(Another) starter motor problem thread

[ndevans]

The starter on my car is playing up. Long story, so make yourself comfortable....

The car had been in the garage to 2 weeks, was starting fine beforehand. When I came to start it, it would only turn over slowly, too slow to start. It's a 1275 ex Marina block with HC pistons and big valve head, it's not possible to hand start it (well I've never succeeded anyway, but maybe I'm not big & strong enough).
I thought it was simply a less than fully charged battery, but no. The battery has been fully charged, which made no difference, and when I took it back to the shop for a refund, was tested and found to be delivering 460A. So I'm ruling the battery out (for now).

The starter was stripped and I found that the plastic brush cage had partly melted, due to getting hot after my repeated attempts at starting. This meant the brushes were not sliding freely. I cleaned it all up so that the brushes were able to slide freely, and reassembled. Same as before, slow turnover, not fast enough to start the engine.

I tried a good second hand starter from a member of the local branch, same result-slow turnover. Since then I have tried:-

• A spare solenoid

• A spare battery to solenoid cable (the one fitted was only a year old though)

• Checked the earth strap for tightness and integrity, then actually moved it to earth the block directly rather than the gearbox

• Used a jump lead to earth the starter body to the battery -ve terminal

All to no avail. The only things I have not tried swapping are the solenoid to starter lead, and the battery itself. I have tried jump starting from the modern car, but that does not help either.

Here's a short video of what is happening:-

https://photos.app.goo.gl/AdwwM51Q5LmorfED7

Any ideas please?

[philthehill]

Have you checked the serviceability of the earth return from the starter to battery.
There should be a woven earth return wire between the gearbox and gearbox cross member/chassis mount. This return wire may be placed elsewhere but it is important that it is in place.
To check serviceability - connect one end of a jump lead to the starter body and the other end to the earth connection on the battery. Try starting the engine. If the rotation speed of the starter increases then that indicates a poor earth return.
If it does not then you will have to look elsewhere for a problem.
The standard Minor starter is well capable of turning over a tuned high compression 1275cc engine.

[geoberni]

How fast does the Starter spin when off the car?
It does sound like a heavy load, but lets rule out a sluggish starter.
As phil says, clamp a jumper lead from the starter to the battery earth ...

[ndevans]

Have you checked the serviceability of the earth return from the starter to battery.
There should be a woven earth return wire between the gearbox and gearbox cross member/chassis mount. This return wire may be placed elsewhere but it is important that it is in place.
To check serviceability - connect one end of a jump lead to the starter body and the other end to the earth connection on the battery. Try starting the engine. If the rotation speed of the starter increases then that indicates a poor earth return.
If it does not then you will have to look elsewhere for a problem.
The standard Minor starter is well capable of turning over a tuned high compression 1275cc engine.

Hello Phil, thanks for replying.
Yes I have tried a jump lead between starter body & battery -ve, as detailed above.
The earth strap is in place, although was a bit mucky. I cleaned it, tightened it, no change. I then moved it to earth directly from engine block to chassis, having cleaned the block & chassis first. It made no difference.

[ndevans]

How fast does the Starter spin when off the car?
It does sound like a heavy load, but lets rule out a sluggish starter.
As phil says, clamp a jumper lead from the starter to the battery earth ...

The good 2nd hand starter was tried off the car when I picked it up, it spins freely.

For information, I am using the standard Minor flywheel & starter ring, & have been for 7 years. The engine is somewhat stiff to turn over, but as I say, it is fitted with HC pistons & a big valve head. It spins freely with the plugs out, both by hand and using the starter.

[ndevans]

Problem solved, thanks to @Kevin_C of this parish.

After about 5 weeks, I'd tried just about everything. 3 starters, 2 batteries, 2 solenoids, umpteen combinations of starter to battery cables and earth straps, and still it steadfastly refused to start. I'd tried all the obvious things, even giving it a good stern talking to and threatening it with being turned into hairpins and razor blades didn't work. I was stumped.

Two 'eads being better than one, Kevin kindly agreed to come over on his way back from the Sunday morning Bristol Branch breakfast meet at Fowlers Motorcycles in Bristol. After trying another spare starter (the fourth!), to no avail, I suggested we try the starting handle, to see how stiff the engine felt. On turning the handle, Kevin could hear the fan belt squealing. Turns out the water pump is seized solid! The extra load was too much for the starter (all 4 of them!) to spin the engine sufficiently fast to start. Off came the fan belt and it burst into life.

I'd tried the starting handle myself, but hadn't really noticed the fan belt squealing because I was too busy trying to turn the handle! Using the starter motor either caused enough noise to obscure the squealing, or meant that it spun fast enough not to squeal. I'd just fitted an electric fan, and removed the fan blades, making it more difficult to notice the fact that the pulley wasn't turning.

So thanks to Kevin for giving up his Sunday morning!

[rocco]

Great to hear that it worked out in the end, and all for the price of a new water pump.

Do I understand correctly that you were able to turn the engine over with no problem but that the seized water pump prevented 2 batteries from doing so? Did the pump look anything like mine?

20230916_120058.jpg (341.83 KiB) Viewed 3151 times

[ndevans]

Great to hear that it worked out in the end, and all for the price of a new water pump.

Do I understand correctly that you were able to turn the engine over with no problem but that the seized water pump prevented 2 batteries from doing so? Did the pump look anything like mine?

20230916_120058.jpg

I could turn the engine over on both starter motor & starting handle, but the starter motor would not turn it fast enough to actually start. I tried 3 starters and two batteries*. It was too stiff to start it with the handle, but since I've never been able to start it on the handle, that didn't worry me too much.
I haven't got the pump out yet, so I don't know what condition it is in. It's only two years old, and I use corrosion inhibitor in the coolant, so I hope it does not turn out like yours! Could be a bearing failure.

Cheers N

*the battery from the modern, a 1500 diesel, would not start the Morris, but the Morris battery started the diesel first time.