Starter Motor

[ged in oz]

So, on we go and the next weakest link in the chain appears to be presenting itself. The Starter Motor...

It’s been steadily deteriorating over the past couple of weeks and is now becoming obviously unreliable as in, it’s about to drop its bundle! It baulked at each attempt to start today, with the telltale clunk!, clunk!, but eventually it has managed to get enough rotations to fire it up after 4 or 5 button presses.

I’m not sure that this issue isn’t related to the “spontaneous starter engagement” issue that I had a few months ago where the Starter would just randomly engage at 60 klm/h!, which can’t have been good for it.... That issue was solved by replacing the (original 1983) starter relay, the neutral switch and the clutch lever switch, which were each stuffed.

I recently had the timing cover off and so I checked the earth connections and tightened starter connections as part of that process, so I doubt that the issue is there. I haven’t put a multimeter on it, but there is plenty of voltage to spin it once it actually engages, so again I don’t think the problem is battery related either.

I’m pretty sure that a starter rebuild is in order, but any guidance or advice is again much appreciated.

[Bob_Roller]

There is a thread in the R65 Technical FAQ section .
The starter shown is for a Guzzi, but the same Bosch starter  as the airheads bkes use .

[ged in oz]

Thanks Bob. I did do a quick search but I missed that.....

Hmm, that’s gonna keep me busy for a couple of days.

[Tony Smith]

They are a dead simple, basic automotive type starter.

Pull it out, clean all the accumulated crud out of it and then reassemble puting high temp grease in the right places. is generally all they need.

Thing to watch:

Bendix unit can give trouble, given yours engaged a few times while the engine was running I'd look carefully.

Armature Bushes, usually these are just dry and HT grease fixes that. If you find them worn your local auto electrician can supply new ones.

Brushes - These wear very, very slowly, but if you need new ones, your local auto electrician will have them.

Armature contacts - theoretically these can wear, but I've never seen a set worn beyond usability, what can happen is small bits of conductive crud can get in the gaps = clean and polish using 3600 grit paper and carefully blow clean.

Pull-in solenoid - cheap and readily available at your auto electrician These work fairly hard so I'd swap this out if I had any suspicion it was not working perfectly.

Field coils - I would not remove these from the housing, the mounting screws are a bear to get out -a connectivity test will quickly tell you if there is a problem, otherwise just clean and inspect for mechanical damage. If there is a problem new ones are available relatively cheaply from Bosch.

Resist the temptation to replace with a cheap(ish) Valeo starter - they are unmitigated crap!. The much vaunted Nippondenso replacement is not quite as straight forward
to fit as you might hope and is hideously expensive.

[mrclubike]

OK before you tare into everything
(it still isn't a bad idea to tare the starter apart and clean and lube it but do this first)

Make sure the trans is in neutral !!!!!!!!!!!
LEAVE THE IGNITION TURNED OFF
Get a jumper wire
Connect one end to battery positive
Momentarily touch  the other end to the terminal on the stater that has a Black wire on it (this is the signal from the starter relay)
See how it cranks
If it cranks well every time you touch it
It means you still have a voltage drop to that terminal and your starer is more than likely fine and you have a wiring problem
Yes I know you have replaced the relay but try this  anyway

If it acts the same as when you try to start it  from the button then you definitely have a starter issue
Then take it apart   

[ged in oz]

Thanks heaps guys. A plethora of useful tips right there! I was thinking there must be a simple test to eliminate the actual circuit from the starter function as MrC has outlined, so that will be well worth the time.

I’m up to my ears in work for a few more days yet, but the Mrs is off galavanting for a week or so and I’ve got a MotoBins parcel already winging its way to me, with front wheel bearings which need doing and other little odds and sods, so I can see another little carport working bee coming up and ironing out a few more issues that the ravages of time and hard use have delivered the poor old bugga.

I’ll update this as I get into it. Thanks guys.