carb problems? 1982 GS550L

[DimitriT]

A search yielded ALOT of carb related material and I've been reading through the posting and getting some ideas but I wanted to present the problem and see if anyone can suggest a course of action.

The bike runs reasonably well but uses alot of gas ~35 mpg.

The previous owner claimed the carbs had been professionally cleaned
but I believe they were never synched or adjusted.

The plugs have heavy carbon on them especially #2 and #3.

The bike idles at 1000-1200 RPM but sometimes falls below this range
and becomes unresponsive. This happens when the bike gets into stop & go traffic, at a light, in a parking lot. A good twist of the throttle seems to fix this temporarily.

I've tried pulling the caps off the plugs while she's idling:
#1 - little change in RPM
#2 - big change in RPM sometimes kills the motor
#3 - change in RPM
#4 - small change in RPM

I've applied the choke after its warmed up with the following results:

10% - no change
30% - RPMs jump to 2300
70% - RPMs steady at 2300
100% - RPMs drop to 1400

There is no black or blue smoke while idling.

I've run the bike out of gas a couple of times (late switch to the reserve)
and noticed that it appears to run on 2 cylinders for a while just before it
completely runs out.

There is some slapping noise coming from #3 or #4. Valve?

I'm taking the bike in to have new tires mounted and they will look at it.
I'm considering having them rebuilding and tuning the carbs - although
I have Clymers on order and may attempt the job myself as a winter project. Depends on how much they want to do the job.

[gspaul]

To be honest I would not trust anyone else to rebuild the carb's but you , these pieces of equipment are quite simple, and of course often stuffed up by"bike mechanics"
Sound's like you maybe flooding on a couple of cylinders,needle valves for the float's, could just be dirt, may need replaceing.
A motor with 4 carb's can never run correctly without a carb sync.
Do it your self my friend, you have found a site with a lot of knowledge, you cant go wrong!

[beby99]

I always have to laugh when people talk about bringing there carbs
to the dealer for sync.....A few years ago I asked the dealer what
they charged for a sync...I almost hit the floor when he quoted $300.

Do it yourself man...the experience is priceless.

[DimitriT]

Found an interesting primer on bike carbs:

http://204.71.0.3/motoprof/moto/mcycle/carb101/carb101.html

[arveejay]

I took my first bank of carbs to shop in town for a clean up and $100.00 later it wasn't any better. Took them apart and found they couldn't have done anything except remove the bowls and spray something in there. Everything was still crudded up. As 0thers have said, Do them yourself, seperate them, remove everything, ask questions, and feel the pride when you hit that start button for the first time after.

[DimitriT]

OK, so I'm gonna try it. I was successful in removing the wheels to get new tires put on (no way I'm paying them an extra $50 to remove and remount the wheels) - so now I'm feeling frisky enough to try something big.

Where do I order the rebuild kit from?

[arveejay]

The rebuild kits are junk, and usually are not needed. The main thing is replacement of all O Rings after the clean up is complete. One of our members sells O Ring kits for next to nothing and all carb parts are re-usable. Do a search for Robert Barr or cycleorings. Very high quality at a rediculous cheap price.

[DimitriT]

Even the float bowl gasket?

I guess I can reuse the gaskets and replace them if there's a leak. Easy enough job.

[arveejay]

The float bowl gaskets are usually reusable. When screws are removed, tap the bowls sideways with a rubber or plastic hammer. This will usually break them loose. If they are stuck to the bottom of the carbs and can't be salvaged they will need replaced. There was a guy selling just the gaskets on ebay for about $2.00 each including shipping, or they should be available at www.bikebandit.com. Some others like www.ronayers.com and Ive heard of some others. Something loke motorcyclecarbs.com Anybody else know for sure?