Wouldn't start, then trouble idling

[flyingace]

It occurs to me though, that none of this solves the problem of it not starting without starting fluid,...

Oh... I thought that was a one-time thing. Now I'm more inclined to go along with the fuel starvation theories.

I would still do the fully warm idle test, but needing starter fluid each time you start indicates something more sinister. I'll ask you this question: Do you crank the throttle with the choke on? If you do, stop doing that. It defeats the purpose of the choke.

[UncleMike]

Oh... I thought that was a one-time thing. Now I'm more inclined to go along with the fuel starvation theories.

I would still do the fully warm idle test, but needing starter fluid each time you start indicates something more sinister. I'll ask you this question: Do you crank the throttle with the choke on? If you do, stop doing that. It defeats the purpose of the choke.

I do, but only because I'm trying to get the choke off as quickly as possible. It's not really "cranking" but more like holding it at a small degree of rotation. I don't have to, however, if I kept the choke on at a reasonable level.

Now, I had the drain plugs off and the petcock at Prime last night, and all four were flowing. Doesn't that mean that the petcock isn't blocked, or could it still be blocked in On?

[mark]

What makes the gas flow when the petcock is on "on" is vacuum created when the motor starts. There is a smaller line that goes from your petcock to somewhere on the carb. That's your vacuum line. So its possible to get fuel flow on "Prime" but not "on". Prime just gets around all that.

The only thing I can think of that would keep your bike from starting when cold, if when its warm it runs fine is that the choke isn't fully open somehow. You could check and see if your cable fully opens the choke when you use it. Usually you can just reach in there and open the choke by hand to check it. Other than gunked up carbs I can't think of anything else.

Also, flyingrace is right about the choke throttle thing. Opening the throttle when you're using the choke makes the choke ineffective (non-effective).

[UncleMike]

What makes the gas flow when the petcock is on "on" is vacuum created when the motor starts. There is a smaller line that goes from your petcock to somewhere on the carb. That's your vacuum line. Prime just gets around all that.

The only thing I can think of that would keep your bike from starting when cold, if when its warm it runs fine is that the choke isn't fully open somehow. You could check and see if your cable fully opens the choke when you use it. Usually you can just reach in there and open the choke by hand to check it.

Also, flyingrace is right about the choke throttle thing. Opening the throttle when you're using the choke makes the choke ineffective (non-effective).

Well, now I'm thoroughly confused. I guess the diaphragm could be bad though and prevent gas flow while in the ON position. I've never attempted starting it when warm, since I got it in late Oct., but the PO said that he needed to use starting fluid when it had sat for a couple of days.

I'll start it tomorrow and use the choke properly and give you a full report.

Thanks guys,...I appreciate it more than you know.

Mike

[UncleMike]

Although,...the bike won't start initially, without giving it a little goose with the throttle at least, but once it's started, I don't need to throttle it if I have the choke on.

[flyingace]

What Mark and I mean is to leave the throttle closed when initially hitting the starter button with the choke on. The choke is a special carb circuit designed to start the bike with a very rich mixture. Having the throttle open allows more air into the mix, therefore reducing the amount of gas and the effectiveness of the choke.

Once the bike is actually running, you can crank the throttle as much as you want.

[UncleMike]

What Mark and I mean is to leave the throttle closed when initially hitting the starter button with the choke on. The choke is a special carb circuit designed to start the bike with a very rich mixture. Having the throttle open allows more air into the mix, therefore reducing the amount of gas and the effectiveness of the choke.

Once the bike is actually running, you can crank the throttle as much as you want.

I'm pretty sure the bike wouldn't start without some throttle and choke, but if I understand what you're saying, I could achieve the same effect as full choke and a little throttle with just less choke.

[mark]

I'm pretty sure the bike wouldn't start without some throttle and choke....

Choke only to start the bike....no throttle. That's the way its supposed to be anyway. Our bikes are different, different style carbs, the starting procedure is the same I think. Mine needs full choke to start, then once it starts, I have to push the choke in a bit or it revs through the roof......

[UncleMike]

Choke only to start the bike....no throttle. That's the way its supposed to be anyway. Our bikes are different, different style carbs, the starting procedure is the same I think. Mine needs full choke to start, then once it starts, I have to push the choke in a bit or it revs through the roof......

Okay. Got it. I'll let you know how it goes today.

[UncleMike]

Okay, just got her out to start her.

First start - On Prime, full choke. Started right up. Almost immediate. Tried pulling the choke down a bit, and putting the petcock to ON and I was a little overzealous and stalled out.

Second start - Petcock to ON, full choke. Doesn't start right up, but does catch after I put the petcock back to Prime and let her crank a few times. Stalls when I'm messing with the choke.

Third start - Petcock to Prime, full choke. Won't start, just keeps almost catching. I goosed the throttle just a little bit, and she roared right up.

When she was idling, at aroud 4000rpms with the choke on full, I'd bring the choke down to try and get her to idle a little with a little more civility. If I got them down too low, where she was threatening to stall out, I'd put more choke on, but it wouldn't seem to help in time, so I'd goose the throttle, and she'd immediately start idling at ~3-4000rpms, depending on where the choke was.

No starting fluid needed today, though. And it's damned cold here, too.

From this, I'm thinking I've either got a vacuum line problem, or the pilot jets are a little plugged. Am I close?

[Billy Ricks]

I think you need to bite the bullet and strip and clean the carbs Mike. Replace o-rings and check for leaks at the manifold.

[UncleMike]

I think you need to bite the bullet and strip and clean the carbs Mike. Replace o-rings and check for leaks at the manifold.

Shhhhhh. (Yeah, I know.)

I realize that's a possibility, but I just want to make sure that's the problem before I do it. I'd hate to go through all that, and find out it's something else, you know? Plus, it's acting 100% better than it was last fall, I'm hoping due to the Berryman's cleaning out the carbs a bit.

[Billy Ricks]

Shhhhhh. (Yeah, I know.)

I realize that's a possibility, but I just want to make sure that's the problem before I do it. I'd hate to go through all that, and find out it's something else, you know? Plus, it's acting 100% better than it was last fall, I'm hoping due to the Berryman's cleaning out the carbs a bit.

Keep trying the fuel additive for a few more tanks, it may do the job. Chevron's cleaner with Techroline or Sea-Foam are reputed to be about the best. Berryman's is good stuff too, I've used it alot in vehicles over the years. Try spraying a little WD-40 around the intakes and see if the engine speed changes to check for intake leaks. Of course the bike has to be running to do it.

[UncleMike]

Keep trying the fuel additive for a few more tanks, it may do the job. Chevron's cleaner with Techroline or Sea-Foam are reputed to be about the best. Berryman's is good stuff too, I've used it alot in vehicles over the years. Try spraying a little WD-40 around the intakes and see if the engine speed changes to check for intake leaks. Of course the bike has to be running to do it.

I've got some of the Chevron. Ran it in a tank last fall. It'll be my next tankful.

I'll try the WD-40 next. Although I think I tried it with misting water last year and nothing happened.

Thanks guys. Be clueless without you all.

Mike

[UncleMike]

This is probably gonna sound stupid, but I guess I'm just trying to eliminate the possibility that it could be a problem with the petcock, or that the valves need adjusting, or something electrical, before I tear apart the carbs. I'm so ignorant when it comes to this, that I don't even know if any of those are possibilities. Thinking it's time to adjust the valves anyway,...