1988 OMC 4.3 weird stalling

Burninup9

Cadet
Joined
May 9, 2013
Messages
7
Hello all,

So yesterday I took my new to me 1988 fourwinns horizon 200 with the OMC 4.3L and cobra out drive for a test ride. Boat ran great coasting through the river at about 10mph. Once I got out of the river I opened it up and the boat was cruising great at 30mph for about 8 minutes, then I slowed down and was coasting back towards the river at 10mph again and the engine shut off. I immediately tried to crank the engine over and all I get is 1 small crank. The motor wouldn't turn over and it sounded like it was locked up. At this point I'm thinking the worst. I open up the engine cover everything seems normal, warm to the touch not hot, no smoke. I should mention now that through this whole ride the temp gauge stayed at 0 which made me a little bit nervous. So after inspecting the engine nervously for 10 minutes I decide to try and crank her again and she started turning over ! So I pumped it and gave her a little gas and she fired back up. Engine sounded good didn't see any issues at all. I was pulling my anchor up and was going to head back in but after about 3 minutes of idling the engine made a strange noise almost like it was gargling which lasted 2 seconds and she shut back down. I tried to start her up again and she turned over fine but took a couple tries to start back up which when she did I just killed the motor and called for a tow. 15 minutes later I tried again and she cranked reaaaaaaal slow then after 10 seconds of cranking she was locked back up. My tow arrived and we brought her back to the dock and I tried cranking her 1 last time and she fired right up and sounded great for about 20 seconds and then I shut her down and loaded her up. Anyone have any idea what's going on? I sure don't, this is my first boat. I'm thinking maybe it is overheating and that is why the engine seemed to lock up? Also the thermostat staying at 0 makes me skeptical, also at 1 point after the boat was sitting for 10-15 minutes without running I happend to look at the temp gauge and it was at 130 degrees and that was the only time it wasn't at 0... I'm lost anyone have any ideas?
 

Burninup9

Cadet
Joined
May 9, 2013
Messages
7
Does anybody know what thermostat I need for the 1988 OMC 4.3 can someone link me to where I can purchase one please
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,829
First:
is there motor oil in the engine?
is there drive oil in the outdrive?
because if either is very low, that might explain your locking up issue.
also, if your exhaust manifolds are bad, they could be putting water in a cylinder, which could cause slow cranking/locking up.
the thermostat is a 160 stat used on many OMC and Volvo models. Crowley Marine sells original OMC parts on line.
 

Burninup9

Cadet
Joined
May 9, 2013
Messages
7
Alright so I got to the boat today and I fired it up and after 30 seconds it sounded like junk metal on metal. I shut it down immediately and checked my engine oil - looked great - checked out drive oil from the top dip stick, bone dry. I drained the oil from the bottom and about 1 quart of light neon blue oil came out. I filled it up with Valvoline 75W90 high performance gear oil. ( Is this stuff good? Any recommendations I plan on changing it out again this weekend, also where can I get new o-rings for the drain, fill and dip stick?).

Anyways, after the new gear oil was in the engine seems to be running great on the hose, no weird noises. I even popped it into forward gear and everything seemed smooth. I'm hoping I am very lucky and avoided any damage. Now I know to never listen to the prior owner when they say "I just changed it before I winterized"
 
Top