'83 GS1100GL backfire/idle problems

[cozee]

Recently picked up an '83 GS1100Gl. This bike has set for a few years till the guy I got it from had gotten it ladst year. He had gotten it running but do to some titling red tape and lack of patience, he let it set. After I got it home. I did a quick clean of the carbs and but in a new battery. It starts and runs well. Idle is somewhat rough and at times up and down slightly. While riding if I back off the throttle, I get some backfiring, sometimes really sharp and most of the time out the left side. I did notice when taking it apart for the carb cleaning that the foam seal on the air cleaner was about non-existent. Also, a couple of the carbs (right 2) really had some gunk in the mains with one having been plugged completely. Plugs look passible for normal.


Could this be simply the air cleaner or should I tear the carbs down for a rebuild? I've got a bit of time as I am awaiting the completion of the paper work for the title.

Thanks!!

 

[cozee]

Anyone? Don't let me down now!

 

[mixongw]

Mine had the same problems. The air cleaner foam seal can be replaced using weather sealer from the hardware store. As for the carbs, my problems were mainly in the pilot circuits. The pilot jets have a small hole in the bottom that I overlooked the first time I had them apart. After cleaning them again, all was well and still is. Mine does sound like a popcorn popper when I close the throttle going down a hill. I thought it was normal.

 

[cozee]

Weather strip foam, I should of thought of that! The filter looks new but as I said, the foam is toast. I'll try that but I beleive I am simply going to do the carbs right and then rest easier about them.

 

[bwringer]

Your symptoms could be due to the airbox seals, but it sounds like more than that. With any bike of unknown history, you almost certainly need intake boot o-rings. Make sure you thoroughly check the intake boots, too.
http://bwringer.com/gs/intakeorings.html
"Macmatic", one of the users on this site, sells the o-rings cheap, but they're still very cheap if you just order them from your local Suzuki shoppe.

And yes, anything but surgical cleanliness in the carbs means you need to take them off and clean them thoroughly. Try not to use the expensive low-quality junk in most rebuild kits -- usually all you need is just a set of o-rings and some float bowl gaskets, and then clean and re-use the original brass. Make sure float height is correct -- it makes a big difference if it's off by 1/2mm. Unless the needles and seats have been replaced, it's probably OK, but you never know what previous owners have done.
O-ring sets:
http://cycleorings.com/

You can get float bowl gaskets from CRC2 in Indy:
http://crc2onlinecatalog.com/

 

[cozee]

Thanks for the links, and especially the info on the o-rings. Was about to buy kits for em since the hardware looks good and not needing replacement. I don't have a manual for this bike yet. What should the float level be set at?