I think I may need to have the starter motor overhauled. Starting is reluctant, even with new fully-charged batteries and new battery cables. Has anyone any tips on the best way to remove it (AEC engine)?

My bus number (if any): RM577

Glad you've got some new cables. You need to check your Battery Isolation Switch. My poorly performing starter motor turned out to be a faulty BIS. Repairing the switch solved the problem.

http://www.rmoof.co.uk/Battery%20Isolating%20Switch.htm

Also check all the connections between the battery and the starter motor. Undo them and clean up the mating surfaces. I filed mine back to gleaming metal.

Getting the motor off is fairly straightforward if you clamber underneath you will se how it is attached to the engine. I've changed motors by clambering underneath. They are very heavy and you will need an assistant to take the weight. Undo the cable connections to start with and note down the polarity but make sure you isolate the battery first.

My bus number (if any): RM238, RM471 and RM2213

Thanks for the suggestions Chris. My "new" cables are actually loans from RM13!! So I still need your contact in Peterborough to make me up some new cables when he returns from holiday (16th I think you said?)

My bus number (if any): RM577

Incidentally I have not yet got an isolator switch (so that cannot be the cause of the problem!) but would like to fit one. If I fit one behind the bench seat, would that affect what type of cable terminator I order?

My bus number (if any): RM577

Hi......I am not overly qualified to lecture on electrics but on 765 we had sluggish starting for years.Constant charging of batteries, worry at the rallies whether she'd start at the end of the day,and three changes of starter motor. Cables cleaned and re-terminated and swapped for secondhand spares. Batteries and rectifier renewed. Until the magic day whence we found the alternator was not charging. A change of alternator, a substitute control box,(also faulty!...the alternator requires a low voltage input from the control box or it will not produce current) and 27.6 volts finally arrives at the battery end! From that moment on......starting to dream of! I have since wondered if from the initial moment of the engine turning over, does the alternator give the starter a shot of juice? Regards Ian.

My bus number (if any): RM446 and RM765

A lot of starter/battery drain problems are down to the cables.
insulation failures often hard to detect, poor end connections and water ingress all cause poorer conductivity and resistance levels.
So check or replace the full cable runs and use the best quality replacement cables and terminals. It makes a huge difference with reliability.
Try also using a commercial vehicle battery connection spray. It's a greenish type fluid that creeps and seals out moisture from ingessing into the connections and cables.

Ian is quite right John, if the alternator and control panel are is not working well the whole charging system goes wrong. As Ian says the control panel needs a charge to get the alternator charging back to the battery. You should be able to do a check on this bus relatively easy, with the refurb RMLs there are all sorts of extras added in for various functions that can cause problems with starting and charging.

My bus number (if any): RTL 960 RMC 1458 RM 1585 and several RTs