nb Innisfree

Innisfree's alternator (24v 10a) would give full output at approx 1400 engine rpm when cold but once it got hot it would need about 1800rpm, a good case for extra cooling.

If the cap fits etc...

Don't forget you can't have a shallower draft without less interior headroom, modern canal boats are usually approx 7' from exterıor surface of bottom plate to top of roof to ensure bridge and canal bed clearance, (when going under bridge) I doubt there is enough space for conventional concrete ballast.

Some sort of fan cooling, bringing cool outside air, would take a bit of inventiveness to achieve.

It could be the alternator playing up as it reaches a certain temp, changing the it for a new one, or one that works OK would be my next step, expensive maybe but it will eliminate a poss prob, if it doesn't work you have a spare. Also I would look at introducing some extra cooling for the alternator.

Last gale blew a roof tile off, replaced it couple of weeks ago and roofer noticed a few of our ridge tiles were loose, he bedded them back on last week, looking at the wind today we've prob had a close shave! + I've moved the car away from the house.

I would give a few turns on the starter with stop out until oil pressure gauge registers. won't do any harm and will circulate oil.

In the old days of petrok/diesel cars I used to notice in cold weather that it took about an hour for the heater to reach max output and the engine sort of 'peaked', I assumed it was because the engine & g'box had reached its max temp indicated by oil temp if a gauge was available, same with the boat, very gentle at first and gradually increase load to ensure it warms up quickly. With Innisfree I had the facility to preheat the engine which in very cold weathers could still take 15 mins or so at normal canal cruising speed to reach that point, without preheating it could take well over 2 hrs, so my advice would be to load the engine as soon as it is warm.