VicS

You really need something which will be a much larger load. I have an old car headlamp bulb ( with only one filament now working) on a...

Drill the ends of the axle and upgrade to split pins , or if you are likely to want to remove the wheels regularly to "R" clips.

In post #3 I suggested looking at the key switch , " the behavior when you play with the key would make me look at/ test the key switch...

It is on the stop solenoid and operates the solenoid manually when pressed

This type of thing? Grease cups.

Id not expect it to fail to respond to either of my suggestions unless in the first the starter motor is faulty or the main battery...

Two things you could try with caution ( the earth must be good of course, or nothing much will happen) 1. Try shorting together the two...

The Op's Beta will have a pre-engage type of starter , not the inertia type with a Bendix mechanism which you describe. Slightly...

The starter motor and solenoid are on the port side below the heat exchanger. ( see attached diagram) Your problem does sound like a...

Neutralise leaking acid with a solution of washing soda.

Not if the fire extinguisher is heat activated rather than smoke activated.

A modern digital meter takes so little current that it can give a normal voltage reading through bad connections ...... guaranteed to...

There is a 3amp fuse in the panel but it is only in the supply to the warning lights, buzzer and tachometer If it has blown or making...

Until the OP tells us what engine and, in particular, if it is direct or indirectly cooled it is impossible to give any meaningful...

What engine? ( Direct seawater cooled or indirect ?) Pump impeller changed recently ? Heat exchanger ( if relevant) cleaned recently?