Originally Posted by Compass790
Be aware these are raw water
cooled engines so they dont get hot. The thermostat opens at 52oC. Highest oil temp I've seen is 59oC.
Follow directions in manual for checking thermostat.
If its blowing white smoke you should check injector & compression
What is your oil pressure?
A common problem is the rotor to wear down into the case making the clearance btwn the rotor & the cover too large. Follow the instructions in the service manual to check the tolerances. If its out of tolerance PM me or post back on here & I'll give you some options for fixing.
Yanmars cure was to buy a new PTO case for $720+tax.
The crank main bearing on the flywheel end is a kings ransom too so you hope that is not the problem. Think they about US $400.
I got replacements
machined up to avoid the Yanmar extortion network.
I hope it's nothing serious on all fronts!
White smoke: the first time I saw it was when the weather
was getting colder. How do these engines handle cold cold water? It was snowing by the time I pulled the boat. I was wondering if the thermostat is designed to only close so much to ensure that there is always water flow, even if the temperature of the raw water is cold enough that flow would need to stop for the engine to warm up. Which of course would cause many other terrible problems.
Oil pressure: I need to measure the actual oil pressure. All I know is that at idle, the idiot gauge/alarm made a little squeek with each rotation of the engine. Rotating the filter makes no difference. I cleaned the filter at the last oil change
too. Bumping up the Rpm
"fixes" that squeak. However just before my last trip out (which was supposed to be to Florida
lol) I had to replace the throttle control. It's totally possible I just have the idle too low, I only did that by ear. A new engine would have bad oil pressure if idled too low. I've been thinking that an analog pressure and oil temperature gauge would help my peace of mind also. Do these engines benefit from adding an element oil filter? I've read that some people have done that but the Yanmar manual quoted some impressive micron level of filtration (forget the number).
In general I have the yanmar manual, but I only had the energy to put the boat to bed
and nothing more. I did nothing to try and and DX any of this according to the manual.