Best starter motor for 2.5 diesel?

[Tony x]

Hello,
Our Bongo has the heavy duty starter (as per the north Japan model) fitted that works just fine generally though struggles a bit if the starter battery is a bit low.
I happen to have the standard starter motor as well. Is there any advantage to fitting it?

The Bongo has a leisure battery, not the standard twin starter battery set up it came out of the factory with.

I believe the standard motor is 2kw and the heavy duty one is 2.2kw

My thinking is that sometimes the starter battery gets very little chance to charge when driving due to all the devices attached to the leisure battery and although the Williton kit prevents the starter battery being drained too much, it can still be left a bit marginal. Thus I wonder if the standard starter would work better due to the lower demand it puts on the battery.

[Simon Jones]

It's possible either the starter battery or the alternator is not 100%. Your idea of fitting the standard starter motor is probably is good one as the reason for the twin batteries is to ensure there is enough oomph to run the heavy duty starter and additional resistance of a cold engine.