1980 GS450S Surging

[Tangmere]

Well, I will start of as all Noobs do and apologize for my post to begin with :-D

I have searched for this topic and have had no luck, but may be wording this incorrectly. I have found surging issues with bikes at higher rpm's, but mine is surging at low rpm's and runs fine after about 5500 r's. I originally thought points were the culprit, but found out pretty fast, no points on this here GS. So, that said, I understand that a vaccume issue may be at hand, but I have read that that only happens at higher rpm? I need to pull the carbs and check float levels, and probably do the silicone sealant inside the boots as I have read as well. The surging at low rpms is just a mystery for me, as at higher r's the weighted points would advance and open the points earlier or wider to help the issue, but that is exactly what it is feeling like.

Any help would be greatly appreciated! Its a really neat little sport, I have actually come to enjoy this little guy even though I have larger steeds in the barn.

Thanks! 8)

[Nessism]

My guess is that the carbs are dirty and/or you have vacuume leaks. Tons of info about cleaning the carbs and replacing the carb O-rings. Also change the large O-rings between the rubber carb isolators and the head - do NOT use silicone sealer on the rubber isolators, replace them if cracked and ALWAYS replace the large O-rings!

[Dave8338]

My guess is that the carbs are dirty and/or you have vacuume leaks. Tons of info about cleaning the carbs and replacing the carb O-rings. Also change the large O-rings between the rubber carb isolators and the head - do NOT use silicone sealer on the rubber isolators, replace them if cracked and ALWAYS replace the large O-rings!

Listen to Nessim here!!! No silicone allowed! Also, as you explain your low RPM surge, and a good upper midrange to WOT (the main jets step in here and over ride the needle jet settings), it is a safe bet that you are in for the "babtisim by fire" read LEAN, issue. O-rings on the head between the boots and the head itself, all connections between the boots/carbs, carbs and the air box, and the air box itself, including the filter. Check them all! Some say WD-40, I use starting fluid. If you choose the WD-40, you can expect your RPMs to drop when sprayed (if there is a leak). Go the either route and your RPMs will increase with a leak. Do this test first...then let us know.

[Tangmere]

Gotcha. I had read that a thin swipe of silicon inside the boots was an economical method to replacing the boots. I will NOT be doing this as the last to replys have pointed away from that remedy. I will check the starting fluid method when i get home. This bike was setting for about 15 years. I kind of rescued it from a buddys garage. Its in GREAT shape, and is close to really running good. I have only put just over 1 tank of gas through it since taking everything apart and just cleaning things. It does have new plugs and oil, fuel filters, and petcock, but everything else is bone stock equipment. He actually did run it out of fuel before he parked it 15 years ago, and the carbs, as well as the inside of the tank, looked really good. I have done the barn find thing on some older Hondas and have found completely varnished carbs in the past, and this one was spectacular. 8000 miles on the clicker. Medium Burgandy. Good looking little bike. Thanks for the info, and will keep you informed.....8)

Oh and the orings, can I get them from a hardware store, or do I need to go to Suzuki?

Thanks,

[koolaid_kid]

Don't use a silicone sealer. Some use a silicone lubricant (big difference) to try to make the boots more pliable.