Topic: '71 K0 #3 Cyl Smoking

[Sjohnsone]

Hello everyone,

My 71 K0 #3 cylinder began smoking last week.  I'm guessing it's probably a valve guide or piston ring.  At the moment I don't have the money to fix it, but it's my daily transportation.  Are there any issues with me just continuing to put oil in it and running it or am I sort of playing russian roulette every time I start it up?

At the moment it isn't necessarily billowing clouds of smoke, but it is visible regardless. 

I was told that putting a heavier oil into it could cut down on the smoke.  Will this work? What should I use?

I already know that most people will say it needs to get fixed - it just isn't an option at this juncture.

[wrenchmuch]

Is it running differently ? Could the smoke be un burned fuel ? Is it using more oil than before? If it is an internal engine problem 20-50 oil might help. Exhaust valve guides it the early engines have no seals. It's unlikely that the guide would suddenly begin leaking more. A broken ring would cause increased oil consumption. Running with a broken ring is going to cause damage to the cylinder walls at the least. Can you check cylinder compression?

[Sjohnsone]

To be honest, it really doesn't seem to be running all that different with the exception of smoke now. It's just that one cylinder too.  I have no way of doing a compression check myself.  I'm assuming though that I could sort of figure out it's a ring if I put heavier oil in and it stops smoking.  The oil doesn't appear to be getting consumed any faster than it did before.  It also doesn't start smoking until it has run for a little bit - about 10 minutes of riding or taking it on the highway and it starts coming out in puffs.

I brought it to a mechanic who looked at it for about 30 seconds and said he thought it was valves or rings and that it would cost me about 1400-1500 to get it fixed.

[wrenchmuch]

Check your plugs. Are they consistant with one another ? Excessive oil use will
show shiney black on the plug. Compression gauges are cheap and can give you insite into engine condition.