Starter motor solenoid.

Bendy toy · Jun 22, 2018

Does anyone know if the (pre engage) solenoid can be changed out or is it basically a scrap starter?

My old starter burnt out last year. Replaced with a service exchange unit from Motorworks. Happy days.

A year later, I’m having problems. The starter won’t engage properly as soon as it tries to turn the engine it flips out and the motor just spins. Eventually it will hold in and bike starts normally.

The ring gear and starter pinion are fine. I’ve connected jump leads to power & earth even direct to the motor. No change.

Stripped the solenoid. No nasty smells and resistance to earth is ok. Also oiled the plunger/piston.

Made sure the trigger wire connector is not loose. No change.

It will be ok for a while then back to it’s old ways.

Bendy toy · Jun 22, 2018

RT motors are a fraction of the costs for a GS motor. Does anyone know if the RT motor will work on the GS?

Bendy toy · Jun 24, 2018

Any help? Anyone?

I really don't want buy another starter after barely a year.

Santa-2512 · Jun 24, 2018

When i was looking into mine, figurativly speaking,

If i recall,

all parts are avialable as spares - Apart from the solenoid

i think its to do with its internals

I'll see if i can find the company i dealt with for spares

SteveM · Jun 24, 2018

Maybe give THESE guys a call Bendy. I’ve always found them to be pretty good to deal with.

Bendy toy · Jun 25, 2018

Hi Steve - The link doesn't work could you try again. Thanks.

It's an odd one as sometimes it holds in fine but usually it pops out before the motor can turn the engine. Whip the motor out and it will work just fine for a few days, then it's acting up again.

The solenoid coil and iron core just bolts onto the motor casing.

AlexG · Jun 25, 2018

SteveM's link is probably http://www.asarotatingelectrical.co.uk.

SteveM · Jun 25, 2018

AlexG said:
SteveM's link is probably http://www.asarotatingelectrical.co.uk.

It was. Thanks Alex

Pukmeister · Jun 25, 2018

Can't help much without seeing it in bits. Is it the type with a set of retaining circuit contacts across the solenoid ?

Bendy toy · Jun 27, 2018

Pukmeister said:
Can't help much without seeing it in bits. Is it the type with a set of retaining circuit contacts across the solenoid ?

Mine looks to be a sealed unit. The solenoid coil is bolted to the motor top with three M4 screws. The other end has the two heavy and one small electrical tag riveted in place. Inside, the iron core is free to slide. Mine is nicely lubed with no signs of it jamming in any way. The lever that engages the starter gear is free moving so no reason to suspect that's jamming.

Next job (when I find my bigger soldering iron) is a dab of solder on the trigger connector rivet but TBH it's a long shot.

Pukmeister · Jun 27, 2018

The solenoid should move under the action of the small electrical trigger tag being energised, which then engages the pinion. At this point, the solenoid armature should close the two heavy contacts to put power from the battery onto the motor windings and spin the pinion, thus cranking the engine. Once the engine exceeds starter speed it should throw out the pinion down its helix with such force from the much larger diameter flywheelthat it breaks the two heavy contacts and stops the motor.

If your starter is spinning the motor before the pinion is fully driving, I suspect you either have worn starter ring gear or a bent operating arm in the starter motor thats allowing early operation of the motor prior to full pinion engagement. Is the starter motor fitted to the correct depth on the engine block and is it an identical size to the old starter ??

It might be worth pulling the starter motor, selecting a high gear then turning the rear wheel to rotate the engine by hand whilst checking the ring gear on the clutch/flywheel.

Bendy toy · Jun 27, 2018

The starter begins to turn the engine then flips out before the engine has properly caught. There's no grinding of teeth - it just doesn't hold in place for long enough.

My initial thoughts were "Oh F ring gear failed". But when the motor was pulled out, the ring gear is fine. That led me to suspect the starter pre engagement mechanism but mechanically that also looks fine. The engine always stops in one of two places. In both areas, the ring gear teeth are slightly cleaner but all good.

One test I have not done is to put 12V from the battery to the starter trigger spade connector. If that works I'll know the issue is bike wiring. If not, I'm back to the starter solenoid being the issue.

Just to confirm. I've tried jump leads to prove the earth and direct to the starter. The weak pinion engagement is unchanged. It seems as if the starter is not being held in strongly enough. Any interest from the engine kicks it out.

Pukmeister · Jun 27, 2018

Maybe you have a volt drop on the pilot cable for some reason such as corrosion, loose connection, chafed wire, worn starter relay internal contacts ?

Why not clip and multimeter across the pilot wire / earth point and measure the voltage when the starter button is operated ??

My thoughts are that if the solenoid is only getting a weak pilot signal, it may be enough to briefly pull it in but not keep it there. It could also be a poor return earth path between the starter motor casing and the engine block e.g. alloy corroded, paint, bolt thread grease etc.

Norfolk Tiger · Jun 27, 2018

If the motor continues to spin the solenoid plunger must be engaged as it pushes a copper contact internally against the 2 main terminals joining the battery feed to the motor. Normally when you have the symptoms you describe it is the clutch in the pinion slipping. Easy to test off the bike clamp the starter in a vice use jump leads to provide power,when you energise the trigger wire the gear punches forward and the starter is spinning use a piece of wood to apply pressure to the turning gear. It should eat into the wood my suspicion is that your gear will slip.

Bendy toy · Jun 28, 2018

Norfolk Tiger said:
If the motor continues to spin the solenoid plunger must be engaged as it pushes a copper contact internally against the 2 main terminals joining the battery feed to the motor. Normally when you have the symptoms you describe it is the clutch in the pinion slipping. Easy to test off the bike clamp the starter in a vice use jump leads to provide power,when you energise the trigger wire the gear punches forward and the starter is spinning use a piece of wood to apply pressure to the turning gear. It should eat into the wood my suspicion is that your gear will slip.

That's interesting. The starter does continue to spin. I'll get a look at it over the weekend.

Is it's possible to get a new pinion clutch? I think we know the likely answer.

Pukmeister · Jun 28, 2018

Maybe worth giving motorworks or sherlocks a call ?

Santa-2512 · Jun 28, 2018

Are we talking about a valeo D6G2 unit

if so

Part numbers

Solenoid 594686

Pinion gear 594685

Armature 594650

Gearbox & shaft 594688

All parts are available -- trouble is not many places want to sell as individual components

When i was hunting parts for mine i had to go to suppliers in Poland direct

Santa-2512 · Jun 28, 2018

Given the cost of individual parts & vat & shipping etc

Might be cheaper to buy a new or refurb unit

Part number on real oem show as

BMW
12417712231 Valeo

Superscedes
BMW
12412306140 Bosch

This site says £105.20 inc vat - 20 day lead time ( id say this is a reman unit)

https://cars245.com/en/item/valeo-438177-starter/

Bendy toy · Jun 28, 2018

Pukmeister said:
Maybe worth giving motorworks or sherlocks a call ?

It is a service exchange unit from MotorWorks, fitted a year ago. Unfortunately, their warranty is only 3 months.

Looks like the Arrowhead would have been a better option and a few quid cheaper.

I'll call Motorworks and have a play over the weekend but may have to settle for a new starter motor.

Hoff · Jun 28, 2018

My Bosch starter on my 2012 TC gave up the ghost a couple of months ago and I fitted an Arrowhead from Motorworks, price about the £240.
Easy to fit but you do need to wriggle it around to get it in. The only difference was I could not fit the black plastic cover, item 6 on the OEM drawing, so just left it off.
Its only been a couple of months and 4000 miles but so far it has been excellent in starting the bike, lets hope it continues!!

Starter motor solenoid.

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