Help!!!!!!!!again

[GTGS]

OK I have a sick bike still. Last fall I had a problem with gas leaking into the air box and out of the dump tube and it ran really rough and would load up. I cleaned the carbs and put in new O rings, re-set the floats and drilled the caps out on the idle circuit screws. It seemed to run too lean and wouldnt accelerate smoothly. After discussing it here, someone had me bypass the petcock and try it on prime. It ran better so I replaced the petcock with a new OEM part. I put it all back together today and she fired right up and ran well at idle. I took it up and down the street and it ran great (like a rocket) for a few minutes. Then I stopped at a light and it loaded up at idle Brrrrrrrrrrrr and stalled. I got it back home and I found gas leaking pretty good out of the dump tube on the floor. It has a K&N filter and the box is sealed properly. I'm really tired of dealing with this. Do I have to pull the carbs and re-clean? Everything is new. Petcock, o-rings, and rebuilt according to the process on this website. I'm at a loss.

'81 GS550L

 

[Guest]

Rust in the tank?
You got debris on the float needle and seat.

 

[gearhead13]

Well, yes you have to remove the carbs. You sound like you have leaking float valves and/or maladjusted float height. Any dirt that gets to the float valves can hold them open, causing the bowls to overflow and leak into the airbox or vent tubes, and wear on the valve can cause them to leak. If you find dirt/rust in the bowls, I would recommend getting an inline filter and/or cleaning out your gas tank.

 

[GTGS]

I did clean the tank well with acetone and I sealed it with Caswell. There shouldn't be anything in there. I had no leaks till I actually ran the bike up and down the street. At Idle, revving the engine it revs good and strong. When I set the float height, I set it on the high side of the tolerance (with the carbs upside down) so with them in the normal position they would close the needles a little earlier. Everything worked fine for a little while so I assume the needles and seats are OK but as you stated they may have gotten some debris in there that is holding them open or I have a sticky float?

 

[GTGS]

I have the 32mm? CV mikuni carbs. What are you guys setting the float height at? I used the Clymer manual and I think it said to set the height at .840 - .920". Are you setting them to the middle of that range? As I said earlier I set them higher so the needle would close earlier. Could that have caused a problem?

 

[BassCliff]

Hi,

The float height should be 22.4mm. The factory service manual (which you can download from my website) says +/- 1mm, but it's best if you get it right on, or a near as humanly possible.


Thank you for your indulgence,

BassCliff

 

[GTGS]

Thanks. Last night I tapped the sides of the float bowls and fired it up and it was fine again with no leaks. I'm hoping it was a first start up glitch. I did everything in the rebuild that was recommended (except set the float height at the mean) and until I accelerated real hard up through the gears it purred like a kitten. All I can think of is the bowls got low on fuel and as they were "catching up" one of the floats got hung up. I guess I will try to run it around the neigborhood for a while and see if it happens again. If so we'll tear it apart and start over.

 

[Nessism]

Good job on tapping the carbs to get the float to drop down. Sounds like you have done your homework. Don't forget to adjust the valves before you get to far ahead of yourself. Hate to see the bike burning valves because they were hanging open.

 

[koolaid_kid]

It is also possible that you dislodged a piece of debris that was lodged in the needle and seat. You may wish to consider a high-flow in-line fuel filter.

 

[GTGS]

It is also possible that you dislodged a piece of debris that was lodged in the needle and seat. You may wish to consider a high-flow in-line fuel filter.

Any recommendations?

 

[BassCliff]

Hi,

If you must use a fuel filter, get one designed for gravity-fed systems. Typically a lawn mower filter will do.


Thank you for your indulgence,

BassCliff

 

[GTGS]

Thanks for the ideas guys. When I got home today I took it out for a short ride and she ran like a champ. I guess I panicked. I will add a filter for good measure. I did however run into a lighting issue. Another thread I guess..Thanks for the help.