some motor oil.

So I found part of the reason it was starting was for lack of fuel. When I set the petcock to prime, it started, but still runs at 6k rpm, and gets quite hot really quick. I'm thinking a vacuum leak, but I don't have starter fluid, nor am I exactly sure of how I'd use it. I don't like to leave the bike running too long at such high rpms while just sitting there.

The throttle cable has some slack, right?  Have you backed out the idle screw?

Throttle cable has minimal slack. Maybe I did open up the idle a bit too much! I'll go try that...

Well that's embarrassing... I had the idle adjusted way too high. Idles beautifully now. My petcock only works on PRI I discovered.

However, why would it start and have no need of choke? It runs perfect from a cold start, I have no idea how it runs hot as it currently has no chain or brakes.

Quote from: BikerMedic on January 31, 2015, 06:14:10 PM
Well that's embarrassing... I had the idle adjusted way too high. Idles beautifully now. My petcock only works on PRI I discovered.

However, why would it start and have no need of choke? It runs perfect from a cold start, I have no idea how it runs hot as it currently has no chain or brakes.

Petcock only working on prime means your vacuum line isn't set up right, or you wired your fuel lines backwards.

Let it idle and get hot. I'm guessing your idle will rise considerably.

May sound silly, but I had to clean my carb twice.
The first time a real clean, the second time some rust got in and clogged the jets.
pri is not the right way of running the bike!
It won't run long anyway.

5k rpm idle sounds lik the carbs are out of sync, and a (semi) clogged jet could be the reason.

Quote from: Dr.McNinja on January 31, 2015, 11:46:57 PM

Petcock only working on prime means your vacuum line isn't set up right, or you wired your fuel lines backwards.

Let it idle and get hot. I'm guessing your idle will rise considerably.

If I hooked up the on and reserve hoses from the tank to the petcock backwards, that would cause the petcock not to work? I've got the vacuum line hooked up to the left carb in the spot where I have a vacuum cap on the right (the side, not the top). I'm sure the idle will rise when hot. Do I just need a larger pilot jet? Turn out the pilot screws more? I'm a bit confused, as the airbox and exhaust are stock. I intend to sync the carbs shortly.

Anybody know where I can find an affordable petcock rebuild kit? I have to imagine I could rebuild the thing for less than the $50 cost of a new one...

I did a so-so sync job with a bit of oil in aquarium hose, at some point I'll build something more precise. I got it so that the bike starts perfectly, idles fairly nicely (1300-1500 rpm) while somewhat warmed up (can't take it for a spin just yet), and has pretty decent throttle response, maybe just a bit lean sounding. That's with the pilot screws at 3.5 turns out.

However, if I turn on the choke while it's idling, instead of shooting up in the RPMs, it just dies. And if I set the idle closer to 1200, it sounds like it's going to die. So something sounds a bit off. Any ideas?

Quote from: BikerMedic on February 01, 2015, 11:24:34 AM
I did a so-so sync job with a bit of oil in aquarium hose, at some point I'll build something more precise. I got it so that the bike starts perfectly, idles fairly nicely (1300-1500 rpm) while somewhat warmed up (can't take it for a spin just yet), and has pretty decent throttle response, maybe just a bit lean sounding. That's with the pilot screws at 3.5 turns out.

However, if I turn on the choke while it's idling, instead of shooting up in the RPMs, it just dies. And if I set the idle closer to 1200, it sounds like it's going to die. So something sounds a bit off. Any ideas?

Choke goes up and bike dies means you're flooding the engine. I'm guessing your bikes AFR is now on the really rich side, so the choke makes it even richer once the bike is warm, and then it dies.

In regards to the starter fluid question, spray it on places where you suspect a vacuum leak. If the idle immediately shoots up, you know you have a leak.

Any silly cause is always love-hate for me - I'm glad it's solved, but I hate having to admit to it.

As for the too-easy cold start, mine was doing that too.  Make sure you set idle when it's hot, and you might also need to muck with the idle mixture screws (the evil ones); I spent an hour doing that and my bike went from running ok to running beautifully, and from first-press-cold-start-no-choke to ... what a damn carbureted engine should do when it's cold.

I can't honestly tell you where my idle mixture screws are in terms of turns out, because I forgot to measure them after I mucked.  ...Dammit, hold on, I'm going to go check...  They're at 2.5 turns out (well, 2.5 turns right, 2.625ish left), but again, that's from mucking with them, on my bike, in my climate and altitude, so YMMV.