I got a 95 GS over a month ago now, and it ran decent enough to ride around town. Having some running issues, I pulled, and cleaned the carbs and it hasn't run right since. Well, not consistently anyway. I adjusted the pilots out to 2.5, the bike huffed white smoke pretty bad, but ran like a raped ape. Rode about 20 mi. with no issues around town, and let it sit for 5 hours. When I went to start it once again to ride to a friends house, it had no power. Struggled to rev at all and would NOT got past 10k. I go out and fiddle around with it today, and it's still running like crap. I move the pilot screws around a bit, and get nowhere. After resetting the pilots to 2.5 turns, and starting it runs great and huffs smoke again. smoking eventually goes away, and bike continues to run good. Anybody have any ideas what can be causing this?
Mine's a '95 too. I never push it past about 7 K rpm - no benefit any higher that I can see.
You did the carb clean routine - might consider worn valve guides for the smoke ? Maybe valve clearances need check ?
Could be ignition problem(s) - unreliable connection, coil, coil wire, spark plug etc - even the ignition control box can be suspect on a bike that old. Safety switches making only intermittent contact ?
A marginal battery can cause the bike to run like crap. Bad ground(s) possibly ?
I usually keep it lower, but for Diag, I thought it would be helpful.
It did it again. I put about 50 mi. on it Fri. night, went to take it out
tonight, and hesitates/sluggish rev, and won't rev past 10K Gonna
go take your advice, and see but in the meantime, any other ideas?
Well, if it's white smoke, it's more than likely oil burning. I think worn valve guides would only blow the smoke on startup and a bit after. Do you get the smoke at all during the ride? It could also be condensation. Check to see if it's actually smoke or water burnoff. Check to see if there's oil in the air filter/housing. Did you change the oil recently? I'd do as suggested with the valve check and check.
It's a long shot, and lets hope you didn't do this, but when you messed with the carbs, it may have been possible that you created an air leak, clogged the jets, or set the mixture screws too lean, messed up the diaphragm, etc. and ran it for an extended period. Running too lean for extended periods of time can do nasty things. Again, it's a long shot, but I'd check your compression to be sure. Just borrow a compression gauge from autozone. It takes like 10 minutes.
Take your plugs out and read them. Let us know what they tell you.
The white smoke is really throwing me off. It sounds like a carb issue, but it's acting like a piston ring/valve issue. Somebody correct me if I'm wrong, but if the piston ring(s) were fried, starting it cold would produce no smoke, but once the engine gets going, the smoke would start. Valve guides would cause white smoke at the start and go away.
So, if you've ran lean, burned up your guides, you would have oil in the cylinder which gets burned at start-up. It would run OK during cold temps, but as soon as it heated up, the guides would being to malfunction worse causing poor performance. It may take a while for the guides to contract, causing re-start issues, contract finally and better seat the valves which would allow start-up and again a puff of white smoke at start-up.
Just a guess, but, yeah, sounds like a lean running valve/guide issue. Who knows, though. It could be something stupid I'm looking past. GL.
The left plug was black, and getting no spark. That's gas foul no? I cleaned it, and got it sparking again and swapped the plugs from side to side. If it happens again on the same cylinder, I'll try swapping coils side to side. If it STILL happens on the same cyl. I am going to think the CDI is gone. Does that sound about right? I think the oil burning is just a coincidence. With 35,000 mi. I'm assuming more than just basic maintenence is in order very soon, but I wanna see if I can get it running well enough to ride for a bit first.
UPDATE: After swapping the coils, it's clear that the problem is specific to the cylinder. So now Im thinking the CDI or a fuel delivery issue. I went to sink the carbs, and got no vacuum on the right carb to use to sync. Is that a common issue, and would it cause the bike to dump excess fuel in theh opposite cylinder? How common is it for the CDI to let go?