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Old 01-03-2011, 07:43 PM
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Unless you masked off the rings with tape to prevent particles getting into the ring lands you may have caused more trouble than you solved. Scotchbrite is too fine to do any kind of bore prep other than cleaning the surface which is what it sounds like you were doing.

The problem is the particles are abrasive mixed with a plastic matrix and if that gets into the ring lands or worse inside the motor it can cause a lot of damage...especially to the bearings which are soft.

If you just did one cylinder I would remove the piston from that bore and clean the piston and ring assy well with solvent and blow it out, a wipe of the cylinder bore is probably all you need since the particles won't have found their way into the lower end. You will likely find a lot of particles in the ring lands so pay special attention to this area.

The main issue with Scotchbrite is its a lot like sand when it breaks down and unless your careful it can easily get where you don't want it. I have even seen melted scotchbrite plastic foul a ring land once because the owner thought doing the bore like you did wouldn't hurt anything...of course he sprayed the piston down with contact cleaner which sent all the particles down to the first and second ring lands which made a mess. This was on an air cooled snowmobile so the damage wasn't catastrophic but the melted scotchbrite seized the rings in the lands and the motor lost all compression on that cylinder. I had to replace the piston on that engine because the ring was so tight I couldn't get it out of the was like the plastic scotchbrite particles and abrasive made the ring a press fit once exposed to the heat of combustion. Luckily the bore was fine but it could have been much worse if it had happened at high rpm instead of idling in his driveway at which point he brought it to me.

Clean out the mess before it gets worse, it doesn't take long to pull a newer piston to clean it out since there is likely no ridge yet...pull the pan and do yourself a favor by not rolling the dice. Leaving the particulate in there and starting her up is like russian roulette...she might seize...she might not.
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