Is my 1GM10 overheating?

[greggron]

I have a 1GM10 installed on my Sadler 25. It runs fine and I get water through the exhaust but when I run it above 80% revs (no rev counter but that's what it feels like) I get a burning rubber smell. I am not absolutely sure whether it is from the exhaust outlet or up from the engine compartment through the various hatches. There is no smoke from the exhaust but I occasionally get steam this time of year and early morning etc which seems normal.

It has been doing it for some time and I cannot relate its onset to any event.

Thoughts please/advice please

 

[Biggles Wader]

Alternator belt?

 

[Pleiades]

Your 1GM may have partial restriction of the cooling water circulation. Whip off the rubber cooling hose from the front of the engine and you may find the bore is very considerably narrowed due to build up of solid calcium like deposits - hence over-heating at high revs and excess steam at tick -over. Easy to re-bore or fit a new pipe.

Robin
Pleiades of Birdham
MXWQ5-

 

[greggron]

Thanks, I know belt is fitted ok and in good nick but I'll give it a sniff. She's coming out for a scrub next weekend and it's planned to flush out the cooling system and if necessary put in some descaler and leave overnight.

 

[TonyBuckley]

Strainer?

My 1GM10 (old boat) overheated cos the elbow was knackered. But that was the only time.

 

[blackbeard]

If it overheats you SHOULD hear a wail of protest from the engine as the temperature sensor senses temperature. Also the relevant light will glow.
If you think the sensor might be knackered, stop the engine and touch the cylinder head. If it's warm rather than hot, the engine isn't overheating.

Steam in the exhaust is generally bad news, but not always, exhaust going into cool and very moist air can give an impressive cloud even when the engine is operating normally. Disconcerting though

 

[greggron]

Strainer flows fine, no alarm (actually once a three years back when motoring at full chat for a couple of hours into a strong headwind), took elbow off last month and was fine.

 

[TonyBuckley]

Well you didn't say it was overheating just a smell of burning rubber.

I can smell that in my imagination, but perhaps it is not a burning rubber smell? What's your shaft lube like?

I'd be concerned you can smell in the cockpit. Sure its not 48 slices of toast cooking .

I always got steam/smoke at startup from cold btw. 1GM10s have a fond place in my memory though buggers to start in the very cold sometimes when alone.

 

[JumbleDuck]

Mine did that. The alternator bearings were on their way out, so as the engine heated up the alternator got stiffer and the belt started shredding. Of course by the time I went to investigate the thing had cooled down slightly and the alternator turned easily again.

 

[greggron]

Thanks! A line of investigation to follow