xj550 Will not run without the choke

Hey all,

I just got a 550, and it runs fine with the choke on full or half, but without choke it instantly stalls out.

I can only assume this isn't a simple fix (like adjusting the ide screws?).

The carbs were all taken apart and cleaned, and I trust my buddy (who is an auto mechanic) that he is telling me the truth, but I am not sure if they are synced properly. How would I know?

Any other ideas?

I am currently riding around just fine with the choke on all th etime, but it does make some high rpms because of it.

Thanks!

 

Check your carb boots for cracks. If they are letting air in then your bike would act exactly like you say it is.

 

Um, I would check to make sure they are balanced properly (search these forums about that, and building a tool to balance them correctly). Also, if your buddy just cleaned your carbs then you might wanna go one and tune the engine as well (pilot screws). Just my two bits.

 

Thanks; what type of sealer do you guys recommend if the boots are all cracked?

 

Atuo Goop works perfectly fine. If they are to bad you will have to order new ones.

 

I meant auto.

 

It seems the first two cylinders are not firing or not firing well. (the boots seem fine).

When running, I can hold my hand on the exhaust of the two left side headers but the right sides seem to be firing well and of course hot ot the touch. I tried replacing the spark plugs, but got the same results.

Fun!

 

Pull the carbs back off and clean them better. It will then run. There are lots and lots of tiny little holes that an auto mechanic wouldn't necessarily know to clean. Mine was doing the same thing as yours.

 

I also have a XJ550 (1981) and have similar problems with my bike needing the choke.

The advice I was given was to clean the carbs, but it seems like you've already done that. The next step would be to adjust your pilot screw to get the right air-fuel mixture into the cylinders. Turning the screw in to increase the idle speed, and out to decrease the idle speed. The step after that would be to tune the carburetors.

But before doing that, it sounds like you are having some more serious problems with the first two cylinders not firing. First thing I'd do is to pull the plugs and see if they've got any crud on them. If they do, this is an indication of any type of problem with the firing of the cylinders (ie, too rich of a mixture, oil in the fuel, etc). The clymer manual has a good chart on fouled spark plugs and what the typical causes are.

If the spark plugs look ok, check the gap with a feeler gauge to make sure they are within spec. If that's ok, test those bad boys for a spark. For liability issues, I don't want to offer any advice on this procedure, but again the clymer manual has good instructions and you can probably just ask you friend as well.

Good luck!

 

If you only have two cylinders that would be your problem. The choke would have to be on in order to dump as much fuel into the two hot cylinders in order to keep the engine running. Fix that problem and you bike will probablly run fine. Also try switching to iridium plugs. They are ten time better than the cheap ones, but wait till you get your cylinders firing because you will probablly burn a few out figuring out your problem.