Advice B/4 I tear it down

[mrquadriga]

Newbie here and perhaps this has been discussed before...when my 1980 GS 1100L with 19K on it starts up, fine no problems, after it's warm, it idles at about 2500-3000 rpm's. I've ran a half a dozen tanks of seafoam or stabil thru it, nothing seems to help. Also, running premium in the tank seems to make it idle higher than regular gas. Air Leak or jets? I'm waiting for my manuals to arrive, (I bought both Haynes and Clymer) and have about six months to do everything that needs to be done. (dog-gone upper northern hemisphere winters!) Where would you people focus on first? I'd like to try something before it gets too cold to take a test drive, (i.e. *ss deep snow!) so here's your chance to weigh in. Just reading some of the thousands of posts on this site have given me the confidence to at least try to solve this problem myself---the regular contributors here have tons of knowledge and are willing to help. Thanks so much for this site and I'm looking forward to your replies. - Pete

[earlfor]

What color is the center ceramic on each of the spark plugs. My inclination is that the idle mixtures could be off a little bit, and the the carbs are not well synchronized. Possibly a small leak in the induction system too.

Earl

[Anonymous]

Had the same problem on one of my 550's. Turned out to be an airleak where the carbs boots meet the cylinder head. Replaced the "O" rings under those babies, resynch'd the carbs and all was well. They get brittle and break. Make sure you use OEM rings, they are made for the higher temps.

You can check for a air leak by spraying wd-40 or something similiar (non flammable please!!) around the intake boots on your carbs and see if the rpms change.. do a search on the fourms for how to do this properly. It may also be listed in your manual - it was in one of mine. I am just telling you my experience. MANY, MANY more knowledgeable and experienced people on these forums than I, and are willing to help with the proper info!!

[earlfor]

Just a note. For spraying to locate induction leaks, I use an old windex bottle filled with WATER. Its commonly available, user friendly and not too expensive. LOL

Earl

[KEITH KRAUSE]

Sounds like an intake leak at the manifolds. Before anything else, make sure the clamps are tight first. If that's not it, check the manifolds for cracking, but it's most likely the o-rings. Check with a water mist bottle. The rpm's will drop for a moment if you hit the leak. Be aware the water test doesn't always expose the leak because it's hard to get the spray into every spot. Get genuine Suzuki o-rings as suggested and apply some hi-temp' bearing grease to them to help them last. I would replace the stock Phillips manifold screws with Allens. Torque them to 6 ft/lb.
If this is the scenario: start bike cold, idles OK, rpm's rise up as it gets hotter, turn down idle and all seems OK, park bike until it's cold again, now the bike won't start until you turn up the idle adjuster..then it's an intake leak.

[mrquadriga]

WOW thanks! I have already done the WD-40 thing, nothing changed. Looks like I'm going to try the o-ring thing next after I check the clamps. The high today was 33 degrees fairenheit with a 25 mph wind. not condusive to riding and warming it up. Thanks for the tip and Earl i'll check the plugs too. Stay tuned.

[KEITH KRAUSE]

Just a thought, you never know.
There's a small bolt with a crush washer (copper?) on each manifold or carb. If the washers are not on or the bolts are loose you'll get intake leaks. These bolts are removed to connect a vacuum synch tool adapter. Not sure where yours are located.
Just an easy thing to check. They usually don't loosen by themselves, but I don't know the bikes history so I thought I'd mention it.

[mrquadriga]

Okay, here we go, removed the spark plugs and the color of the ceramic was white (good burn?) on three of them, one was wet. I know you're gonna ask me which one, I don't have my manuals yet, (darn shipper!)so it is the one if you're sitting on the bike, is closest to your right knee. going to the store today to get new ones anyway so what should be the gap in case I need to gap them? Thanks again for all your help, just a warning, you're dealing with a guy that has hardly turned a wrench in his life but because of your help has already removed most of the chrome on the bike for a good cleaning and has done my first oil change ever. Pete

[KEITH KRAUSE]

The three white plugs are burning lean. My previous advice applies.
Your #4 plug is the wet one. Was it wet from gas or oil? Gas would smell strong and it would evaporate soon if the plug just sits out. Oil would be stickier and not evaporate.
What color was this plug? Does your bike burn oil (whitish/blue smoke) at all? Do you ever notice any gas under the bike?