2/82 gs1100 engine popping and sputtering above 4k rpms

[Anonymous]

Hi, im new to the board, and was recently gifted a 2/82 (as per the frame) gs1100, it had been used as a drag bike by my uncle, its a basicly stock bike except the headers (dont ask i have no idea) i believe. my problem is that the bike came with no air box or pod air filters, and above 4k rpms it sputters, from what i hear a air flow/carb jetting mismatch should cause the bike to be almost unrideable at higher rpms, the bike is very rideable but it is loud obnoxious and, underpreforming (i suspect) any suggestions would be much appriciated.


Oh and a 2/82 on the frame makes it a 1982 not an 83... right?

[Anonymous]

From what I have learned here, the carbs and vacuum leaks can lead to difficult running and are common leads on the GS. First thing to do is yank er carbs off and pull the bowls off and clean out all the passages with spray. Pop the tops and make sure all the rubber is not torn and pliable, carefully. Check the slides for scuffing on the sides, clean all that out too. Then I would suggest having the carbs synch'd. From there I think it would move on towards the ignition and electrical.

[Hap Call]

1. If the stock air box is available, replace it. Replace the packing in the muffler. See if those two things help clear up the problem.

1a. If the stock air box is not available, put on pods and rejet the carbs. You are running lean by allowing too much air in but not enough fuel. This could damage the engine in the long run. Don't forget to repack the muffler. You can get the repack material from Dennis Kirk, an aftermarket parts dealer.

2. Adjust the valve, replace the plugs, and synch the carbs.

If neither of these two options work, check back in here and give us some more symptoms.

Hap

[Jethro]

Oh and a 2/82 on the frame makes it a 1982 not an 83... right?

Most likely, but not nessecarily. What color is your motor? Do you have an 85 speedo? If your motor is unpainted aluminum instead of black, and you have an 85mph speedo, you most likely have an 82. As long as we are talking about the E models, they were the most popular drag models.

[Anonymous]

A stock drag bike? Hmmmm In any case, before mucking around with the carburetors, don't make assumptions with the rest of the bike's condition/tune. I would get a Clymer manual and tune the bike up. The symptoms you describe are not unique to the carburetors as far as tune goes. Adjust valves and cam chain and then get into the igntion. Your symptoms sound like a sticky mechanical ignition advance. Make sure yours is clean and lubricated before tackling the carbs. Set the ignition timing and then pull the carbs off and check the jetting before determining what needs to be done with carb jetting. As far as air boxes go, the stock airbox provides quiet air to the carbs with little turbulance and while the OEM airbox may not provide as much air to the carbs, the bike will operate more smoothly with it in place. If you choose pods, get some that can be cleaned/oiled if you intend on keeping the bike for any period of time. If you buy less expensive paper element pods, these are essentially disposable filters. JC Whitney sells pod UNI filters that are less expensive than K&N filters and perform about as well. These can be cleaned and oiled and will last indefinitely. If you do install pods, and have aftermarket pipes, go up 3 sizes (jets come in 2.5 increments) for the main jets and 1 size for the pilots as a good starting point. The bike will run fine and you can fine tune at your liesure.

[Anonymous]

yeah it wasnt so much a drag bike, as a potential drag bike, it was bought in perfect running order (and dont look bad to boot) at an auction for 350 dollars, the guy thought it didnt run, because he had the spark plugs wired wrong, my uncle bought it thinking he would drag it, did so 2 times i believe and decided that the bike wasnt comfortable enought (hes a harley softail man) and parked it.

and yeah its got an 85mph speedo, and the engine is unpainted aluminium so i assume its an 82, i also wish to know where i can find the 2 bits of uhhh... faring that cover the wireing and battery area, between the tank and the tail.

[Hap Call]

... i also wish to know where i can find the 2 bits of uhhh... faring that cover the wireing and battery area, between the tank and the tail.

They can be found on eBay. I believe that there is a complete body set for you bike on there at this time. Just do a search under "GS1100".

Hap