5.0 L stalls - Maxum Boat Owners Club

jayesq · 05-29-2012, 02:03 AM

I have a 1999 SCR 3000 with 2005 twin 5.0L. Boat started up fine after de winterizing. Ran fine on the day I launched it and put it in the slip. This weekend I went down to start it and I am having problems with the port motor. The motor starts and if I continue to rev the engine and bring it down to idle and keep repeating that it will continue to run. However if I set it at a specifice rpm after about 30 seconds it dies out. I noticed that when watching my fuel gph meter that prior to it stopping the gph continues to drop down until reaching 0 and then in a couple of seconds it stalls. I then have to wait at least 30 minutes to restart. Any thoughts or ideas is appreciated.

jayesq · 06-12-2012, 08:37 PM

Just wanted to close out this post for future reference by anyone. Turned out the problem was a defective oil pressure safety switch. The power for the fuel pump goes through this switch, so when in fails to detect oil pressure it shuts off the fuel pump. Here there was oil pressure but the switch simply went bad. Replaced the switch and ran the boat for 3 hours this weekend with no problem.

seapuppy · 06-13-2012, 01:30 AM

Thanks for the report out!!...good find..

SP

markwin1 · 06-13-2012, 02:03 AM

Funny, I was about to post a problem with my 5.0. Sounds similiar, engine runs fine, but on occasion at slow speed I get the warning alarm for low oil or engine over heat or transmission hot. But when I bring back to idle it goes away. Then will return at a later time. Have check all gauges and fluids and all seem to be fine.
Defective oil pressure switch??

jayesq · 06-13-2012, 08:41 PM

Mark,

Is the temperature gauge normal when the alarm is going off? I had it happen and I had clogged water pickup and I think it can also happen if you come down from a higher speed and you wind up with an air pocket around the water pickup and the engine starts to heat up because no water is being sucked in. I'm not sure of the technical terms. With my oil switch there was no alarm apparently the low oil pressure sensor is hooked up someplace else on the engine and my motor would completely shut off with the bad switch.

markwin1 · 06-14-2012, 04:42 AM

Thanks, I will check it out. FYI, Spent my summers in Brigantine, NJ, love it back there.