GS550L Won't run after carb work

[scott808]

Thanks. I tested the petcock, lines and fuel filter. I get plenty of gas in the bowl, but I can't figure out why it is not starting. It is not electircal because after sitting for a while it will start and run with full choke for a minute, but if I touch the throttle it will quit. I replaced the float valves just in case, but no change. The tank is full so I have pressure. I have the idle mix screws at 3 and a half, and I have tried several different settings.

[chuck hahn]

3 1/2...HOLY CHIT!!!! Theres a problem right there..WAY WAY too rich. Set them back to lightly seated and go out 2 turns. I would also pull them right out and see if theres any bent or chipped tips on the screws. If so, get the pilot holes in the back of the throat cleared of any tip pieces that may be stuck in them.

Also, you gotta let these 4 cyclinder bikes warm up before trying to apply the throttle..good minute at least. I start my bikes and ease off the choke till its around 1500 to 2000 RPMs and let it sit for a minute. If the cylinders are cold it will simply stall right away if you try to give it some gas.

The cylinders NEED the heat to help vaporize the intake mixture so it burns better. Try these and report back as to how she does then.


EDIT...Pull and clean the plugs as good as you can too..bet they are pretty sooty.

[OldVet66]

 If so, get the pilot holes in the back of the throat cleared of any tip pieces that may be stuck in them.

Chuck wouldn't an '83 have CV Carburetors?

[chuck hahn]

Yes your right...I was referring to the hole the mixture screws fit in to at then top..down inside the hole. My "termionology" for it was probably wrong.


I meant to check the bottom of the holes of the screws show signs of chipping or anything broke off them. Should be able to see any little specks of brass down them with a good flashlight.

I have only had 1 CXV carbed bike and that was quite a while ago..My brain is stuck on the VMs because all my current Suzukis have them.

[chuck hahn]

Maybe test the slides by blowing some air into the oval port at the tops. See if the sldies all move and if they are moving in sync with each other.

I persoanllay think CV carbs were the worst thing to do to any bike.

[OldVet66]

My brain is stuck on the VMs because all my current Suzukis have them.

Not a bad place to be they are very nice carburetors.

[chuck hahn]

VMs are for sure way easier to work on and tune than CVs are. The one bike i had with the was the 82 1100 that Stahlgrau333 up in Norman Oklahoma has now.

[JEEPRUSTY]

3.5 is 1 - 1.5 too many turns. Ill bet you plugs are now fouled compounding the problem.
As I said this bike hates running out of gas it is super hard to start even on prime when it does so.

[scott808]

Thanks guys. I will check. But with this type of carb how many turns out should the mix screws be set at?

[JEEPRUSTY]

mine are set at 2.5 I think.
I could go check but its raining.

[scott808]

Uodate: This is driving me crazy.

The bike starts and runs on starting fuild. Sounds awesome.

If I pull the gas line off the carb I get a steady flow of gas.

When I pulled the carbs I carefully removed the bowls without tiping and both were plenty full.

I checked all the passageways I could see and blew carb cleaner and compressed air through. I soaked and visually checked each jet before I reassembled the carb.

The plugs are not wet after cranking the started repeatedly. They look good.

The bike ran OK before I touched the carbs. But it would quit for no apparent reason and not restart until it sat for a while.

What could be stopping the flow of gas from the bowl to the cylinders?

Somebody please tell me what I am missing?

[tom203]

Uodate: This is driving me crazy.



The plugs are not wet after cranking the started repeatedly.

What could be stopping the flow of gas from the bowl to the cylinders?

Somebody please tell me what I am missing?

I enjoy being redundant !.... that stuff about plugs not wet after cranking

"Anyways, pulling jets and cleaning them is nice, but this doesn't ensure clean passages from pilot jets up thru and into carb throats- if they are gunked up, not enough fuel and engine will fall flat. "

[scott808]

Normally I would agree with you, but the bike was funning fairly well before I started and although I did not perform a complete carb overhaul to GSForum standards. I did check very little passageway. The bike should a least start or chug a little. Without the starting fluid I can't get anything unless the choke is on full. There must be something else.

[elrico]

Large O rings between the intake stubs and cylinder head are probably shrunk and allowing massive amounts air to be drawn in first when cranking engine during start up attempts.Engine cylinders are filling mostly with air:very little gas in the mixture.Air/gas mixture ratio is mostly air,will not ignite in cylinders(too little fuel=dry spark plugs).Pull carbs and remove intake stubs and install new proper size O rings.

[hjfisk]

What have you got for voltage at the coils, a weak spark there may not fire gasoline but would starting fluid.