RE: 1980 GS 1100 16 vakve Carbs Leaking out vent tubes

[chewbacca5000]

RE: 1980 GS 1100 16 vakve Carbs Leaking out vent tubes

I have a GS1100 that against all odds have brought back from the dead. It had mud and crap all over it when I got it and the PO filled the cylinders with ATF which shot everywhere after pulling the plugs. #3 Exhaust had broken exhaust bolt that I re-tapped and still needs a heli coil or weld/ retap in other hole. New exhaust gaskets and hardware.

Got all the sludge out of the crankcase, new oil pan gasket along with new generator gasket. Had to replace starter as water got in there.

New petcock and found out I have pin hole in tank. Prime position does not pour gas out like I think it should? This bike is really fighting me! New oil, new filter.

Now carbs are back together adjusted floats to 22.4 as I read here. 2 1/2 turns on air / mix screws. O-rings on needle valve are sketchy at best on all 4 carbs. Needles and seat are in fair condition, but they leak out the vent tubes! Also looks like they are leaking out of some jets on the air box side? Never seen this one before.

Any help to get this thing to stop leaking would be appreciated! Thanks in advance.


Edit: Solved. The problem was that I accidentally bent the jet retainer clip and the floats were hanging up. Bending it back solved the problem.

 

[rwnielsen]

"needles and seats are in fair condition"
Those need to seal, completely, or you'll have overflow and leakage

 

[chewbacca5000]

Much Thanks! Can you recommend a good source for these? I will put in my order now. Was considering partsnmore.com

Also, where do I take the float height measure measurement from?

Found a great carb rebuild guild for BS32, BS34, and BS36 carbs if anyone needs it.

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

 

[JayWB]

1980 GS550 petcocks are pretty strange, and I think the same strangeness applies to all other models that year as well.

Even in "Prime" you have to apply vacuum to the vacuum line before any fuel will flow. The difference is that in "Prime" even after the vacuum goes away the fuel will continue indefinitely until moved off "Prime" or until the tank is empty.

 

[chewbacca5000]

1980 GS550 petcocks are pretty strange, and I think the same strangeness applies to all other models that year as well.

Even in "Prime" you have to apply vacuum to the vacuum line before any fuel will flow. The difference is that in "Prime" even after the vacuum goes away the fuel will continue indefinitely until moved off "Prime" or until the tank is empty.

Thanks for the great info. Good to know. Can these bikes be converted to a normal On / Off petcock using the BS34 carbs?

 

[chewbacca5000]

Much Thanks! Can you recommend a good source for these? I will put in my order now. Was considering partsnmore.com

Also, where do I take the float height measure measurement from?

Found a great carb rebuild guild for BS32, BS34, and BS36 carbs if anyone needs it.

http://www.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

Other than having good needles & seats with proper float height is there anything else in the BS34 carbs that can cause an overflow situation? Thanks!

 

[Spyderman]

the tutorial that you posted is from Basscliff's website he is a well known GSer and take a look at his site it has everything you need for just about any repair you could want to do to your GS
http://members.dslextreme.com/users/bikecliff/

 

[chewbacca5000]

the tutorial that you posted is from Basscliff's website he is a well known GSer and take a look at his site it has everything you need for just about any repair you could want to do to your GS
http://members.dslextreme.com/users/bikecliff/

Thank You this is most helpful

 

[chewbacca5000]

Solved! I must of accidentally bent the jet retainer clip / spring when taking the seat out to clean it. The float was getting hung up on the jet reatiner clip / spring so the fuel just kept flowing. Thanks for all the help. Hope this helps someone else.

All four carbs were dumping fuel and this was the cause not the needles.

 

[Spyderman]

ok so you had all 4 carbs dumping fuel you need to change your oil because it has been contaminated with gas which has thinned it out

 

[chewbacca5000]

No smell of gas in oil, and it is not all thinned out and watery the way oil gets when it is contaminated. Thanks looking out for me much appreciated.

 

[Guest]

Jet retainer clip? You talking about the main jet in the middle? The only retainer inside the carb is for the needle and seat portion. You going to need a o-ring kit from Robert Barr cycleorings.com gotta have these if you are going to clean the carbs RIGHT. Probably need to new rubber carb boots front and rear. Fair condition for the needle and seat isn't something I would trust, they need to be in excellent condition. If you had any gas reach the carb throats and trickle into any one of the cylinders and sat for a bit, you can count on gas in the oil. As for a replacement for the "dreaded 80 vacuum petcock" kind of iffy, Pingale may have something though pricey. Most of us just buy a new OEM petcock. As you can see, there is very little extra room between the bottom of the petcock and the chrome piece on top of the air box and the mounting on the tank is an odd size to other GSes it is a 52 mm where the others are 42 or so.

 

[chewbacca5000]

Jet retainer clip? You talking about the main jet in the middle? The only retainer inside the carb is for the needle and seat portion. You going to need a o-ring kit from Robert Barr cycleorings.com gotta have these if you are going to clean the carbs RIGHT. Probably need to new rubber carb boots front and rear. Fair condition for the needle and seat isn't something I would trust, they need to be in excellent condition. If you had any gas reach the carb throats and trickle into any one of the cylinders and sat for a bit, you can count on gas in the oil. As for a replacement for the "dreaded 80 vacuum petcock" kind of iffy, Pingale may have something though pricey. Most of us just buy a new OEM petcock. As you can see, there is very little extra room between the bottom of the petcock and the chrome piece on top of the air box and the mounting on the tank is an odd size to other GSes it is a 52 mm where the others are 42 or so.

Thanks Mr Bill,

Think I am going to put this project on hold for a few days until new needles arrive, and yes was talking about the needle seat clip. It got bent and the float would not close. Don't think I am going to get anywhere without those needles. Springs in needles are a bit weak as the float tang depresses the spring.

I was able to get it adjusted so it fires on all 4 at idle with even heat across all 4 pipes, but stalls out when you give it throttle. I will pick this up when I get the needles. Can't go any further without them.

 

[Katarat]

I have a Pingel on mine, you just need the adaptor plate for it

 

[Guest]

Thanks Mr Bill,

Think I am going to put this project on hold for a few days until new needles arrive, and yes was talking about the needle seat clip. It got bent and the float would not close. Don't think I am going to get anywhere without those needles. Springs in needles are a bit weak as the float tang depresses the spring.

I was able to get it adjusted so it fires on all 4 at idle with even heat across all 4 pipes, but stalls out when you give it throttle. I will pick this up when I get the needles. Can't go any further without them.

Okay got'cha on the retainer. Aren't you replacing the seats as well? "stalls out when you give it throttle" do you have the air box and air cleaner installed? If not, there is no way you're going to get it to throttle up. You might get 2,500 rpm out of it. It's gotta have that air restriction.

 

[Guest]

I have a Pingel on mine, you just need the adaptor plate for it

Won't work on his bike, no room for a Pingel with an adaptor plate. He would have to raise the tank quite a bit to make it work, then that is gonna cause some problems. Telling ya, it's tight fit right there.

 

[KatManDo]

Thanks for the great info. Good to know. Can these bikes be converted to a normal On / Off petcock using the BS34 carbs?

Hey Chewbacca5000, was just reading through this post and although I see that you edited it about a week ago and have now fixed your problem I thought I'd answer one of your questions regarding converting the petcock to a simple ON/OFF device. The answer is "yes" you can. I just did this very job to the petcock on my 1000 Kat. You will need to completely dismantle the petcock. The 4 screws on the back where the vacuum line is will need to be removed to access the diaphragm and shut-off plunger. Remove the complete innards and replace the cover making sure you seal it against fuel leakage by applying a good quality fuel resistant sealer. Next, find a way to plug the vacuum connector on the petcock. I tapped with a M5 tap and put a very short machine screw inside with some sealer. I can now attach the vacuum line from the carbs and not negatively affect how they work. Next remove the actual petcock lever by un-clipping the metal retaining cover ( the one that says ON/RES/Prime) and then pull out the plastic fuel diverter. There are two holes in it. One that selects ON or RES depending on the lever position and the other hole at 180 deg is for the prime. (FYI, the prime position does not need a vacuum to operate. The whole point is to fill the bowls before hitting the starter button ). Behind the diverter is a brass coiled actuator. Pull it out with needle nose pliers and chuck it in the bin. The object here is to turn the PRIME position into an OFF position. Therefore you need to find a way to block off that hole. I used my M5 tap and threaded the hole and screwed in another M5 machine screw. Very short of course, and once in position gently shaped any protrusions with a fine file to match exactly the contour of the conical profile of the diverter. Once I was happy I refitted everything, tried it out to ensure smooth operation and that the there were no leaks through my blocked off hole and hey presto one ON/RES/OFF petcock. Works like a charm and all I need do now is to remember to turn the fuel off at the end of the day's ride. Simple and effective.

 

[Spyderman]

Hey Chewbacca5000, was just reading through this post and although I see that you edited it about a week ago and have now fixed your problem I thought I'd answer one of your questions regarding converting the petcock to a simple ON/OFF device. The answer is "yes" you can. I just did this very job to the petcock on my 1000 Kat. You will need to completely dismantle the petcock. The 4 screws on the back where the vacuum line is will need to be removed to access the diaphragm and shut-off plunger. Remove the complete innards and replace the cover making sure you seal it against fuel leakage by applying a good quality fuel resistant sealer. Next, find a way to plug the vacuum connector on the petcock. I tapped with a M5 tap and put a very short machine screw inside with some sealer. I can now attach the vacuum line from the carbs and not negatively affect how they work. Next remove the actual petcock lever by un-clipping the metal retaining cover ( the one that says ON/RES/Prime) and then pull out the plastic fuel diverter. There are two holes in it. One that selects ON or RES depending on the lever position and the other hole at 180 deg is for the prime. (FYI, the prime position does not need a vacuum to operate. The whole point is to fill the bowls before hitting the starter button ). Behind the diverter is a brass coiled actuator. Pull it out with needle nose pliers and chuck it in the bin. The object here is to turn the PRIME position into an OFF position. Therefore you need to find a way to block off that hole. I used my M5 tap and threaded the hole and screwed in another M5 machine screw. Very short of course, and once in position gently shaped any protrusions with a fine file to match exactly the contour of the conical profile of the diverter. Once I was happy I refitted everything, tried it out to ensure smooth operation and that the there were no leaks through my blocked off hole and hey presto one ON/RES/OFF petcock. Works like a charm and all I need do now is to remember to turn the fuel off at the end of the day's ride. Simple and effective.

pictures of how you did this along with a detailed set of instructions (like the carb cleaning tutorial)
would be a good thing to do so that others can do this if they want

 

[Guest]

Hey Chewbacca5000, was just reading through this post and although I see that you edited it about a week ago and have now fixed your problem I thought I'd answer one of your questions regarding converting the petcock to a simple ON/OFF device. The answer is "yes" you can. I just did this very job to the petcock on my 1000 Kat. You will need to completely dismantle the petcock. The 4 screws on the back where the vacuum line is will need to be removed to access the diaphragm and shut-off plunger. Remove the complete innards and replace the cover making sure you seal it against fuel leakage by applying a good quality fuel resistant sealer. Next, find a way to plug the vacuum connector on the petcock. I tapped with a M5 tap and put a very short machine screw inside with some sealer. I can now attach the vacuum line from the carbs and not negatively affect how they work. Next remove the actual petcock lever by un-clipping the metal retaining cover ( the one that says ON/RES/Prime) and then pull out the plastic fuel diverter. There are two holes in it. One that selects ON or RES depending on the lever position and the other hole at 180 deg is for the prime. (FYI, the prime position does not need a vacuum to operate. The whole point is to fill the bowls before hitting the starter button ). Behind the diverter is a brass coiled actuator. Pull it out with needle nose pliers and chuck it in the bin. The object here is to turn the PRIME position into an OFF position. Therefore you need to find a way to block off that hole. I used my M5 tap and threaded the hole and screwed in another M5 machine screw. Very short of course, and once in position gently shaped any protrusions with a fine file to match exactly the contour of the conical profile of the diverter. Once I was happy I refitted everything, tried it out to ensure smooth operation and that the there were no leaks through my blocked off hole and hey presto one ON/RES/OFF petcock. Works like a charm and all I need do now is to remember to turn the fuel off at the end of the day's ride. Simple and effective.

His petcock is different then yours. Look at the parts fiche, his petcock is #1 unit(no lever). not the #3(with lever) they also show of which I do not know why and for some odd reason for the 81 GS1100E the only show the #3. There is no difference between the 80 and 81 models. Same thing for the 750E. I've tried fitting the #3 once no go. So, not sure your conversion would work for him.

 

[KatManDo]

His petcock is different then yours. Look at the parts fiche, his petcock is #1 unit(no lever). not the #3(with lever) they also show of which I do not know why and for some odd reason for the 81 GS1100E the only show the #3. There is no difference between the 80 and 81 models. Same thing for the 750E. I've tried fitting the #3 once no go. So, not sure your conversion would work for him.

Oops !! and there I was thinking I was going to blind everyone with my knowledge :heart-borken:

Thanks for pointing out my error. For those of us with the kind of petcock I was describing (the one with the lever) doing this conversion is easy and very effective. I hope at least a few people will benefit from my enthusiasm to shine !!

Great site. A pleasure to be part of the community :tears_of_joy: