I brought the starter motor from the D6 back to Sydney with me to have it looked at and I am wondering if anyone here can suggest who might be good to send it to?

When I test ran the motor off the dozer it ran fine and seemed strong. So I don't think that there is any problem with the windings.

Specific issues are:

1. I think that the relay is sticky and not disengaging sometimes - meaning that power stays applied to the starter motor even when the ignition switch is released (I confirmed that it's not the switch by removing the switch and just connecting the two ignition wires). I assume that replacing the relay shouldn't be a big deal and could be done with aftermarket parts even?

2. The bendix gear doesn't seem to move freely enough on its shaft to me. Often when I run the starter, but the pony motor doesn't start, the bendix will stay engaged to the flywheel. I'm thinking that this may be because the bendix isn't lubricated correctly. Can anyone tell me what the bendix should be lubricated with? I tried grease and that helped, but not enough. So I'm guessing that there is an optimal lubricant for that application.

Hi Langdon,
The bendix you are looking for is a 9b8901 or 7n6068 the Delco part No is 1868804 it is used on many tractors like John Deere, international, Ford, etc. So most good auto elect's should find it easy.

Regards

Hi Rax200, thank you for the bendix part number. Much appreciated - but! It's teeth are not worn, the shaft looks good, and there's no play in it, so I don't think it needs replacing, it's just a lubrication issue I think.  I'll talk to my mechanic about it, he may be able to recommend an autoelectrician to take a look at it for me.

i would dismantle the relay and give it a good wash out with some shellite or contact cleaner. a photocopier tech put me on to that he has repaired many switches etc on copier simply by soaking them in a jar of shellite. note let it dry really well it is flammable.
same with the starter itself it may well just be gummed up
reassemble with a little high temp white lithium grease. on the bearings and bushes yoke etc.
most autolec would have the gear to rebuild them anymore
todays gear is RNR rip er out and replace.

Hi Trainzkid88, ok that's good information.  When I get my truck back from the mechanic I'll pull the relay (solenoid?) off and see what I can do.  I haven't used shellite for anything since my school days and art class!  Have to pick some up.

Yes there's precious few businesses around any more who do that kind of repair service work (in Australia at least) - as you say it's mostly just disposable parts.

I've just been reading up on bendix servicing and it seems that "very light oil" (sparingly applied) after a good clean with kerosene.  So I'll do a minimal disassembly on the starter this week and give the pinion gear and threaded shaft a good clean and light re-oil.  If the shellite trick works on the relay then I'll be ready to go back and have another crack at it (and have saved a few dollars!).

One other thing I really need to do is work out the voltage of the starter motor.  I *assumed* that it was 12 volt, but having looked over the parts book I'm now thinking that it might actually be 6 volts.  I'm glad that I don't appear to have damaged it.

It wil not hurt a 6V starter to run it 12V. Just dont crank it for long periods.

Hi, LangdonStevenson.
All the electric starters for pony/pilot motors that I ever saw were 6 volt. I once hired a speed boat for water ski-ing that had a Holden EK 6-cylinder engine in - with a 6 volt starter AND coil - running on 12 volts - sure did start that engine pretty quick.

Isopropyl alcohol works pretty well too for cleaning parts like that. Again, let it dry completely before trying to reassemble but the alcohol evaporates quicker than shellite, kerosene, etc..

Just my 0.02.

Thank you Deas and Kracked1, that's good to know about the 6 volt issue.  I will be sure to not crank it too long!

Hi, LangdonStevenson.
Provided that the magneto is supplying good spark and everything else is in good order and tune, I suspect that you won't HAVE to crank it for very long due to the fact that the 12 volts is gonna really throw that engine over.

Rope starting the pony motor can be hit-or-miss simply because of the limited number of turns and the speed of rotation developed by pulling the rope. The 6-volt electric starting system overcame that to a large degree simply 'coz the motor was being spun faster and for longer periods. Add 12 'joltz' to the mix with a 6 'jolt' starter and the motor will be spun even faster.

Leaving the 6 'jolt' coil on that old Holden motor in the boat sure livened up the spark too.

On a slightly different note, let the boat idle forward to take the slack out of the ski rope and then reef the throttle open and I could be up and standing on two skis in about ten feet. It wuz QUICK. Mind you, the driver of the boat couldn't see a danged thing in front of him until the bow came down again. The 45 HP Merc. we had the week before was a definite 'also-ran'. BTW, this was 1966.

Just my 0.02.

Deas - yes I can imagine that the rope starter would be hard going!  Lawn mower engines are bad enough...

I think that the spark is strong, just have to sort out the fuel system next and hopefully I'll be off to the races.