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DR350 smoking bad oil vent into carb

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My bike is smoking real bad because the crankcase vent is pushing oil into the carb boot, all levels are good. I can drain the lower sump, the bike runs fine for about 5 mins until the sump fills again. I have seen this happen on 350's in other threads but have not seen the fix, Any suggestions.

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Can you explain to us exactly how you check your oil level?

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i drain the bike, bottom sump, and frame sump, no oil left in bike. I add a quart and a half and it indicates I still need more oil. I don't believe the oil level is in question. It seems the bike runs perfect until the sump fills up and starts to come up the vent and into the carb stream and smokes real bad. Searching the web, other people have had this problem and I have not seen a remedy. Even after it smokes real bad the oil level is at the add mark on the stick. When I say smoke, imean alot of smoke. the oil is pushing up the vent and goes right through to the exhaust. I am a mechanic and I am confused on this.

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Have you ever checked the metal screen that filters the oil in the frame? Maybe if that's clogged it's causing the oil to back log and fill the case....only thing I can think of.

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I was asking you about your exact procedure for checking your oil level between oil changes.

Also, If it's an S model, do you still have the stock vacuum petcock installed on the bike?

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Yes, I cleaned the screen in the frame, the vent on the gas tank is no longer hooked to the cock. Could it be a oil timing issue? This is a low hour bike and I can't imagine a bad pump. Exactly when do you check the small bolt on the side of the oil cover? It seem the engine is pumping more to the beariings than what is going back to the resivour. What actually regulates the oil level in the top sump.

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I would drain both drain nuts. Add a quart run the bike for a second to get the oil to the sump until it runs out the weep hole. Then I would pour the rest of the oil 3/4 quart into the top tank. My bike says 1700ml. Hope this is somewhat right.

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