Cylinder Bore

[BigB9000]

A neighbor of mine does cylinder honing, so I asked him to check the bore for me.
This is for my 1977 9.9 HP with a 1975 15HP Powerhead.

Top cylinder is okay, but the bottom cylinder is .003 out of round.

Also- I noticed a .030 stamped onto my pistons.
So Im guessing a re-bore is out of the question.

Think the 3/1000th of an inch out-of-round is going to be a problem?

Also, piston moves just fine in and out, just like it has a little bad spot.

 

[Daviet]

Re: Cylinder Bore

Did he check the bore at the top of the cylinder or were the pistons out of the block?
I have seen engines with that type of clearance run fine for a long time. Not much you can do about it if it has already been bored .030 over.

 

[boobie]

Re: Cylinder Bore

Why did you take it apart ?? What was the problem ??

 

[racerone]

Re: Cylinder Bore

There are lots of those blocks available ---try Ebay.

 

[Faztbullet]

Re: Cylinder Bore

Slap a set of Wisecos in it as they like the extra clearance...

 

[boobie]

Re: Cylinder Bore

See post # 3 ??

 

[BigB9000]

Re: Cylinder Bore

I bought it for $50 because it was seized.
I wanted to take it apart rather than trying to breaker-bar it loose.
Found a stuck lower crankshaft bearing, a failed lower seal, sand around the top of the driveshaft, bearing, and exhaust ports.
Doesnt look like sand did anything to the cylinders.

Everything looks pretty good?

Pistons were out of the block- block is completely disassembled.
I just set the pistons back in for storage.

Ive been debating putting the crankshaft and block back together as-is and doing a compression and/or leak-down test before spending the $100 on gaskets and bearing to see if it'll run and sound good.

 

[boobie]

Re: Cylinder Bore

If you do that you will have to buy a head gasket.