2001 130 TXRR bad piston

[bigdummy]

Good Morning all. A few weeks ago I inquired about compression readings for this motor. I bought the motor because it is extremely clean corrosion free (appears to have been a fresh water motor) and is the perfect fit for a project I'm working on. I assumed it would need some work and figured if it needed complete rebuild it is still a good value for my needs- that premonition has become a reality.

Compression is low in one cylinder (50 psi) all others at 110 psi. Pulled head this morning and the piston/rings are toast in that cylinder. Looks like it was probably caused be carbon buildup. Cylinder wall has relatively minor scoring (for amount of piston that is missing) but will definitely need to be bored. This will be strictly a "leisure" engine, won't be running long distances, carrying heavy loads or high performance (basically 10 minute ride to sandbar or drift fishing for flounder)

I seek your knowledge and advice for the following:
If other cylinders and pistons are still within factory spec, must all be bored or can only the one scored cylinder be oversized?
Is there a brand preference for piston and rings?
Combustion chamber (head) is dinged from flying debris. can this be polished out or must head be replaced?
I am in mid-atlantic region- is there a recommendation of a machine shop that is experienced in outboard motors? Unfortunately I have discovered not all machine shops are created equal. Don't mid driving a few hours or shipping block if needed. Leaning towards finding a :"racing" shop with the thoughts they've blown up enough outboards to know what to look for.

I want to Thank everyone in advance.

[rodbolt17]

ron's marine in Portsmouth va or Carolina machine and tool in Wilmington NC. stay away from most auto or "racing" shops.
yes it is acceptable to oversize one piston.

[boscoe99]

I am in mid-atlantic region- is there a recommendation of a machine shop that is experienced in outboard motors? Unfortunately I have discovered not all machine shops are created equal. Don't mid driving a few hours or shipping block if needed. Leaning towards finding a :"racing" shop with the thoughts they've blown up enough outboards to know what to look for.

I want to Thank everyone in advance.

Like mechanics, they are all equal. It is just that some are more equal than others. You want to stay away from the less equal.

Hard to differentiate between the two at times.

[rodbolt17]

most automotive machine shops cannot properly chamfer the ports after boring.
it is tricky and done by hand.

[bigdummy]

Thank You, good information.
I will check with Ron's as I will be traveling near/through Portsmouth several times this spring.

Is it customary to disassemble powerhead (being careful to label locations of pistons, rods, etc) or to strip powerhead of all ancillary equipment and let machine shop disassemble internals?
I can mic the parts, but would like a second (professional) opinion on my interpretations.

[ausnoelm]

Most shops will prefer to do the work they spe******e in, machining! but some will do mechanical work too, for a fee!

[ausnoelm]

Now that's strange, a simple common word is removed!

[pstephens46]

Now that's strange, a simple common word is removed!

Where in the hell have you been? Busy policing the fools at THT?

[ausnoelm]

Haha, no, just doing other "stuff" THT is more a laugh these days, it's hardly worth asking an actual question there.

[ausnoelm]

Going to try the word again, spe******e!

[ausnoelm]

Wonder what's wrong with saying someone is an expert in a process, as in a special.........ist. Or spec.......ialise.

[bigdummy]

I knew what you were conveying.
Maybe the PC police think a "spe******t" in offensive in today's society!

And I must agree about THT. Stopped visiting THT a few years ago, stumbled across it again a couple months ago. That place is even worse than before.

Really makes one appreciate a place like this

[ausnoelm]

Yep, fully agree, a long time ago, THT was a great place for info and banter, now it's simply a place to argue, sorry to side track this thread!

[zenoahphobic]

Before you go to too much trouble engaging someone, is it possible for you to measure that damaged cylinder if it actually needs a rebore?

This would be better done by honing it slightly first if you know how to do that.

You could also use one of the good piston rings and observe the comparative gap and it's change at various position in the bore.

What's also helpful is using that good piston and seeing how it comparatively "rattles" in that damaged bore to its existing bore, even using a flashlight to see light through the sides of the piston before making a decision on reboring. Then you may only need one kit of the same rings and a new Std. piston.

Just a thought, seeing you are not demanding top performance, you can then engage a "lesser" and maybe more available professional. I would also not worry about the head chamber pitting if that is not excessive.