1996 Mercury Force 25 HP Service Manual 90-830894 895, Page 61Get this manual
ACAUTION If cylinder block is to be submerged in very strong cleaning solution, it will be necessary to remove the crankcase cover bleed system check valve from cover to prevent damage and check valve
1Use bristle brush and carbon remover solution to remove carbon from side surfacesA tool can be made for cleaning the inner diameter ofthe tapered ring groovesThe tool can be made from broken tapered piston ring with the side taper removed to enable the inside edge of the ring to reach the inner diameter of the grooveCarefully scrape carbon from inner diameter of ring groovesCare must be taken not to damage the grooves by scratching the side surfaces of the groovesPiston with one half keystone ring and one rectangular ring2
Cylinder BoresInspect cylinder bores for scoring, scuffing or transfer of aluminum from piston to cylinder wallScoring or scuffing, if NOT TOO SEVERE, can normally be removed by honing
Pistons and Piston Rings,: CAUTION ",