Mk 3 starter relay jamming on

I've been whacking the relay with a spanner and that splits the contacts. I'm using a Mini relay though so I have no idea how there could be too much current draw for it from a Commano starter motor. The Starter Motor is a 4 brush conversion. I run a Wesco 19 Amp Hour AGM battery and a Sparx 220 Watt alternator set up.

The SM has always sounded laboured however, so perhaps it just dowsn't spin freely enough. I might have to add ball bearings and use a Harley Prestolite 4 field coil cage.

Previously wrote:

Hi,

This may be stating the obvious but if it is the solenoid latching on then this is seriously dangerous. Switching the ignition off will not prevent the starter motor from still trying to turn. If the starter cannot turn the engine over then it will carry onstraininguntil either the battery goes flat or something catches fire.

If turning the ignition off does stop it then it is in the handlebar switch and not the solenoid.

Ifturningthe ignition off does not stop it then change the solenoid before pressing that button again.

If you have a standard starter and battery then it will always sound laboured unless you are really low on compression.

Regards

Tony

Battery, starter and whole electrical system fully upgraded. Solenoid is from a Mini.

Previously wrote:

Previously wrote:

What do you have to do to un-jam it?

I would think that the only thing that could happen would be that the contacts are fusing together because of a too large amp draw.

The ES solenoid/relay on my Mk 3 has started jamming on occasionally when starting the bike. Its quite a frightening problem - has anyone else got any experience of this?

cheers

Luke Albanese

Mine jammed once, never did find out why. I have a 4-brush conversion and bigger 19Ah battery, etc. What I have found is that if one of the brushes hangs up then the current draw is massively greater and the motor struggles to turn over the engine. So, your description of it sounding laboured might point to a brush making poor contact?

Norm Lorton

Now this sounds like a lead Norm, I'm going to look into this at the weekend. Many thanks!

Previously wrote:

Luke - does it reset immediately when you switch off the ignition? Is it affected by temperature? It sounds like it might just be old and knackered and need replacing! I know how it feels...However it may be worth buzzing the switch out just in case you have sticking contacts at that end as well.Also worth checking the wiring, as a matter of course anyway.

No - the problem remains when ignition is off - the relay is jamming - the contacts welding themselves shut. There is simply too much current draw I suspect, but why?

Norm Lorton has an idea (see below) which I will investigate.

L

Interesting - and thanks for all the help.

The brushes are OK, but the armature is really quite 'stiff' in its oilite bearings, I suspect they need replacement (or at least lubrication) so I will do this.

Does anyone know how to get the bearings out of the end caps (esp. the blind one on the brush end?)

I may carry out the ball bearing conversion on the drive end cap.

There is the whole issue of the fact there are only 2 field coils as well (why did Norton do this?) so despite using 4 brushes the torque is quite low still. I have ordered some regular torque Accel field coils 40013 ($9.99 on e-bay !!) and will have a local Starter Motor shop fit them to the casing and get them to do the brushes and the bearings at the same time.

I'll let you know how it goes!!

Luke Albanese