1GM10 stalls when put into gear

greggron

greggron

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She starts fine - perhaps a bit slow but even when warm will stall when put into gear (more often when going into reverse than forward). Otherwise operates fine, no smoke etc. There is no rev counter so no idea if we are reaching 'full revs' when I open her up.

What could be the cause please?
 
Assuming it is shaft drive and not a sail drive can you turn the prop shaft reasonably easily by hand in neutral ? Is the idle speed to low ?
 
Propshaft turns fine by hand in neutral. Idle speed might be too low but sounds similar to 1gm10s idling on YouTube etc. no adjustment has been made to idle speed so cannot think why this symptom would have developed.
 
There are a couple of possible causes. Firstly, the injector pump may not be fully opening when you crack the throttle or the "stop" lever may not be fully home. These are fairly easy to check. The injector is inside a pre-combustion chamber and the holes in this might be choked with carbon. It's not a common occurrence but when I had my head off and the injectors out a couple of years ago the thing like a thimble with holes in that the injector nozzle sat in had to be renewed. If you don't have a flexible coupling and there is a measure of misalignment this will also give you a bit more load on the engine.

I didn't realise how marginal these wee engines were on power until I replaced my alternator with one a bit too high output. Your engine ought to be able to spin the gearbox on tick-over but there's not a large power residue and if it can't it could even be as simple as a badly fouled prop.
 
Yes - it was changed in March. could it really stall the engine when warm? I could understand if it was cold, but it stalls when the engine has been running under load for some time.
 
On my GM 3 30 it clunked when going into gear. That might be enough to stall a smaller engine. Turned out the throttle stop spring had list its resistance. It needed 900rpm. Easily fixed with a stronger spring.
 
greggron said:
She starts fine - perhaps a bit slow but even when warm will stall when put into gear (more often when going into reverse than forward). Otherwise operates fine, no smoke etc. There is no rev counter so no idea if we are reaching 'full revs' when I open her up.

What could be the cause please?
Click to expand...

Would low compression be a possible cause - advice please :)
 
Mine did this and it was low compression. I could easily turn the engine over by hand using the alternator belt, eventually I replaced the head and rebuilt it. No more stalling.
 
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