QUOTE (zakats @ Mar 25 2011, 05:56 AM) <{POST_SNAPBACK}>
Question: I would think that I should pull the pistons out and clean up the ring grooves then reinstall the pistons but I'd like to hear it from the guys that have done this sort of thing a few times to affirm that this is necessary- I really don't want to mess with it if I don't have to.
You definately should do that.
After years and years of use the oil rings tend to stick and fill up with carbon, including plugging the six pin holes in the sides of the pistons in the oil control ring groove.
Remove the oil pan and monkey a socket in there and remove the bearing caps. Pop the pistons out through the top and remove the rings and throw them away.
Clean the pistons thoroughly (hot tank recommended) and make sure you scrape out as much carbon from the ring grooves as possible, then, by hand, turn a drill bit into the crud that is almost guaranteed to be in those oil return holes in the oil ring groove.
After that, source out and install factory replacement rings to your pistons. Remember to space the ring gaps as per the service manual, and use the proper piston ring installing tool to have the rings tight to the piston when you tap them back into the holes. Before you install your pistons be sure to run a cylinder bore hone on a 1/2" drill up and down in the bores, about five or six even, rhythmic pumps up and down the bore to create a re-finished surface for the new rings to seat into.
Having done this several times on my old honda motors (with 350K+) I can tell you than replacing the rings and re-honing the bores will basically give you a new motor again. Restored compression, no more oil burning, and clean shiny insides will give the motor a new lease on life, plan to do the bearings and another set of rings after another 250K of service.
As far as relacing bearings is concerned, based on your mileage they probably won't need to be done. When you pull the pistons you will have a chance to inspect them, but as I said, even a motor with 350K has serviceable bearings. Expect to replace them after 500K of service.
Do the rings, you will be glad you did, and now is the time to do it.
Good luck,
Mark