1985 Suzuki GS550 -- Won't start + mandatory details

[Anonymous]

Well, now I've gone and put my foot into it.

I took a motorcycle repair course at the local tech college. I decided to put my newly learned skills to the test and purchased a bike that I could afford to destroy. So far, I've put about 12 hours into it and need help.

I've checked the FAQ for this area and have found similar stories. Unfortunately, I've tried the obvious cures proposed.

The Story

I was told the bike was basically sound and did, in fact, run well as of October of 2004. I haven't been able to get the bike to start.

Relevant facts:
1985 Suzuki GS550ES with ~25K miles that last ran in October of 2004.

I turn the key and get power to the gauges, headlight and accessory system as I would expect. When I push the start button, the starter motor engages and spins the engine as you would expect. I try this a few times and I can't get the engine to start.

I have entirely removed the carburetors, taken them apart, cleaned them, put them back together and re-installed them on the manifold. When I sprayed carb-cleaner into the jets, it came out the other end just fine so I don't think there's any obstructions. I didn't really find any gunk or green gas anywhere in the assembly. I know for a fact that gasoline makes its way from the tank into the float bowl of the carb in that I unscrewed the drain plug from the float bowls, attached the tank, switched the fuel petcock on and in a second or two saw gas draining from the bowl. So, the fuel system appears to be okay.

I thought that the ignition system might be faulty. I proceded to remove each spark plug from its cylinder, reconnect its lead and press the start button. Each spark plug produces a blue spark.

I don't get it. The carbs get fuel. The jets appear to be clear. The plugs generate a spark. I put my hand close to the intake of the carb and can feel air being drawn into it so I know the engine is inhaling air.

I even tried spraying some starting fluid into the intake of each barrel of the carb. The engine still won't start. Now, to top it off, I've managed to wear the battery down.

Why won't the engine start?

What am I doing wrong?

[silverhorse47]

No compression?

S.

[SqDancerLynn1]

I would replace the spark plugs Recharge the battery. It sounds like you have not replaced the air cleaner yet ??? NONE of the GS bikes will run/start properly with out the air box installed. Hook up some jumper cables to your car battery if you have one available, DO NOT have the car running & try it again Make sure to give it full choke, NO throtle, turn fuel valver to prime for few seconds, turn back to run position and hit the starter button hopefully it will run
Make sure to have fresh gas

[Anonymous]

1985 Suzuki GS550 -- Won't start + mandatory details

I certainly agree when I rebuilt my engine it was a hell of a time to get it running.

Scared me real bad.

Solution- Adjust the choke cable properly (install the airbox) let it prime with fuel for a few minutes, and literally blocked the whole airbox inlet with my arm.

Bada Bing, and when It does start Sync the Carbs

[KennyJ]

Ah...my bike! Good choice in mounts, but not the easiest to work on. The 2 barrel carbs are...interesting. I would say without the airbox on it is going to be really tought to start. Mine has never been an easy starting machine, though it runs well, its terribly cold blooded.

I always replace the pilot jets when I take it apart, period! They are so small are impossible to clean well, it is just easier! Also, you have to make sure that hole in the bottom of the carb bowl is clean, as well as the tube up the side of the bowl (as this feeds the enricher circuit). If you didn't remove the mixture screws (the capped ones), I would also clean those out. They are really small passages that plug easily. I used compressed air to remove the plugs (push the blow tip against the hole in the plug and it pushes them right out).

If you have spark, well, you have spark. Many times, in cold weather, i jump it off a car battery. The original battery doesn't seem to have much punch when cold. Only let the starter turn for a short period of time, it can burn up easy with too much cranking and no cooling.

I also use starting fluid (NAPA premium, higher ether content) for the first start of the season to keep the battery from dying. I tend to keep shooting it into the airbox until it "catches" and runs on both carbs. Are you sure the carbs are filling totally? Even on prime, mine struggles to start.

You could also have a massive vacuum leak, but that might be harder to find!

Good luck!
Kenny
(going on 20 years of ownership of my 85 550E)

[Anonymous]

Those weird "2 barrel" carbs like I have on my GS550LF.

Mine had major problem with pilot jets. Took me 2 cleaning attempts to get it right. Darn things clog so easily. And, get this, I had been riding the thing pretty much every day since I got it in June 2004. It was starting to show signs of clogging early-on because I had had a difficult time getting up to 25 MHP for the riding test at the BMV! It kept getting worse, not better no matter what additive I put in the gas.

Tear those carbs down again. Be sure to pull all the jets (there are TWO sets, mains are obvious, look around and you'll see the PILOT jets) and clean each one with Chemtool B12 (the gas additive chemical not the tank soaking stuff) - same company makes the gas additive. Spray can carb cleaner is crap. Get the Chemtool B12. It works. An Army mechanic put me onto the B12.

My idle mixture screws were way off too. Be sure to pull the plugs in front, topside of the carbs by drilling a hole in the middle of the little plugs and using a tiny screw (or like I did a picture frame hanging hook) screwed into the freshly drilled hole. Use lots of PB Blaster or other penetrating oil if the setting screws won't come out. Turn them Clockwise (in) and count the turns as you go. That'll at least give you an idea where to put them when you get the carbs back together again.

Weird carbs but kind of neat in design, 2 barrels but using one float, etc. If you look inside the boots that go to the engine though, you'll see they actually are SEPARATE feeding into the engine. I thought that was weird. Definitely different from a car carb.

Good luck. Follow everyone's advice. I'm not repeating others good advice, just what I know worked for me.

P.S. The spark plugs should be REALLY wet with gas if the fuel system is working !!! If you're getting a good blue spark on all plugs then probably OK. Still, I've had valve timing problems on a car prove me wrong. If all everything else works, timing was last to check and that was it on the car. Not likely on a bike with a timing chain! (Still an interesting tidbit)




Tim