Bang on the solenoid with the handle of a screwdriver while actuating to see if it jolts to life. If it does then you'll know the solenoid is bad. Simply clicking doesn't actually mean it's closing the circuit like it's supposed to. You can also test it with a multimeter if you have access to one.
Have you checked all the fuses on the engine fuse panels? I can’t remember if there’s 1 or 2- used to have this engine and it was great.
As above, I’d also wallop(gently) the starter in case it’s a sticky solenoid and check the voltage at the engine in case of corrosion between battery and engine.
Is the new battery fully charged?
Check voltage at starter itself and the solenoid (With key engaged to start position). If good, whack the starter with a board or a hammer gently while someone turns the key to the start position. If it cranks over take the starter apart and see if there is anything obvious. Decide whether to replace it or not.
Whacking electrical components with hammers & screwdrivers isnt the best option imho. a few simple tests would be take a jumper lead from the positive battery terminal direct to the large live stud on the starter & try to start again, that will rule out the live cable. If that doesnt work try the jumper lead direct to the small terminal & see if the solenoid fires in if not touch the jump lead to 2nd large nut terminal on the starter solenoid & see if the starter itself spins up without engaging. If the solenoid fires in by touching the small terminal the problem is with the feed from ignition , if the starter spins with the lead to the 2nd large terminal the fault is with the solenoid. This is assuming its a pre engaged starter which i think that engine has.
I agree with Ken. A bit of electrical diagnosis with a voltmeter is the way forward.
Bit rusty on these motors, but I seem to recall that they have a solenoid or relay that then fired the solenoid on the starter itself. That’d be my first bet, that it’s engaged but not making a circuit. If that’s fine, then I’d check the solenoid on the starter itself.
Proper ends on the cables or the tatty things that have 2 screws clamping the cable into the battery terminal clamp?
This sort of thing: http://www.tradecounterdirect.com/se...pack-of-5.html
If it is that type than well known for corrosion on the cable end which will severely limit the amperage available.
Issue was corroded master battery switch and loose connections due to corrosion. This explains why solenoid was working and starter wasn't plus the intermittent nature of the issue. See photos.
Took flipping ages to remove the switch unit as was in awkward position.
Rewired without isolator switch and down from twin to single battery as interim measure.
Also added quick release battery terminals to serve as isolation in interim.
Locating batteries and isolator in transom on a rib is a dumb idea. Going to relocate batteries / install new battery isolator to cockpit area.
