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Discussion Starter · #1 ·
Hi I just bought my first bike last week, a 1982 Suzuki GS300L which didn't run but turned over. I cleaned the whole fuel system and rebuilt the carbs and got it to run (also the airbox has been replaced with K&N air filters.) There is significantly more exhaust coming from the right side of the bike. The left side exhaust has a normal amount of exhaust, the right side ejects a lot of smoke even at low idle, and continues to eject this smoke up to a minute after the bike has been turned off. What is most likely the problem? Thanks for any input!
 

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You didn't say how many miles are on it.
But my first thought would be stuck rings after sitting for so long.
I'd say take it out and run it and maybe they'll loosen up.
But keep a close eye on your oil supply.
 

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What color is the smoke.

Can you do a compression test?

You could also pull the plugs and check their appearance.
 

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If it really has only 5,000 miles, internally that engine should be like brand new, except for maybe the oil seals. And that may be why it's smoking.
Again, keep a good eye on your oil supply.
But I'd take it out and run it and see if the problem clears up
or gets worse.
 

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Discussion Starter · #6 ·
Smoke is a thick white/light gray color. Can't do a compression test but I've check the plugs and they're both a bit wet but look the same. When I got the bike the right plug was significantly more gunked up than the left. Will take it out tomorrow to see if it clears up and check the oil before/after.
 

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Hi, I have a 1973 Honda Cb500//four. When I bought it it ran only on choke. I Cleaned the carbs, replaced sparkplugs, and sparkplug caps. I got it to run yesterday and it ran well with the choke off. I turned it on this morning and it ran well, then it turned off on its own. By then i had to leave to work. When i got home i turned it on again and turned it on. It ran for 30 seconds and turned off. After that it will start but only if give it throttle, but it will turn off after i let the throttle go, even if i hold it at 4k revs for like a minute. also it will only turn on with the choke off. Any advice will help, thank you!
 

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Alex: What condition is the tank in? Is there a lot of crud in it? How old is the petcock? It sounds like contamination washed into your newly cleaned carbs and has gunked stuff up again.

Have you checked the valve clearance and ignition timing? Just curious.
 

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Thank you for your reply! I cleaned the tank when i first got it, i might clean it again now that you bring it up. What is a petcock? I fairly new, this is my first bike.
So your saying that I have to clean the carbs again? I think i know what the valve clearence is, they look clean, and i dont know what the ignition timing is as well....
 

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The petcock is the fuel valve that the fuel line hooks into at the tank. There are rubber parts in there that can degrade after a few decades and become rubber grit in the fuel system.

Is there any sort of rust color in the fuel tank?

Yes, it sounds like the carbs got gunked up again by some debris.

Valve clearance, ignition timing, and compression test are 3 things I like to have done/set before working on carbs. I'm not so much worried about the compression test right now as you said it would run for a bit. Valve clearance and ignition adjustment should be done.

Read about them here: (it's easier than me explaining them.)

Motorcycle Repair Course

Also, a repair manual will be worth its weight in gold given how old your bike is.
 
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Just checking your OP. I will assume it has two cylinders and two carbs. If it is white smoke it is too rich, as in too much fuel. If it is blue smoke it is oil. Because it puffs after shutoff, and the colour you describe, I think it is too rich. But before we blame the carb on that side, too rich can also be fuel in the correct amount that is not being burned. That could be from an ignition problem, or low compression. So you need to check the compression which is pretty easy, and check the spark, again pretty easy. Good compression and good spark will lead you to the carburetor, but one last thing. Check that the exhaust pipes have good flow.

UK
 

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Thank you so much. Its my senior project for high school and i was stressed. I'm learning on my own reading manuals and articles. This is a lot of help!

I just check the tank and it still has some rust parts that i missed. Hopefully it will run better after i clean the tank so i dont have to clean the carbs again.
 

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Thank you so much. Its my senior project for high school and i was stressed. I'm learning on my own reading manuals and articles. This is a lot of help!

I just check the tank and it still has some rust parts that i missed. Hopefully it will run better after i clean the tank so i dont have to clean the carbs again.
You'll need to clean the carbs again after you clean the tank again since you said it stops running. Something is plugging one or some of the tiny passages. And take UK's advice about an inline filter from tank to carbs. You might not have had to clean the carbs again had there been one there.
 
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