Motorcycle Repair: Oil change., honda cm400e, piston rings

Question
Dude me again.  Hey thanks for your help.  Due to the Overflowing problem was the Float pin was cluck with some junk or rust from the tank.  After i cleaned it with Carb cleaner and assemble it back its now not overflowing and running great.  Now,, here are some problem i have now.  I see some dark Oil coming out from the muffler. Is this normal?  Also,  this bike can't go behind 50MPH.  I change the sparkplugs and nothing really change.  What's next?  Thanks Falcon.

brant


Followup To
Question -
Wazzup Falcon. me again 1980 Honda CM400E. dude, how often you do change Oil.  I asked a mechanic about Oil stain around head toward exaust pipe and he told me that, Its normal for this bike because this is 26years old.  The gasket needs to replace but its not worth it do overhaul for this bike. Just enjoy the bike and maintain Oil change, but i did not ask him how often.  thanks falcon.

brant
Answer -
Hi Brant.

You should be changing the oil about every 2000 miles or every 6 months, whichever happens first.  The oil filter can be changed every other oil change without hurting the bike.

Get yourself the repair manual for exact specs.

Ride safe.
FALCON  

Answer
Hi Brant.

The oil could be coming from one or more of a couple of sources; and no it is not normal.

1) Oil is seeping past the piston rings and being blown out of the exhaust valves and into the exhaust pipe.  This can be determined if the plugs are oil fouled.
 The fix for this is a ring job.

2) Excessive oil is getting into the head at the exhaust side and being blown out the exhaust by the exhaust gasses.
Not too sure what the fix for this one is.

Get the bike into a shop to get it looked at if the problem continues.

Good luck and ride safe.
FALCON