MC 197 Indmar fuel problem

[LeonL]

A guy at our lake has an '09 MC 197 that is making oil.  Actually fuel is getting in the crakcase.  Last week we drained that oil and got over 2 gallons out of the crakcase.  Has anyone else experienced this and if so what is the root of the problem?  The dealer said Indmar recommended replacing the fuel pump and they did that but to no avail.  Their next approach (per Indmar) is to "clean the rings".  It seems that the ideas from Indmar are pretty much from "left field" so far.  After a of download of the computer showed that out of 187 hours, 111 were at idle they said the boat wasn't getting enough normal running.  To the uninitiated that may seem odd, but not for tournament type skiing on a small private lake.  Hasn't been a problem with any other boats on our lake over the past 15 years.

[jdarwin]

Malibu boats (Indmar Monsoon Engines) suffered some similar issues.  It was determined that the fuel injectors were not shutting off when the engine was turned off. There was a small amount of fuel still being shot into the cylinders and therefore, leaking past the rings and into the crankcase.  This may be the issue.  Indmar is well aware of this issue - they replaced 4 engines that I know of in 2005/2006.  The Monsoon engine had a Cutler EFI system - I believe MC engines are all GM components but I may be wrong.

[LeonL]

Jody,  are you out there?  Is so what's your take on this?  Can stuck/staying open injectors put a quart of gas in the pan in 4-6 sets?

[RichardDoane]

Open injectors flooding cylinders will definitely fill up the crankcase fast.  Even if the mixture is too rich (over fueling) you'll get crankcase contamination.  With a fuel pressure gauge attached, you can check leakage (system pressure loss) over time with the key off.  My first guess would be an ecm problem holding the injectors open, and second would be testing the signal from the CTS (coolant temp. sensor).  There is also just the chance of leaky injectors, so sending them to a "Dr. Injector", or anyone with a flow bench/injector cleaning equipment would be a good place to start.  It's not hard to remove the injectors and have them tested.