Sputtering

[bjrscj]

I recently had issues with my bike starting up, which seem to be resolved (viewtopic.php?f=7&t=5306&p=58730#p58730). However, it seems a new problem has arisen, but it may be tied to my old issue. I'm posting it here since it should be categorized differently.

Now it seems that my bike will start when the petcock is at prime, and with choke all the way up. After warming up, however, I still have to keep my choke at about 1/6, and if I move the petcock to normal position, my engine stalls and dies - even after VERY warm. I realize that my idle speed should probably be bumped up, but it should still run without being in the prime position. I took about an hour drive today, and after about 45 minutes, I turned the petcock from prime to normal at about 55 mph. The bike ran for about 30-60 seconds, then stalled and died. On top of that, it seems a little jerky even when riding in prime position.

I was worried that my start up problem was either due to old gas or a flooded engine. Someone mentioned that the flooding may have gotten gas into the oil. The oil in the window looks coffee color, and it looks like I have enough. I'd appreciate any insight you may have. Thanks!

[blaine]

I sounds like the petcock may be partially plugged.You need to take the petcock out and check that the screens are free from dirt.
:cool:

[Gz Rider]

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[alantf]

I've read the answers above, but it seems to me that the problem lies with the vacuum pipe to the petcock. In prime, fuel flows freely, but run requires engine vacuum to open the valve. If the pipe has come adrift, or is damaged, it will definitely give the symptoms you describe. I would definitely check the vacuum pipe before stripping the petcock.

[blaine]

Originally Posted by alantf

I've read the answers above, but it seems to me that the problem lies with the vacuum pipe to the petcock. In prime, fuel flows freely, but run requires engine vacuum to open the valve. If the pipe has come adrift, or is damaged, it will definitely give the symptoms you describe. I would definitely check the vacuum pipe before stripping the petcock.

You are right,Alan.I totally forgot about that because my current bike has no "pri" position.Thanks for the reminder.
:2tup:

[Gz Rider]

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[Meme]

Yes, if the vacuum line is off of the petcock you will not have "ON" or "RES" and it will run lean because it is sucking air. That would cause it to need the choke on to have the right fuel/air mixture.

[bjrscj]

I read the alternate topic and will give that a shot if I can rule out the vacuum pipe. Just to clarify, I'm looking for any instability in the pipe (movement)? Also, if I run the bike on prime in the meantime, would that potentially cause any problems? Thanks!

[alantf]

Originally Posted by bjrscj

I'm looking for any instability in the pipe (movement)?

What you're looking for is a loose connection to any nipples, damage or cracking of the pipe - in short, anything that could cause a loss of vacuum in the pipe. Vacuum is needed to open the valve, so anything that lets air into the pipe is a problem. I still think that this is your problem, & will do so until you assure us that the pipe is undamaged. :2tup:

[Gz Rider]

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