I purchased a 1991 mazda b2200 2wd 4cyl 5 speed and it smokes really bad on start up and uses a little oil. I know the previous owner and he said he parked it for over a year and when he started it up for the first time it smoked bad ever since. it has 162500 miles on it. Runs great,good power. Could it be stuck oil ring or more likely valve stem seals? The smoke clears up after 5 minutes, I am thinking the seals dried out after sitting for a year.

 

Agreed. It would be best to replace the valve guide seals but you could try a high mileage oil like Catrol GTX high mileage oil. It has additives that can expand seals and fill in microscopic cracks. But once you use that stuff you need to stay with it.

 

replaced valve seals, still smokes. Truck runs great. seems to have decent power. Compression is around 110 all around. rings sticking?

 

If a ring is sticking it should have affect compression at least a little bit. Still it is possible that a ring is stuck. But that should resolve over time by using quality oils and adding something to it. (Seafoam=Naphthalene, or Zmax a microlubricant).

But what if it is not a stuck oil-ring? Maybe we can figure it out:
What color is the smoke? Does the amount change with engine temperature, engine speed or anything else you can observe?
How do the spark plugs look?

 

plugs are black. not oiled up. smoked is blue/white ( not anti freeze i monitor it and have to add oil. When choke is on it smokes more. when you punch it it will pour out. after an hour or so it will show 0 sign of smoking. air filter is not covered in oil.

 

110 compression seems low to me. With air pressure being 14.7 pounds per square inch (standard-universal), that would lead to a compression ratio of 7.48:1 currently in your vehicle. Don't think Sea Level is a valid point here, doubt it very much.

The 1991 B2200 comes with two different engine options. The first is a 2.2-liter, in-line, four-cylinder block. The engine produces up to 85 horsepower and 118 foot-pounds of torque. The engine's bore measures 3.39 inches and stroke 3.7 inches, while the engine's displacement is 2,184 cc. The engine's compression ratio is 8.6:1. The second engine is a 2.6-liter, in-line, four-cylinder block. The engine produces up to 121 horsepower and 149 foot-pounds of torque. The engine's bore measures 3.62 inches and the stroke 3.86 inches. The engine's displacement is 2,606 cc and the compression ratio is 8.4:1. Both engines come with a four-speed automatic transmission that has overdrive.
I thought the compression ratio would be higher from factory, oh well.

 

Black plugs could be caused by a rich mixture condition. Blue smoke is definitely oil. The compression numbers are even, which is more important than the absolute number. But you should be able to find the absolute number in a Haynes manual.

My best guess: the smoke is caused by sticking rings. But there may be another way for oil entering the combustion chamber: head gasket. Some head gaskets have to let oil up into the valve train and seal the passage canal off. It may fail when cold and seal again as it expands.
Maybe you can find some pix of the proper head gasket and confirm or exclude that idea.

 

12 months ago I replaced the pistons (NPR), rings (NPR), connecting rod bearings on my 1988 B2200 with 183K miles, with all standard size. The only machining was having the cylinder head re-done, and new valve stem seals. I did this all to fix my smoking problem, and I had 165 psi compression in each cylinder before the rebuild, and it still smoked. My oil control ring on each piston was stucl in the piston groove, like it had lost all its springiness.

My connecting rod journals and old bearings looked perfect. I didn't even look at the main bearings.