Cutting off after a few minutes

RyalsCreek

Cadet
Joined
Jun 21, 2007
Messages
20
I have a Nissan 40. After starting, it runs about 5-10 minutes and cuts off and will not restart until about a half hour later. I think I may have got some mud or debris in the cooling area since I'm in shallow water frequently. I can see the a stream coming out of the telltale, but is it possible that it's partially clogged? Will it eventually pop out? I've considered sticking a heavy mono-filament line in to probe it.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Which Nissan is it 2, 4 strokes, 2, 3 cylinder OB ? ?

Runs 5-10 minutes and stalls at which throttle setting ? Could be anything electrical related, heats, shorts, cools down, engine starts again to die latter, the story goes forever. How old is that OB, is it used in salt water ? If so, is it being flushed after its use ? Running a wire up pee indicator won't do a thing.

Happy Boating
 
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TOHATSU GURU

Admiral
Joined
Jul 22, 2004
Messages
6,164
Since the stream occurs after the water has cooled the engine it is unlikely that you have a cooling issue....Unless the stream is so small that it indicates a lack of water. So cleaning out the pee hole will not help cool the engine at all. If the engine is overheating you can tell by placing your hand on the engine block while the engine is running. If the heat is unpleasant but you do not blister the engine is not overheating. If you lose skin and start screaming...Well that's an indication that you are running hot.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Yep, an extremely overheated engine as when impeller is shot or lower leg has catched a plastic bag, banana peel besides burning your hand will see smoke comming from under cowl, see scorched cables, melted plastic parts near powerhead, blown cylinder gasket and even bending cylinder head. A real horrible scenario.

If you think having an internal clogg, remove thermo, connect a garden hose on port hole, flush at high pressure for at least 5 minutes to free all water passage clogs. if thermo is extremely salty?, rusted, install a new one including thmo gasket. Engine will cool much better.

Happy Boating
 

RyalsCreek

Cadet
Joined
Jun 21, 2007
Messages
20
I?m in saltwater, on a shallow tidal creek with mud and silt until I get to the waterway. I just had it fully serviced a month ago, it was running fine for a few weeks, unfortunately, my mechanic is on a long vacation currently. He told me that he replaced some time of sensor in or near the shaft, an overheating cutoff sensor I believe he said. It?a about a 15 year old motor, 2 cycle. It ?s been cutting off when slow in a no wake zone and when going fast. I ran it yesterday on the dock at mid idle for about 20 minutes and it seems better. I?m hoping it was some kind of debris that worked its way out. I?ve heard other people on the creek mention having problems when coming back at low tide and sucking up debris from the bottom. I do recall distinctly on the day it began running poorly that there was a low tide and I was running in mud for several seconds. Thanks for all the tips, I?m going to try it again today. I?ll leave on a rising tide so I can drift back if it cuts off.
 
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