Mercruiser Engine Stalls After Replacing Calorifier

[magicaltrout]

Hello folks,

Random question, wonder if anyone has any tips.

I had the boat engine serviced last week so I know its all good-ish. This week I replaced the old water heater with a small 10 litre calorifier. Having removed the old hot water lines from the engine I found they were completely blocked, so I unblocked them before attaching them to the new unit. Now the engine starts but stalls in idle, but thats the only change I have made. Anyone got any ideas as to why this might be happening or is it likely unrelated?

 

Tom

[Smoggy]

Does it have an auto-choke operated by the cooling system? Could be an air lock making it think the engine is stone cold and over fuelling.

I'm assuming petrol engine here.

[OldBerkshireBoy]

When helping on plumbing forums I always suggest that any valve that was closed is checked to now be open, gate valves with wheel handles can be misleading.

[magicaltrout]

I tweaked the idle screw and its okay now. I assume the extra water being pumped around the engine altered the rev point?