rebore question

[bjf1280]

1 bad cylinder, already been bored to 20 over. Been told 40 is max, my qustion is can I go to 30 or 40 and still run safely and can just the 1 cylinder be done or do I do all 4. 1990 V4 90 evinrude

 

[emdsapmgr]

It is considered an acceptable repair to bore just one cyl oversize. If it will clean up at .030 oversize go for it. Just be sure to use the same type piston. If the other 3 are factory, get a factory oversize. Also, put new ringsets on all 4 pistons during overhaul. If you go over .030 over, you may want to rejet that side of the carb that feeds the oversize piston (.040).