587 compression ranges

[pob245]

Hello, I have 1996 SPI with 587 rotax. Compression has dropped 20lb in each cylinder over the last 2 years, from 150 to 130. What are the normal ranges for considering low compression and high compression on these engines?

 

[Dr Honda]

130 is getting on the end of not running.

If it was my ski... I would replace the pistons, and rings before you have a failure.

As the rings give up, the blow-by will heat the piston skirts (and burn the oil away), and cause it to melt down. When that happens, it's a full rebuild. Right now... you could probably just swap some parts, and continue to ride that ski for 10 more years.

 

[pob245]

Thanks very much for the description and warnigns On low compression like this on these engines can you ever get by just replacing the rings and honing the cylinder with drill hone?

 

[Dr Honda]

Thanks very much for the description and warnigns On low compression like this on these engines can you ever get by just replacing the rings and honing the cylinder with drill hone?

Yes. BUT.....

When you take the pistons out... check the skirts. You should see small ridges in them. (around the circumference) These are left-over tool marks from the manufacturing process, but they help hold oil, and decrease the surface area in contact with the cylinder. If the pistons are worn smooth, I'd replace them.

 

[pob245]

Thnaks Again.

I didn't see much available for rebuilding on eBay. If anyone has link to good location that was in, or would ship parts to Cand that would be cool.