I have been reading the different posts on the various things you can do to a stock 850 MK3 starter motor. The Old Brits conversion for 300.00 for the 4 brush 4 winding seems to be a good deal. Anybody had this done and does it work well?

Thanks.

Bob in Fresno

I have done several 4-pole, 4 brush conversions and use one on my own hi-compression 850 cafe racer. Short answer is it works. Heavy gauge starter cables are a must.

However, if the choice is to buy one for $300+, I would consider Dave Comeau's Japanese starter. I'm sure it is more efficient than the Prestolite, even with 4-poles.

Once you have the starter motor reliable, you will find the shortcomings of the sprag clutch.

I bought a new starter (not a rewound original) from Baxter Cycle. I think it was a bit over $300.00, but I am pretty sure it would spin a Mack truck engine. Bolted right up and worked first time I pushed the button.

I have been using the starter available from Norvil for a couple of years now with no problems - it is also a modern starter with more power and a better ratio. It spins the motor over fine. I had the 4 brush conversion previously and it didn't last long before deciding to throw the towel in, and it still wasn't as good as the Norvil one anyway.

Buy Dave Comeau's starter. It's plug-and-play, with new components and relatively modern winding technology. It's been on my Mk3 for a year now, and has never hesitated, much less failed. It's also lighter and shorter than the rebuilds being offered.

I tried a 4 brush set up on a mk3 i owned in the late 80s-early 90s, the starter motor is a prestolite and a simular 4 brush unit was fitted to mercury outboard motors of a simular vintage from what i remember we used the centre of the norton unit with the armature etc of the mercury, but the problem was a good battery i feel that with todays agm or gel batteries then this would work better.
Al

thanks for all the resonses.

Bob ib Fresno