Starter Motor Blues

[jonathanhsm]

Anyone know how to remove the starter motor from a Perkins Perama M20 – which is pretty much identical to a Volvo MD2020 ?

I can see a 6mm hex bolt on the rear … and at least one standard bolt coming from the front.

I want to take it off and test it because I may need to replace it. At the moment there is a faint clunk when turning the ignition which comes from the relay which starter shares with glo-plugs.

Batteries are fine and I’ve buffed up all the connections so assuming the starter or solenoid has gone bad.

Any advice much appreciated !

 

[KevinV]

Try jumping the starter direct before going to the effort of removing it? Might just save you some skinned knuckles if it works.

 

[jonathanhsm]

Er what's the best way of doing that ? Screwdriver between the terminals? And if it works does that mean it's the solenoid ?

 

[LadyInBed]

Del - already said

 

[William_H]

I am not sure what kind of solenoid system your starter has. One system uses a solenoid (relay) simply to connect battery to starter. It may be mounted on the starter body or remote from starter. This uses the inertia of the pinion gear to slide up a spiral spline to move the pinion gear into the ring gear so getting drive from starter motor to engine.
A perhaps more sophisticated system uses a solenoid to not only make electrical contacts but also physically push the pinion gear into the ring gear before applying power.
So on the first type if you short the terminals with a screw driver you will get a normal start action. (beware of igniting hydrogen from battery charging from the sparks)
if however on the second system if you can get at the terminals of the electrical contactor and short them you will get starter spin but no engagement to engine. This might help you resolve the failure. My guess however is that you are right the starter with solenoid needs to be removed for cleaning and test. Just how you get at bolts, well you have my sympathy. ol'will

 

[VicS]

Anyone know how to remove the starter motor from a Perkins Perama M20 – which is pretty much identical to a Volvo MD2020 ?

I can see a 6mm hex bolt on the rear … and at least one standard bolt coming from the front.

I want to take it off and test it because I may need to replace it. At the moment there is a faint clunk when turning the ignition which comes from the relay which starter shares with glo-plugs.

Batteries are fine and I’ve buffed up all the connections so assuming the starter or solenoid has gone bad.

Any advice much appreciated !

I don't understand what you mean by "the relay which it shares with the glow plugs"
According to the wiring diagram I have found (See below) the relay is the glow plug control relay. The starter solenoid is energised directly from the key switch when turned to the start position.
( the VP MD2020 has two relays. One is the glow plug relay the other is the starter control relay)

Several things you can check or try to diagnose the problem before removing the starter motor.

Firstly check to see if you have power at the small terminal on the solenoid when the key is turned to the start position. If yes then probably a starter or solenoid fault ... brushes perhaps if not then a wiring fault ... open circuit between the key switch and the starter or a faulty key switch.

Try connecting 12 volts directly to the small terminal on the solenoid by shorting it to the main battery + terminal on the solenoid . >This by-passes the key switch and the wiring .

Try shorting across the two large terminals on the solenoid .> If the starter motor does not spin then it is almost certainly defective.

Take care when doing the above. .> the engine may unexpectedly crank and possibly start.

 

[Refueler]

I'm surprised no-one has suggested the old 'Farmers trick' ........

Before doing anything else - Give the starter shaft end a few good whacks .....

I know my Perkins (4-107) starter when left too long is reluctant to 'throw the gear' into mesh ... a few whacks and it soon complies !!

If OP is hearing a 'CLUNK' when pressing start ... mmmmm relay is usually more loud hard CLACK ... CLUNK gives me impression that starter is trying to throw but not meshing.

 

[roaringgirl]

I started getting a reluctant starter clicking without throwing all the way. After shorting the terminals to prove it still works properly, I wired a relay into the circuit so that the power for the solenoid comes more directly from the battery. Our 20yr old Yanmar still starts first time every time.

 

[VicS]

I'm surprised no-one has suggested the old 'Farmers trick' ........

Before doing anything else - Give the starter shaft end a few good whacks .....

I know my Perkins (4-107) starter when left too long is reluctant to 'throw the gear' into mesh ... a few whacks and it soon complies !!

If OP is hearing a 'CLUNK' when pressing start ... mmmmm relay is usually more loud hard CLACK ... CLUNK gives me impression that starter is trying to throw but not meshing.

Even a pre engage starter can jam. We'll worth turning the engine a little with a socket wrench on the front crankshaft nut. If it's jammed that should free it with an audible click/clunk sound.
To cure any tendency to jam the motor will have to come off for attention and lubrication of the pre-engage mechanism. (See below)

Nobody has answered the original question of how to remove the starter motor.
AFAIK, after disconnecting the wiring, just a case of removing the two bolts holding the motor by its mounting flange to the flywheel housing.

 

[jonathanhsm]

Many thanks all ... I'll try your remedies when it's stopped raining sideways and blowing a hooley
Meanwhile as I was upside down with a spanner I thought I'd improve access by doing some things i'd been intending to do over the winter ... removing high rise exhaust elbow for inspection/decoking , and removing the alternator which needs a good clean ... the back of is blackened with powder presumably from worn brushes which probably need replacingl
Needless to say it's all filthy dirty so de-greasing and de-rusting on the list
Can of worms...but at least I'm not missing out on any sailing !

 

[Refueler]

I was always advised and when I had my starter repaired couple years back in local Harbour workshops ..... not to grease or apply lubricant to the shaft ..... to avoid having salt and other crud accumulate. Light oil or spray - occasionally.

 

[VicS]

I was always advised and when I had my starter repaired couple years back in local Harbour workshops ..... not to grease or apply lubricant to the shaft ..... to avoid having salt and other crud accumulate. Light oil or spray - occasionally.

You did not lubricate the old inertia /bendix gear types in cars because it would attract dust from the wearing clutch disc.
You should not get salt or any other debris in the flywheel housing on a boat.

 

[Refueler]

You did not lubricate the old inertia /bendix gear types in cars because it would attract dust from the wearing clutch disc.
You should not get salt or any other debris in the flywheel housing on a boat.

Its too cramped to photo my engine and starter .... but I have to disagree about possibility of salt etc. .....

Sea air is laden with the stuff let alone any other possibilities .... my 4-107 is a not a sealed housing .... the starter sits in via a hole and other side where bendix protrudes is larger hole than the Bendix + shaft ...

 

[jonathanhsm]

Er I think I found the problem. I shorted solenoid to battery and the engine cranked, so I tested the ignition wire and found a severely corroded junction...see attached.
So I won't be taking the starter motor out just yet ! Many thanks all

 

[LadyInBed]

removing the alternator which needs a good clean ... the back of is blackened with powder presumably from worn brushes which probably need replacingl

More likely to be dust from a worn drive belt, but checking and cleaning the around the brushes is well worth while for peace of mind.

 

[Refueler]

Er I think I found the problem. I shorted solenoid to battery and the engine cranked, so I tested the ignition wire and found a severely corroded junction...see attached.
So I won't be taking the starter motor out just yet ! Many thanks all

Well done .....

It is a boat and its a terrible corrosive environment ......

 

[peteK]

Er I think I found the problem. I shorted solenoid to battery and the engine cranked, so I tested the ignition wire and found a severely corroded junction...see attached.
So I won't be taking the starter motor out just yet ! Many thanks all

I have the same engine with the same connections but I have mine taped over.

 

[jonathanhsm]

I have found another connection further down the line as well. I can see why you taped yours over ... there seems to be a gap between the two halves inviting salt air to do it's worst.

I am thinking of a cheap simple ten way well vaselined terminal block enclosed in an IP65 junction box with waterproof glands for the loom to enter and exit... unless anyone has any better ideas ?

 

[Refueler]

I'm a believer in cleaning up contacts with emery cloth ... good spray with Contact Cleaner to remove any dust / crud ... bolt back up and then smear vaseline over before any damp or corrosive air gets to work again ... that way - always easy to clean up / check later ...

It worked on cars years ago ...