I GIVE UP!! Figure this out if you dare!

[Anonymous]

I found that the problem with my bike was actually a pinch in the fuel line.

I think the gas line pinching may be a symptom causted by inadequate venting of the fuel tank. You may want to check it out anyway. One way to verify the tank venting is to take a ride with the cap loose (near empty tank). If you don't have any problems then - it's probably the venting.

 

[Planecrazy]

I will make a note to have my buddy check the fuel line as well (if the gas cap venting test doesn't pan out). Actually, Tyler, it's funny you left me this note because I just got finished leaving you the fuel vent tip in YOUR thread! LOL! :lol:

Steve 8)

 

[Anonymous]

Another thing that can happen is that the needle shut-off valve into the carby can be slightly clogged or bent and when it heats up it jams shut, when it cools down it is loose enough for the spring pressure to open it.

This happened to my GS1000G a year or so ago, caused a few hours of mechanic's time trying to find what was showing up as the hot-coil symptom.

Kim

 

[Planecrazy]

I would tend to doubt that this is my problem, only because I've had the problem almost the entire 15 years I've owned the bike, and the carbs have been rebuilt several times during that period...

Steve 8)

 

[nert]

[In both instances, it happened much more easily in hot weather (because pressure builds up much more quickly on a hot day). ]

That doesn't fit with the moral of the story!. Heat by your statement makes more pressure more rapidly. Pressurizing the fuel. It sounds like everyone is suggesting vacuum, or a negative pressure restricting the fuel. Hot weather may be affecting something else?[/quote]

 

[jimcor]

The problem is the petcock. Non-rebuildable 69 bucks about 8 years ago. I had the identical problem with my '80 550L.

 

[Planecrazy]

[In both instances, it happened much more easily in hot weather (because pressure builds up much more quickly on a hot day). ]

That doesn't fit with the moral of the story!. Heat by your statement makes more pressure more rapidly. Pressurizing the fuel. It sounds like everyone is suggesting vacuum, or a negative pressure restricting the fuel. Hot weather may be affecting something else?

[/quote]

The reason they're all suggesting vacuum (and why it makes sense) is that the engine at high rpms (on the highway) is drawing fuel into the engine faster than it's expanding in the tank as vapor. Normally the fuel vent would allow air to enter the tank and fill the void, but if the vent is clogged because the old material is expanding in the heat, a vacuum would be created in the tank that would starve the engine of fuel flow.

We haven't had a chance to test this theory yet, because it's been storming here for days now, but as soon as we get a chance we'll let you all know what we find... I sent Jimcor a reply to a PM addressing the petcock suggestion. I'll keep it in mind, but I think a bad petcock would be bad regardless of temperature ... mine works fine when it's cold out.

Regards,
Steve 8)

 

[nert]

I understand the fuel starvation theory. I have no opinion on the cause of this GS problem. More information needs to be obtained, more tests performed.
I am pointing out that an individual replied and offered the argument of heat/hot day makes the situation worse because excessive/accelerated pressure build up in the fuel tank more rapidly on a hot day.
The prevailing thought through out the messages was fuel starvation.
May be it is the cause, maybe its not.
I am just pointing out that, positive pressure in the tank won't make a fuel starvation situation worse and IS NOT a valid argument to support the theory of fuel starvation on a hot day. Just the contrary!!!

 

[Planecrazy]

I understand the fuel starvation theory. I have no opinion on the cause of this GS problem. More information needs to be obtained, more tests performed.
I am pointing out that an individual replied and offered the argument of heat/hot day makes the situation worse because excessive/accelerated pressure build up in the fuel tank more rapidly on a hot day.
The prevailing thought through out the messages was fuel starvation.
May be it is the cause, maybe its not.
I am just pointing out that, positive pressure in the tank won't make a fuel starvation situation worse and IS NOT a valid argument to support the theory of fuel starvation on a hot day. Just the contrary!!!

Sorry Nert, when I read your post it looked like you were the one talking about a buildup in pressure because you didn't attribute the prior quote to anyone else (Chuckycheese) and I didn't remember seeing it. I went back and re-read his quote ... looks like he was describing a vacuum situation everywhere except in that one sentence, so I think maybe he meant to imply something other than how it came out just then ... anyway, thanks for the input!

Steve 8)

 

[Planecrazy]

Hi All,

Well, finally, we had a chance (and good weather) to reproduce the problem and check the gas cap for proper venting! Turns out that the fuel vent is NOT the problem, as the bike still refused to run properly after lifting the cap (and there was no telltale whoosh).

I'm now leaning toward a suspect petcock, based on some of the prior posts. Looks like I'll be ordering a Pingel this week and we'll see if that doesn't solve our problem. At least when I sell this bike (soon) I'll be able to say that almost every known Suzuki GS issue has been addressed with proper replacement parts... Damn this is frustrating!!

Steve :evil:

 

[Anonymous]

save the buck

save the buck

Be sure before you spend all that money if you take it out and run it and it quits open the float bowl screw up and see if a full bowl of gas comes out, if it does you have another problem

 

[Planecrazy]

Good Idea ... Thanks!

Steve 8)

 

[robinjo]

Found it yet?

 

[Anonymous]

Found it yet?

I find that statement amusing when coupled with your avitar. :lol:

 

[Planecrazy]

Found it yet?

I find that statement amusing when coupled with your avitar. :lol:

LMAO! :lol:

Not yet ... It's challenging when the bike is in my friend's possession and I can't just take it out and try "the next thing." He has two weeks off starting Friday, so I hope to move forward more quickly in nailing this problem down. I will let you know as soon as I do, though!

Thanks,
Steve 8)