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76 DT250 smoking


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hey guys, I have an old DT250 that i just got running smoothly today, runs good, starts on the first/second kick, it has been sitting for 20 years..I put about 4-5 ounces of oil into the gas tank just to make sure its lubing, good news is the auto-lube works. But it smokes like crazy, is this just because of the oil in the gas tank or is it just from sitting 20 years and needs to burn off all the crap? I was thinking the mix is set to high on the auto-lube system? any ideas?

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Hi there,

If it's been sitting for a while I'd be cleaning everything out in the fuel and oil systems and checking the piston/rings/bore as well. No tellling what you've got in there which could be disastrous. You might need to clean out the exhaust. A new plug too.

It will always smoke to some degree and more when the engine is cold. It takes a while for everything to heat up through to the exhaust so should decrease on a longer ride. If you have pre-mixed oil as well as having the autolube on and working, that would obviously make it smokier too. If you're sure the autolube's working ok you can then put straight fuel in but make sure the tank and fuel filter are clean too.. I wouldn't think the atulube being out would contribute much to it being really smokey.

hope that helps,

Gordo

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well i know the auto lube works because i pulled it while it was running for acouple seconds and it stopped being really smokey. changed spark plugs and all that fun stuff, dont really want to mess with the engine to much but i might just end up having to check it, put new oil in it, personally my thoughts would be its running too rich on the oil part.

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watch your gear oil level if that goes down the crank seals are shot, also fuel will get into the gearbox, and if the points side seal is gone air will get into the crankcase causing a weak mixture and seizures in a very short time, also if the fuel leaks out among the points it can cause and explosion blowing expensive covers off the engine, personally after 20 years of standing i would replace the seals as mater of course, imagine if you had stored a pair of rubber bots for 20 years near fuel and oil, they would not be much good i reckon, and i do not think you need to do a full engine tear down to replace the seals on these engines , i maybe wrong though

merv

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