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deputy dawg

smokey mar

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I'd give it a chance to clean out any build up of old 2stroke in engine / exhaust before looking for a problem. Then wet side crank seal. Burning engine / gear oil looks and smells differently from 2stroke.

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Agree with what B40 said.  For comparison, my MAR, I had switched oils and all is good.  However at a recent event, between the hill sections and immediate connector sections, my pipe was smoking pretty good.  Laughing about it, we questioned if the bike was going to burn to the ground, which it did not.  Merely residue built up from slower running.

But do not rule out the oil seal, or retightening the case screws, though that should not be a concern with a fresh rebuild.

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My own MAR starting smoking suddenly one day, but had been fine when ridden the previous week.

turned out to be crank oil seal on clutch side had somehow got stuck to the crankshaft and was rotating with it   !

{ no idea how this could happen, but it did }

fitted new seal with some adhesive and its been fine since, worst part of the job was removing the cush-drive off the Crankshaft to access the seal

 

 

 

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well I've just been out on it and when its up to running temp it smokes excessively, with the engine stopped it smoke for quite a while afterwards, I've taken the plug out and its a nice biscuit colour would a crank seal not foul the plug if it was gone

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7 hours ago, deputy dawg said:

well I've just been out on it and when its up to running temp it smokes excessively, with the engine stopped it smoke for quite a while afterwards, I've taken the plug out and its a nice biscuit colour would a crank seal not foul the plug if it was gone

If you've still got smoke coming out the exhaust after you stop the motor, it means that combustion is happening inside the exhaust pipe which means that there is gunk in there. If you want to be smoke-free sooner rather than later, then take the pipe off and clean it out.

A transmission oil leak into the engine produces foul-smelling white exhaust smoke and if that was your problem the spark plug tip would look oily and your primary drive case would be losing oil fast.

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6 minutes ago, feetupfun said:

If you've still got smoke coming out the exhaust after you stop the motor, it means that combustion is happening inside the exhaust pipe which means that there is gunk in there. If you want to be smoke-free sooner rather than later, then take the pipe off and clean it out.

A transmission oil leak into the engine produces foul-smelling white exhaust smoke and if that was your problem the spark plug tip would look oily and your primary drive case would be losing oil fast.

Agree.  As I posted, after switching oils and getting tne pipe pretty hot, just sitting there not running smoke was coming out the pipe.  Plug was fun.  After it did its thing, smoke subsided.

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thank you for the replies much appreciated, well i bit the bullet and took the pipe off and cut it open to clean it out, the packing was smouldering quite a bit by the time i had finished so i was glad i decided to do it. i cleaned it all out and repacked it and welded it back up, and so will have to wait until next weekend for a test run.Im very glad i didn't burn it out 

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10 hours ago, deputy dawg said:

thank you for the replies much appreciated, well i bit the bullet and took the pipe off and cut it open to clean it out, the packing was smouldering quite a bit by the time i had finished so i was glad i decided to do it. i cleaned it all out and repacked it and welded it back up, and so will have to wait until next weekend for a test run.Im very glad i didn't burn it out 

Why are you glad you didn't burn it out?

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hi feetupfun basically my thoughts were that it is packed for a reason and burning wouldn't remove the wire wool that is in there so you would end up cutting it anyway, plus it would be pretty smokey. cutting it was a lot cleaner.

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6 hours ago, deputy dawg said:

hi feetupfun basically my thoughts were that it is packed for a reason and burning wouldn't remove the wire wool that is in there so you would end up cutting it anyway, plus it would be pretty smokey. cutting it was a lot cleaner.

Wire wool? Thought you only used fibre glass wadding in the exhaust. Wire wool has a tendency to break up into smaller pieces and could get into the cylinder, not good.

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12 hours ago, section swept said:

Wire wool? Thought you only used fibre glass wadding in the exhaust. Wire wool has a tendency to break up into smaller pieces and could get into the cylinder, not good.

Some Spanish bikes in the 1970s used wire wool as I discovered when I repacked my Cota 348 exhaust. The original arrangement was well designed with virtually no chance of causing problems. Yes I used some SMF to replace it

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