Gas in airbox

[don]

Hi chef,

The needles, or the needles, the jet tubes and the jets? And can you be sure? The bike ran great for like 1-1/2 seasons as is, then started running like crap over like a week or so then more rapidly. Don't mean to be a jerk, just wat to be sure. Made a lot of changes so far on the premmis, " what the heck else coud it be" to find out "none of the above".

Again, I really don't want to sound like a pin head. Just looking for some help with a problem that does not fall into the catagory of the usual cures. Both sets of carbs that I have are in pretty good shape from what I've seen. And I have access to ultrasonic cleaners etc. Just trying to get some help with an unusual problem from the experts.

 

[Guest]

Hi chef,

The needles, or the needles, the jet tubes and the jets? And can you be sure? The bike ran great for like 1-1/2 seasons as is, then started running like crap over like a week or so then more rapidly. Don't mean to be a jerk, just wat to be sure. Made a lot of changes so far on the premmis, " what the heck else coud it be" to find out "none of the above".

Again, I really don't want to sound like a pin head. Just looking for some help with a problem that does not fall into the catagory of the usual cures. Both sets of carbs that I have are in pretty good shape from what I've seen. And I have access to ultrasonic cleaners etc. Just trying to get some help with an unusual problem from the experts.

The emulsion tubes (needle jets) can oval out and allow gas by the jet needle. The needle can also wear out but I haven't personally seen this.

 

[don]

I guess I'll try that, no other normal stuff has worked so far. Good thinking.

 

[don]

OK fellas, here we go,

First off I have to apologize to all I may have offended by contesting their suggestions. Second, I humbly bow to the GS gods of this site.

Now that that's over, the winning answer is ................. the valve on the tank. If someone had told me the following, I would have taken it with a grain of salt and went on my way. I wouldn't have believed it if I hadn't seen it myself.

I made sight glasses for the bowls so I could see what the fuel height was when the carbs were overflowing. If the fuel level was up when they were overflowing then I would know to look at the fuel delivery, if the fuel level was good when the carbs overflowed then I could eliminate the fuel delivery.

I started the bike and let it warm up. I hear it sounding a little ritch and the fuel level was indeed higher than when I started. I don't even know why I decided to do this, but I turned the fuel valve to PRI. When I did that, the fuel level returned to it's original height. I turned the valve back to the RUN position, and the fuel level started to rise again. To take what I had seen one step further, I removed the tank and put on my 1qt bottle that I use when I run the bike to tune it. I ran a whole quart of gas through it while monitoring the fuel height. The fuel level never changed. I pinched the fuel line off to stop the fuel flow and let the fuel level drop then let it go to see if the level returned to the same place of if it would "wander". It stopped at the same place every time.

I have taken a couple of short rides (40-50 miles) with the valve in the PRI position with no issues. I have put it in the RUN position a couple of times to see if it would act up, and sure enough, it does.


Once again, thank you all for all of the suggestions and help. I am truly grateful for it.

Don

 

[81gs1100]

I read earlier in you rposts that you turned the petcock on "pri" and the problem stopped, then rebuilt the petcock and the problem came back when on the "on" position? This is the first time reading the thread, but I thought you had it solved many posts ago about the petcock, but you seemed to have set it aside as not the problem?

Im just glad its working for you now, the question I have is what did you do to give yourself "site-glasses" to the floats?

 

[don]

Up to now, I only had quickie sights that couldn't be used while riding so I couldn't ride a little, ..... look, .... ride some more, .... look some more. The other problem was it wouldn't act up every single time I rode it. Sometimes I'd get lucky and it would be fine.

I honestly have no idea why I've been through the same cycles of repairs other than I didn't do them correct the first time.

Anyway, I have 3 racks of carbs so I have extra parts. To make the correct bowl sights I simply drilled and tapped the drain screw for the bowls and screwed a 10-32 elbow and barb fitting into it. The actual sight "glass" is just some clear tubing. Works great.

 

[81gs1100]

Ahhh, see. So pretty much making a float level gauge. I was looking for something on the lines of a permanent viewing of the fuel levels.

I know for the Lectrons they make plastic float bowls that you can see the fuel level through.