bore or not to bore

[haz]

1994 johnson 40 hp, M/N J40ELERE<br /><br />After a light "clean-up" honing, my cylinders measure about 3.185". I was wondering what the stock specs should be? Maybe this thing has been bored once already? Looks like the piston skirts measure up at 3.180"-which seems pretty good to me (0.005" cylinder/piston clearance). Do you think I can get away with just new pistons and rings?

 

[Dhadley]

Re: bore or not to bore

Standard bore on those motors is 3.1875" and I'd be willing to bet that your cylinders haven't shrunk. <br /><br />The expensive part of your decision is the cost of the pistons. Boring is relatively cheap. If youre going to buy 2 new pistons anyway, go ahead and bore the block to .020 over.

 

[stairliftoheaven]

Re: bore or not to bore

doin just that with my 1985 rude 60.same bore size & rebuilding the motor myself. wil llet ya know how I get on. block with the machine shop at moment. DHadley fountain of all knowledge so I'm glad I'm here!

 

[haz]

Re: bore or not to bore

OK, you've talked me into it. I'll take it to the shop tomorrow.