Motorcycle Repair: 1981 Yamaha 850, excessive blowby, clutch cable

Question
I have a 81 yamaha 850 that was running a little rough.  Last fall it would leak gas thru the air filter when parked on an incline, not if it was parked level.  I was riding it home, 2 miles and had a hard time keeping it running.  I started it a couple days later and after about 15 seconds of running I had approx a pint of oil on the ground .  I seems to have come from the air filter also.  I have not started it for a while since, figuring it was something major and dont have much money for anyone to look at it.  I was hoping you could tell me if you have an idea of what it could be.  Thanks in advance.. Rich

Answer
Rich,

-it sounds like the carbs may need cleaning
and possibly new float needle valves.
-The oil could be from the engine breather
tube that runs into the air cleaner box.
-If so, you may have some engine problem
causing excessive blowby, like bad rings,
blown piston or whatever.
-On the other hand it may just be a mixture of
the gas leak and breather oils dripping out of the air box.
-The best thing to start would be to
borrow or buy a compression tester, check the
compression and see if it is above 150 PSI,
and that all cylinders are near the same.
-If they check out, change the oil, clean
the air filter, check the spark plugs
charge the battery and see if it starts up.
-You may need to remove the carbs if they
still leak and clean them.
-Check the float valves for leakage. Replace
if necessary.

-Carb removal:
Remove Tank and loosen the carb clamps to the air
case and carbs..Loosen the breather hose at the air case
-Then remove the 4 bolts that hold the case to the bike
behind your side covers (Note the ground wire)
-Remove clutch cable from carbs holder
-Pull air case to the rear
-Lift carbs back and to the left
-Then remove throttle cable
-Do in reverse to put back in
If I recall if your air box has the air cleaner
down and forward low on the air box..
-Remove the wing nut and filter cover to
give some extra room to get the carbs out.
-If the rubber is hard it will be very
trying to get them back in. Use something
slippery to assist like "armour-all"