Mariner Magnum 40--How Hot is too Hot, Fry an Ignition?

gloveral

Cadet
Joined
Jun 17, 2006
Messages
26
Took my mariner magnum 40 project to the lake today after successfully transplanting it onto my boat and replacing all of the electronics. It seems to be running hot.

The motor pumped water, but it took about 5-10 seconds for it to make it out of the tell tale. However, the stream was strong and heavy.

Pumped well throuh idle and still at WOT and all ranges. After about 10 mins of operation the motor started to surge. Seems like it was losing 2 cylinders. I brought it to idle and there is quite a bit of steam coming out of the upper exhaust and the water out of the tell tale was HOT.

Water did not immidately steam off of the motor (my usual back woods check) but it just seemed hot--even the flywheel was hot to touch.

I must confess I did not change the impeller and that is my next move so that could be part or all of the cause no doubt--should have done it to begin with but the stream was so strong once it started.



Here are the quetisons.

1. Does this motor have a thermostat that could be stuck
2. Should it take so long for the water to start pumping
3. Should I be seeing all of the steam after running WOT and coming to idle

4. Could it have gotten so hot it burned up my new trigger and power pack to cause it to drop cylinders

Timing is set to 3 degrees ATDC at idle and 32 degrees BTDC full advance/throttle at cranking speed with plugs out. Carbs are adusted to the rich side and I am running double oil until I can verify my oiler system is working.


Thanks for the help
 

GDiamond

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Joined
Aug 28, 2009
Messages
11
Re: Mariner Magnum 40--How Hot is too Hot, Fry an Ignition?

When you say upper exhaust, that is only exhaust not water too ? I'm having the same problem. I posted today with the 1995 Mercury 40hp 2 stroke (4 cylinders).
 

gloveral

Cadet
Joined
Jun 17, 2006
Messages
26
Re: Mariner Magnum 40--How Hot is too Hot, Fry an Ignition?

I am calling the two holes in the tower just under the belly pan/power head the upper exhaust. I am getting some smoke out of there upon acceleration due to the heavy oil but just getting steam out otherwise, not seeing any water out of those holes. I get some water out of the prop when I start on muffs and also out of the tell tale, that is it. I will search for your post--as well. Mine is a 4cyl model as well (2 stroke)
 
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