Scoring

[Boston Habba]

What exactly does scoring look like. A couple of my cylinders have darker lines on them but they feel smooth and you can't feel them when you run a fingernail over them. One has a line that you can just feel with your nail.<br /><br />Thanks

 

[Boston Habba]

Re: Scoring

bump

 

[The Marine Doctor]

Re: Scoring

Scoring you can feel with your finger nails. The darker patches you can see is where the cyl is worn, the cross thatching is gone. Sounds like time for a rebuild.<br /><br />TMD

 

[Boston Habba]

Re: Scoring

This engine (V175 1987) has chrome bores so it can't be honed. Have to bore and sleeve. Only one cylinder has scoring and only one barely detectable line. The compression is good. I'm only planning on running it for a season or two. Is it really necessary to bore and sleeve or can I close it up and run it?<br /><br />Pistons and rings seem to be OK.<br /><br />Thanks

 

[Kenny Bush]

Re: Scoring

If it cleans up OK, get a new piston and run it. My definition of scoring, is when the piston is damaged and leaves aluminum ground/melted onto the cylinder wall. Most scored cylinders have damaged pistons that will need to be replaced.

 

[Boston Habba]

Re: Scoring

What I am seeing is not aluminimum deposited on the wall but a small scratch. I removed the exhaust cover and looked at the piston. It looks fine. I'll look closer tonight.

 

[Kenny Bush]

Re: Scoring

Have you done the Acid test on your chrome sleeve to see if it reacts with aluminum under the sleeve(Bad). If it does, you will need to resleeve, it it does not, I would clean it up and go. I would pull that piston out to see and clean any damage. If you pull the intake plate off, you can get to the rod cap and pull that one piston. Leave the carbs and everything on(It will save time). I could pull the Piston and reinstall in about 1.5 hours. I just hope that scratch is not a very deep groove........