Yanmar Starter problem - question 2

[BobnLesley]

Thanks to everyone who responded to my query about switches/wiring/relays with regard to our 3GM30F, sadly I've found (I think) another problem: I took off and cleaned up the starter motor this morning, as suspected the brushes are getting short, but of more concern was opening the unit (A Hitachi S113 - 303) and finding only three carbon brushes? Is that right, or should there be 4? The carrier-plate certainly has a couple of locating holes for a fourth brush unit, but it's not there, nor are there any signs that it ever was.

 

[earlybird]

My Yanmar manual quotes S114-303 for the 3GM30.
Described as a 4 brush, 4 pole motor.
3 brushes is most certainly not right!
I think you've found the cause of your earlier problem.

 

[BobnLesley]

I think you've found the cause of your earlier problem.

My thoughts too, though the more I look at it, the more certain I am that the fourth pole/brush has been missing since new; the opposite brush to this missing pole is the one that's worn far and away more then the 'balanced' pair at 90 degrees to this gap.

Anyone any supplier suggestions for a new carrier plate & brush holder?

 

[pampas]

Not unusual to have 3 brushes fitted, many older type starters used this system, modern types normally have 4.

 

[BobnLesley]

Not unusual to have 3 brushes fitted, many older type starters used this system, modern types normally have 4.

You're right, though I've never seen the arrangement before. Someone kindly provided me with the hitachi part number and when I googled that I found that it only has thee 3 brushes; so, I just need to get three suitably sized brushes. Actually I may get the whole thing, it's only about £3 more than buying just brushes and my cack-handed soldering technique is better able to cope with connecting the holder plate than individual brushes.

 

[pampas]

Tip. if the coils are copper OK if aluminium cut tail short do not remove the bit left welded to the coil end, clean the remaining copper braid, slip some heat shrink over the new tail and solder to the copper if quick, slip heat shrink over the still hot coil end and allow to cool.