Good news is that the A4 starts-up faster than you can release the starter button, plugs are dry (but a little sooty) and a mechanic tested the compressions at 125,125,120,125

OK here is the bad news .. possibly.

1) There seems to be a little blue smoke and a little sheen in the water .. so she seems to burning a bit of oil. The mechanic suggested that the oil rings might be worn and letting too much oil onto the cylinder and that would also explain the increased compression levels.

2) She is overheating when we take her over 40-50% power. This is something new for this cruise. I took the boat out 2 weeks ago and the engine ran and cooled fine. We aren't sure, we think that maybe it has something to do with having her pulled, power washed and a little scraping on the intake .. that maybe some sizable "chunk" of something is lodged somewhere.

Here's some other "tidbits"....

- The engine seems to pump less water as it starts to over heat. My theory on this was local hotspots causing stream and creating both a back pressure in the system as well as a "vapor lock" effect .. making the pump less effective.

- The mechanic says that it looks like the by-pass has been taken out of the system and that it is 100% drawing raw water thru the block. Since it was just an engine survey .. he didn't take the themo housing apart.

I am ordering Moyer's book today, so that I can have some understanding of what's what and where things are supposed to be.

I was thinking about doing the following as 1st steps:

1) removing the thermo and all cooling hoses I can easily access and check for blockage/operation. Clean and clear as necessary.
2) removing the pump impeller and checking for restriction or damage
3) re-piping the system back to normal by-pass cooling (if in fact it is modified).

Other 2nd'ary steps I was considering ..

4) Acid flush (or other recommended cleaning agent). I've heard Oxalic Acid, Muradic Acid and I've heard there are flushing products on the market specifically designed to do the job and also "do no harm".

Thanks for any advice in advance

Ang