Feckin Starter Motor

[sladey]

It’s already in the car unfortunately

I might re-try the 9 tooth on the basis that it used to work and the 10 tooth is an unknown quantity for my engine

[fetuhoe]

9 or 10 teeth really won't matter much.

The 'fit' of the teeth between the flywheel and starter pinions is quite poor and will easily accomodate the difference providing the diametral pitch is correct.

The 9 tooth starters we use with a G50 are 1.7kW and have 9 teeth.

The 10 tooth seems to be 1kW so the reduction gearing may be different to provide enough torque.

[gridgway]

Does the new starter have the same throw as the old one measured from the mating face?

[sladey]

Thanks for that Chris - I was wondering that myself

GHraham I’m on it tonight so I’ll take it out and measure the two of them properly

[Nige]

Mark, I have a spare standard G50 starter you are more than welcome to borrow as a baseline check/get you going?

[sladey]

Thanks Nige - I may come back to you on that - will see how it goes tonight. I've got Ian coming round later once I've done the partial drop

[sladey]

Ok so another long evening - not without it’s successes and failures.....

Got the partial drop done (Jacked up, wheel off, ARB disconnected, shifter disconnected, gearbox dropped onto lump of wood) - I’m getting quicker at that now

Took the new starter motor out and tested it on the bench. Worked perfectly every time.

Decided to re-fit it, but with adjusting it along the mounting holes. If you remember this one has slotted holes meaning you have some movement when fitting it. When I originally fitted it, it was push in towards the gearbox as far as it would go (that’s the way the weight was taking it, so I went with it).

This time I moved it about half way along it’s adjustment. Tried starting it - still just got the whine. I’d charged the battery up prior to this so couldn’t understand it.

Following some made-up logic (the best kind!) I thought the engine might have some sort of lock in it - I’d emptied the on-engine oil cooler. So I put a spanner onto the crank bolt and trued to turn the engin

It was a bit stiff at first but then it turned OK.

Tried ignition again and it turned over and started!

Very happy - I put everything back together again. Ian arrived then. We discussed the tests I’d done on the starter motor.

I went to start it again - just a whirr again. I turned the engine over with a spanner, and it turned. After a few goes though it went back to whirring.

Ian checked the voltage across the battery. - too low - so he went home and got his booster

With the booster on I got the same symptoms - whirring unless I turned it over a bit first. Eventually I got it properly starter and drove it round the block (felt great!). Came back in and turned it off. Started again fine.

WE chatted about it for a while and I tried again - whirring.

On reflection and mainly by elimination we reckon I need to adjust the placement of the starter motor again - moving it away from the ring gear.

The starter motor works properly; there’s no problem with voltage when the power pack is connected. WE thought the whirring was it maybe hitting the edge of the ring gear instead of engaging with it. My turning the engine over meant it connected in a slightly different place.

So the plan is on Thursday night to do the same again - partial engine drop, adjust the starter position, and try it again. Fingers crossed!





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[sladey]

In other news I haven’t run it properly yet and I’ve already got an oil leak - looks like it’s from the engine mounted oil cooler



I can apparently replace it while it’s in the car.....


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[gridgway]

So here's my theory. It's not throwing out enough, so the teeth are not fully engaged before the starter spins up. It's a bit marginal so sometimes it engages and other times not. It's certainly possible that your lateral adjustment might be necessary. But my guess is that it's the throw.

Perhaps someone can measure a standard starter from mating face to both ends of the sprocket fully extended.

It's very much the same symptoms I had on my single seater. Although there I had a clear view of what was happening which was very helpful!

Graham

[gridgway]

Another thought. Do you have enough clearance and access to measure the distance from the mounting face on the bellhousing to the ring gear?
Graham

[964RS]

I think Ian is to blame. He's a jinx.

Every time he comes to mine we manage to get the 65 started and then next day just whirring.

He's the Whirrmeister

Still waiting for Fenn Lane to tell me when they can swap my bloody mechanical pump to electrical....to be fair it's only 7 months

[sladey]

When I tested it on the bench it was throwing out perfectly every time. I measured how far it needed to go out and it was 36 - 41mm (by eye with some engineers calipers) - the new starter motor cover that really well.

If adjustment doesn’t sort it I’ll probably be back to a stock one. Fingers crossed though - having talked it through it would make sense.

[mean_in_green]

Been through the same with high torque starters (three different units in fact).

Lost interest, fitted a Bosch one and it's started every time since.

Did the seals on my oil cooler without dropping the engine - not that bad to do.

[Magnum]

So.....

I know this still seems to be "in the air" and apologies to OP if this is a thread diversion.......but I had been thinking of getting a lightweight starter motor for my 915 box/3.2 hot rod.

Of course the consequences of shipping the damn thing half way round the world and then finding it doesn't work or is crap quality are horrible - it becomes simply throwaway as getting service from a UK based vendor and shipping backwards and forwards isn't going to happen.

So with all this negative feedback from various folk - I have to ask is there one supplier/brand that consistently works?

Help!

[Lightweight_911]

My personal experience Magnus:

I have fitted lightweight high torque starters to several early 911's & my 904 in the past (911, 915 & 914 transmissions) & have never had any problems.

In each case the starter was purchased from AES (Auto Electric Supplies).