G2 - Blue smoke - Out of ideas

[kingarthur]

Have a 1987 G2 that I bought used and have no historical information on maintenance.
It is blowing blue smoke out of the muffler, assuming it is burning oil.

What I have done so far:
Replaced air filter
Cleaned air box
Changed oil. Put in exactly 1 quart
Adjusted valves
Cleaned carburetor
Engine compression is at 152 lbs
Added oil to cylinder to test if I had bad rings. Compression doesn't change

Does anybody have any other suggestions of things to check??

Thanks

[cgtech]

The oil control rings fail, while the compression rings are still pretty good. Your scenario is the common mode of ring failure on those models. I have one that's just the same, but it's just a yard beater, so I'm not rebuilding it. Just know, if you are driving it, and it stops smoking, that's because it's out of oil.

[CP241]

Originally Posted by cgtech

The oil control rings fail, while the compression rings are still pretty good. Your scenario is the common mode of ring failure on those models. I have one that's just the same, but it's just a yard beater, so I'm not rebuilding it. Just know, if you are driving it, and it stops smoking, that's because it's out of oil.

cgtech, as usual right on point.

AS long as you keep oil in it, it will probably run forever. The oil control rings have nothing to do with compression, but when they break or stick you'll get the smoke show. Don't run it out of oil and it will last a good while to come still.

If you rebuild, pull it apart first to make sure it doesn't already have an oversized piston in it. It should be marked on the top of the piston. If your compression is good, and there's no scarring in the cylinder, you may be able to get away with just deglazing the cylinder and a new set of OEM rings. Stay away from the aftermarket stuff unless you want to rebuild it again in a year.

[kingarthur]

Thank you again for all your help.

[slonomo]

Try some Rislone ring seal or Restore

[raydhd]

Why ruin a good engine ? Not all that hard to pull the engine and do a minimal rebuild ? A hone, some rings, and some rod bearings should give quite a few more years.

[CP241]

Originally Posted by raydhd

Why ruin a good engine ? Not all that hard to pull the engine and do a minimal rebuild ? A hone, some rings, and some rod bearings should give quite a few more years.

What he said. 2-3 hours well spent.

[raydhd]

The rings,rod bearings,side cover and head gaskets come to $73. Add a torque wrench and clutch puller and maybe you are just over $100.

[slonomo]

Rebuilding an engine takes some knowledge. Most people aren't experienced enough to tackle that job. I agree that would fix it, and that's what I would do. Maybe the OP isn't comfortable with doing a rebuild, and understandably so. It's not something you just do without guidance, knowledge, and good mechanical ability. If the OP is pretty mechanically savvy, I'm sure he will be buying the rings and bearings.

[raydhd]

With youtube and our help anyone should be able to do one. Once the crank or the block is hurt it is kind of game over. Who knows he might a friend here or there to help him with the project. I just wanted to point out how little cash was involved in a minimal rebuild. Some people hear rebuild and think tons of dollars are required. One of my neighbors in cleveland tool his lawn tractor engine to the local high school with the parts where the reassembled it for a paltry fee.