Wouldn't start, then trouble idling

[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,...

 

[mark]

Yeah, you pretty much have to go through it all......

You can test your petcock pretty easily. Pull your vacuum line off the carb, put the petcock to "ON" and suck on the vacuum line. Gas should start flowing from your petcock. If you suck in a bunch of gas (be careful) then you'll redefine "having gas" and have something else you need to fix.

Probably started the third time when you opened the throttle because it was flooding a bit by then..........when you let in a little air it fired.

 

[UncleMike]

Yeah, you pretty much have to go through it all......

You can test your petcock pretty easily. Pull your vacuum line off the carb, put the petcock to "ON" and suck on the vacuum line. Gas should start flowing from your petcock. If you suck in a bunch of gas (be careful) then you'll redefine "having gas" and have something else you need to fix.

Probably started the third time when you opened the throttle because it was flooding a bit by then..........when you let in a little air it fired.

Okay, that makes sense.

When I pull the vacuum line, put it to "ON" and suck on the line, gas should or shouldn't flow? You say it should, but also say that if it does, I'll have something else to fix. Were you referring to a mouthful of gasoline, or would the petcock then have a faulty diaphragm.

Or is this whole thing a long-distance practical joke, with the goal of getting me to drink gas in retribution for the political/relgious threads?

 

[Billy Ricks]

Okay, that makes sense.

When I pull the vacuum line, put it to "ON" and suck on the line, gas should or shouldn't flow? You say it should, but also say that if it does, I'll have something else to fix. Were you referring to a mouthful of gasoline, or would the petcock then have a faulty diaphragm.

Or is this whole thing a long-distance practical joke, with the goal of getting me to drink gas in retribution for the political/relgious threads?

With the petcock on either run or reserve the petcock should hold vacuum when you suck on the smaller vacuum line and fuel should flow from the fuel line. If you get a little gas in your mouth while sucking the diaphram is toast. You can use a large syringe to provide sunction if you don't want to risk gas in your mouth.

 

[UncleMike]

With the petcock on either run or reserve the petcock should hold vacuum when you suck on the smaller vacuum line and fuel should flow from the fuel line. If you get a little gas in your mouth while sucking the diaphram is toast. You can use a large syringe to provide sunction if you don't want to risk gas in your mouth.

So of the two lines coming off the petcock, I can see a big one that disappears in the middle of the back of the carbs, and a small one that connects to the middle of the front. I want to pull off that smaller line and suck on it, and fuel should flow from the larger fuel line, but not into my mouth?

 

[Billy Ricks]

So of the two lines coming off the petcock, I can see a big one that disappears in the middle of the back of the carbs, and a small one that connects to the middle of the front. I want to pull off that smaller line and suck on it, and fuel should flow from the larger fuel line, but not into my mouth?

Correct. If you get fuel out of the vacuum line the diaphram is toast.

 

[flyingace]

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,...

I haven't yet heard anything that sounds like it's broken. It starts and runs with choke, and, until I hear otherwise, runs OK when warm. It almost sounds to me like an unwillingness on your part to use the choke until the bike is warmed up.

 

[UncleMike]

Correct. If you get fuel out of the vacuum line the diaphram is toast.

Okay. Now, just to be clear, when you say fuel should flow from the fuel line, what do you mean? The action of my sucking will cause fuel to flow from the tank down the other line into the carbs? Is my sucking mimicking the vacuum flow that would normally occur during operation?

Sorry I'm so slow at this, but it's a symptom of not knowing how the petcock works. I'll have to get a spare and take it apart.

 

[UncleMike]

I haven't yet heard anything that sounds like it's broken. It starts and runs with choke, and, until I hear otherwise, runs OK when warm. It almost sounds to me like an unwillingness on your part to use the choke until the bike is warmed up.

A bit, yes, but my main concern is the reluctance to start without starting fluid. Although that wasn't an issue this morn.

 

[Billy Ricks]

Okay. Now, just to be clear, when you say fuel should flow from the fuel line, what do you mean? The action of my sucking will cause fuel to flow from the tank down the other line into the carbs? Is my sucking mimicking the vacuum flow that would normally occur during operation?

Sorry I'm so slow at this, but it's a symptom of not knowing how the petcock works. I'll have to get a spare and take it apart.

The smaller line is only supposed to allow for vacuum to be applied to the diaphram in the petcock. No fuel should be present in it and it should hold vacuum if you put your tongue over the end of the vacuum line while sucking on it. Remove the fuel line to the carbs at the petcock and attach a piece of fuel line to the outlet to see if fuel runs out of it when you apply the vacuum. You can run that fuel line into a bottle or something to keep from making a mess.

 

[UncleMike]

The smaller line is only supposed to allow for vacuum to be applied to the diaphram in the petcock. No fuel should be present in it and it should hold vacuum if you put your tongue over the end of the vacuum line while sucking on it. Remove the fuel line to the carbs at the petcock and attach a piece of fuel line to the outlet to see if fuel runs out of it when you apply the vacuum. You can run that fuel line into a bottle or something to keep from making a mess.

Very interesting. Thanks!

That's 5/16 right?