GS550ES with firing issues PLEASE HELP

[Anonymous]

Hi
I just rebuilt my 83 16v gs550e, it ran fine for about 20 min until it really heated up. once it heated up it stalled and would not start again. Now I got it started again and ran for like a min but had no reving power. So when I turned it off I felt the pipes and noticed 1 and 2 cyl were definatly not firing. I didn't notice any black smoke out the exhaust so I didn't think my piston ring would be bad. Now this bike does have 2, 2barrel carbs so I thought it might be my first carb. What might cause this prob thanks for your help

[Anonymous]

Ok I figued out the 1and 2 firing prob had the wires crossed
The bike runs fine while sitting for about 15min, then when I turn it off and go to turn it back on nothing just spins. Do I have to retourqe my head bolts after rebuild. I see nothing odd comin out the exhaust. What causes no hot start

[Anonymous]

Please someone give me a clue its drivin me nuts
Thanks

[KEITH KRAUSE]

The only changes that happen from starting the bike cold to starting it after 15 minutes is heat.
Heat effects the mixture. If the bike is actually running rich for some reason, the hotter starts will be more difficult for it. Does opening the throttle by 1/3 help the hotter starts? If yes, it's carburetion.
Heat effects the electrical system. Heat building up in poor connections causes resistance to good spark.
Check basic maintenance things first. Carbs clean? Floats adjusted? Mixture screws set correctly? Carbs vacuum synched? Intake leak checks? Air filter clean? Do you have a good blue spark at all plugs? Solid/clean connections? Correct plugs, correctly gapped?

[Anonymous]

Thanks for getting back to me
No it doesn't help to have the throttle open at all it just doesn't kick at all when its hot it will run but if I turn it off its over. The carbs ran on the motor before the rebuild so I don't think it would be a big difference. One Question I have I took the little plugs out that go before the intake valves and after the butterflys (basically the manifold). And just turned the motor over as the motor spun I felt air being forced out these holes. Why would there be a Positive air pressure in the manifold as I'm tiring to start the bike????

[KEITH KRAUSE]

I'm not sure what to think about the vacuum question. All I can think of is the intake valves not sealing. I've never tried turning the motor over with those screws removed. Might be normal to feel some air escape.
As for you thinking the carbs must be fine, how long did they sit while you did the rebuild? Doesn't take long for the gas to varnish up the passages, etc. When were the carbs serviced? Take nothing for granted. I'd still check all the basics I described.

[Anonymous]

One more thing if I rev it up and then just let go of the thottle it takes a long time for the revs to come down. could this be extra air getin in

[KEITH KRAUSE]

One more thing if I rev it up and then just let go of the thottle it takes a long time for the revs to come down. could this be extra air getin in

If you're sure the throttle cable and throttle plates are moving smoothly, then a lean condition would cause the slow to return rpm's. Most likely cause for intake leaks are the manifolds or the o-rings inside them, if yours has o-rings. Sometimes you're lucky and it's loose manifold clamps.

[AOD]

Hmmn, what about bad coils? They tend to fail when they get hot.

Run it up to where it dies, pull off a spark plug boot and put a new plug in. Ground the plug to the block, crank the engine, watch for spark. Repeat on all plug wires.

If you have spark, then you have a fuel problem.

~Adam

[Anonymous]

I think I have narrowed it down
I pushed the carbs into the manafold boots really well and tried it again. now it starts while hot but not unless I give it little to no thottle. And even when it is hot it idles better with some choke on. Which makes me think it has a vacum leak. Also I almost closed the air box and noticed no difference in idle speed.
Thanks

[KEITH KRAUSE]

I think I have narrowed it down
I pushed the carbs into the manafold boots really well and tried it again. now it starts while hot but not unless I give it little to no thottle. And even when it is hot it idles better with some choke on. Which makes me think it has a vacum leak. Also I almost closed the air box and noticed no difference in idle speed.
Thanks

Hot starts but only with minimal or closed throttle shows a lean condition. So does your choke and airbox test.
Check the manifolds for any cracking or hardness, also any o-rings and stretched clamps.
If no problems found, then a carb clean, float level check, check mixture screw adjustments and vacuum synch is needed.

[Anonymous]

is there any cheap place to get the o rings for this bike. Do I have to buy thought the dealer can I get them at a hardware store

[KEITH KRAUSE]

is there any cheap place to get the o rings for this bike. Do I have to buy thought the dealer can I get them at a hardware store

Make sure your manifolds have o-rings first. Some models don't.
Look in your manual or check out Bike Bandit.
I've always bought them from the local Suzuki dealer because it's convenient and they're cheap. At least you know what you're getting from the dealer. The o-rings are made of a certain kind of heat resistant rubber. I wouldn't go to the hardware store to buy them.

[Anonymous]

Thanks for all the help so far heres what I did
I bought new o rings the old ones were hard and flatted out I also got new clamps for the manifold boots. I checked my manifold and it looks fine not one crack. But now when it is hot it idles and starts better with alittle choke like before but not as bad. It revs fine above 3k it is quick but below 3k it boggs under just reving it up. It still seems to be lean I think. I did have the carbs apart and I didn't sync them would this be a place to start.

[KEITH KRAUSE]

Yes, a good carb synch may fix you up. This should be done as normal maintenance.
As I said earlier, the mixture screws may have been moved? If so, try turning them in or out at 1/2 turn increments (out=richer, in=leaner) and test. Keep a record of the adjustments so you can return the screws if you don't like the results.
Also, the carbs may be dirty or varnished up after sitting during the rebuild.