My father recently acquired a 1997 Suzuki dr200se. It had been sitting for a number of years and only has 500 miles on it. He rebuilt the carburetor to get it running and we immediately noticed that it was burning a lot of oil. Smoke was pouring out of the exhaust. He tore down the top end of the engine to find that someone had installed an oversize piston and rings. But what was interesting, was that one of the rings had too big of a gap. He installed brand new piston rings and made sure all the end gaps were within spec. He also installed new valve seals for good measure. After re-assembly, there is no change. It still smokes. We are wondering where to go from here. Possibly a cracked head or cylinder jug?? Any suggestions would be appreicated. Thanks.
Interesting...I wouldn't expect a cracked head or cylinder to smoke badly. It's air cooled, right? So the smoke is definitely burning oil? Is there any sort of compression bypass valve for starting?
Mezzanine said:
Interesting...I wouldn't expect a cracked head or cylinder to smoke badly. It's air cooled, right? So the smoke is definitely burning oil? Is there any sort of compression bypass valve for starting?
Yeah, its air cooled with no decompression valve. When its running, it produces a constant cloud of black smoke. And after you turn it off, oil drips onto the ground from the exhaust.
Well that's a clue! I'd pull the exhaust off and closely inspect the port to see if there's a crack or some wear into an oil gallery. What does the cylinder and spark plug look like? Is the oil getting into the cylinder and burning there, or is it getting in the exhaust itself?
Well, good news! It seems as if all of the smoke and burning oil was created by leftover oil in the exhaust system from before I replaced the rings. After cleaning the carb again and fixing the stuck slide, it runs great!
What a relief! This was shaping up to be a real mystery, otherwise. Glad to hear it.
