Optimax High RPM Overheating?

[Salty Dog]

Twin 2001 Opti 150. Ser # OT274461 and OT274141


I pulled a friends boat off of a sandbar and loaded up my engines with crud.


I did the complete water pump and t-stats. I went to change the poppet valve and someone had removed it so I left it out. In the process I tried to remove the grommet and I fell into the block I hope that isn't the cause of my problem.


I also cleaned the strainer but I'm thinking I should do it again just in case and stick a shop vac into the hole. The water pressure is much higher than the starboard engine so something is restricted for sure.


I have the Smartcraft gauges and the analog also. The temp of the Smartcraft stays cool but the analog will hit the red and sound the alarm.




Any ideas guys?

[Ski]

If your getting an alarm your defiantly overheating, funny that the Smartcraft isn't agreeing.

It's just a thought but how about dropping the lower unit and hooking a hose to the water tube and giving the motor a good flush? I would also consider flushing back thru the t-stat housings. That grommet in the motor isn't going to help you later.

[Salty Dog]

I don't think the whole engine got hot, just the compressor. The Smartcraft gauge showed cool while the analog got into the red.

I flushed everything out and it seems good at the dock. I'll take it for a run tomorrow. There was a poppet in there but someone removed and plugged the hose that goes up to the top of the block. I put the hose back in place.

Id rather not pull the powerhead until last resort, i just need to find that damn grommet. Will it fit through the exhaust plate? Has anyone seen a bare block from the bottom to see if the poppet grommet will get washed through or get stuck?

[Salty Dog]

I went for a test ride and it seemed ok but low water pressure and high temp at idle.

Someone had removed the hose that goes from the poppet to the top of the block and plugged the ports. I reinstalled the hose and I think it might be my problem as the starboard engine is still plugged and has better pressure and runs cooler.

Was there a reason these hoses were plugged? Maybe Merc decided it was necessary? Anyone heard of this?

[Salty Dog]

She's running cool at high rpm but has low psi at idle. Should I remove the pressure relief hose and put the plugs back in?

I read somewhere the the hose should be restricted down to 1/8" what do you think?