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white smoke on 74 dt 125


donny o
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Got my 74 dt 125 running but pretty smokey--white smoke. So is that too lean? Everything seems to be working okay--but I really don't know how you test the autolube oil pump. I check all the adjustments per manual but still don't really know if it's getting the oil needed. I want to keep it stock --as in I don't want to pre-mix. Just wondered if anyone knows how to diagnose smoke and if there is a test of some sort to see if oil pump is working . Thanks!

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Got my 74 dt 125 running but pretty smokey--white smoke. So is that too lean? Everything seems to be working okay--but I really don't know how you test the autolube oil pump. I check all the adjustments per manual but still don't really know if it's getting the oil needed. I want to keep it stock --as in I don't want to pre-mix. Just wondered if anyone knows how to diagnose smoke and if there is a test of some sort to see if oil pump is working . Thanks!

If you set up the pump correctly or verified adjustments including the cable slack in both the carb slide and the oil pump.

You can run some premix in your gas tank @ 32:1 then remove the oil line from the cylinder and install a screw back into the hole, don't use the oil line screw as it has holes in it. Start the engine and at idle you should see oil appear and thats about it. Rev up the engine some and you should see the oil start to move. Don't expect to see alot of oil move but you will see it. If you bike is smoking it is getting oil. To be safe if you want, you can ride the bike and slowly reduce the amount of oil in the premix until you are back on straight gas in the tank. Check the spark plug to make sure you not getting lean but I doubt you will see that. Also watch you crankcase oil level to make sure your not sucking oil out into the crank.

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White smoke,,could be the crank shaft oil seal gone ??

How long has the bike been stood ??

Quite a while--a year at least.. Where exactly is the crankshaft seal? Does the seal go bad from sitting or does the bike smoke from sitting?

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The main crankshaft oil seal stops the transmission oil getting in to the crankcase and thence into the combustion chamber, this some times happens if a 2 stroke engine has been left standing for a long time, the seals tend to harden and go brittel,, this would need a full engine strip to put right,,

Check the gearbox oil level, if this keeps going low and you have no leaks then this could be the reason.

Check the oil pump is set up OK. Accumulated oil deposits in the exhaust system could also cause the same problem, the system may need a good clear out !!

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  • 9 years later...

No need to split the engine to fix the oil seal,  remove the clutch basket, then the primary gear,  then pull the old seal out, [ self tapping screws into the old seal walls. and pull] ..  some models have a o ring on shaft also,  . then  push in new seal with a deep socket,,

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