HP 500 EFI Injection
 

One of mine (the one with the bad starter) has recently been making a very loud "hissing" noise when it is started cold. The noise appears to be coming from the intake plenum, and sounds somewhat like a blow-torch.

After 5-10 minutes, when the motor warms up, the noise stops. The engine seems to run fine then, although I've noticed that the oil pressure is now 10-15 pounds less than it used to be.

I'm wondering if it's possible for an injector to "stick', and if the reduced oil pressure could be a symptom of gas diluting the oil (although it looks and smells fine).

Any ideas?

After 4 years and 300 hours with zero problems, I guess my luck has run out. I blew a Bravo drive (the other side from the engine problem), and just got the boat back yesterday (with new XR upper gears) when the starter and "noise"/low oil pressure developed.

ttt

As they used to tell me when I blew my first drives (yes, I blew them both):

"Welcome to the world of offshore boating!"

It is an expensive hobby.

So: 4 years, 300 hours with Zero problems on an Apache is quite an achievement. See it positivly!

I would give the engine to service - I don't think an injector can "stick".

Vacuum Leak
 

The hissing sound is probably a vacuum leak that goes away when the engine warms up which means a gasket is travelling due to metal warming up and expanding/contraction. I would have a qualified mechanic review and the vacuum gauge will tell the story.

Wannabe

Apache 14
 

The boat I've had the terrific luck with is my Formula 382 with HP500efi's, not an Apache.

I never had luck like that with either of my Apaches, unfortunately. That's the main reason for getting the Formula: I simply got tired of limping home on one motor 3 or 4 times a summer.

Wannabe
 

Thanks.