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Mk3 Starter Motor Conversion Parts 4 Coil Case coils Brushes


I was thinking of fitting the 4 coils / brushes on my MK3.

 I just wanted some feedback from anyone who has fitted this



Highly recommended - our MK3 starter now turns the engine over like there are no plugs in it!  

A couple of things to take care of though…

  • You must upgrade the large cables to the solenoid, starter and primary case - you’ll be drawing more current, and the original cables are already woefully under-specced.  
  • You must have a decent battery.  
  • You may have to adjust the breakaway torque of the overload backfire device - we took ours from the factory standard 50lbs/ft to 75lbs/ft. This is due to the increased torque you are putting though it.



Upgrade the cables (Thicker ones) Don't use the prestolite solenoid, its crap. Use a lucas one for a Mini. If just replacing the two pole field coils for four poles, be aware that the prestolite has a built in fault that the rotor WILL wear into the drive end until the windings contact the end plate and then short out. Just putting a four pole frame into a prestolite will bring a slight increase in performance but will accelerate this rotor wear. The bearing modification i do stops this wear and frees up the motor giving it more performance. A two pole, bearing modded motor will out perform a fourpole bush motor.

Don't increase the breakaway torque on the backfire device. Its set at 50lbs/ft for a reason. to protect the starter motor.

Hi Peter 

who supplied you with your new 850 mk111 starter motor I have the same sluggish problems starting my 75 roadster 

TIA Keith 



Apologies Mr Shand to clarify I was directing my question to Mr Barrow.


That's fine as i also supply overhauled and improved Prestolite starters and Converted 5780 BN (harley) starters for Mk3 's

Sluggish performance from your prestolite starter will be most likely be the rotor wearing into the drive end plate and shorting out the windings, easily seen when the starter is dismantled.

PM me if you want to know more


Peter Shand   



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