Ron White wrote:
speed , without oil system pressure . Now one BIG issue. DO NOT premix as a
substitute for oil injection, your engine will blow up, this is not a maybe
it WILL. Reason is the Optimax as well as other direct injection engines (
Yamaha HPDI and Evinrude Ficht) have the fuel injected into the combustion
chamber, is does not go thru the crankcase, so premix will only lubricate
the piston and cylinder walls, no oil will ever get to the main bearings and
rod bearing and case seals. No matter what you are told don't believe it, it
just ain't so.

This makes perfect sense, but what's discouraging is the guys who
vetted premixing are the same horseshoe bay boat centre people whose
mechanics service the engine!

As far as why oil could have got low in the reservoir , it could have a
cracked cap, cracked tank or leaking hose or even a leak of pressure at the
main oil tank or maybe even the pressure pulse to the remote tank is missing
( bad check valve leaking hose or cracked oil tank or that cap may be loose
or cracked), other than the caps these are not so common but are all
possibilities. So don't overlook carefully checking out the whole oil system
to see that it is pressuring up. Your idea on the sender is good, to
troubleshoot that too, disconnect it and if it is still alarming then short
between the sender wires, either open circuit or closed will be the
condition the computer is looking for to say, things are ok. You have a good
engine and this is a simple problem for now so get it fixed right.
I hope this helps, good luck,

I did make it home without problems, so it's virtually sure the
fault was with the probe itself. The boat centre guys ended up
replacing the whole internal resevoir, though. Not sure why, I
couldn't see any leaks, but at least the problem's gone now.

For further worry, the boat centre says this is actually a former
"camp boat" engine. There was no mention that it had been
refurbished at point of sale, and standard break in procedure was
advised and followed.

Is there any way I can tell if they're blowing smoke, or if Mercury
really does this? Or is it just that everyone associated with boating
around Vancouver is a crooked swindler? Probably you're not in a
position to answer that one, but sometimes it really seems so.

Thanks for your help!


Ron White
Boat building web address is
www.concentric.net/~knotreel