Forum

[Norm]

Biggest problem I am finding is runnout in the drive shafts. A motor that has been giving issues for some time now, and it was a particularly good motor originally and fitted with a Carillo rod but ran into difficulties when the rotor exploded and bent the drive shaft. Trying to source a driveshaft with minimal runout became quite a challenge but eventually after checking 10 we ended up selecting the one with the least runout.I pressed the crank together, put it in the lathe and it was dam near perfect, so all the other drive shafts are bin material. The interesting thing is that this shaft was from a factory built engine which proves they used the best and all the ones that weren't up to scratch they sold off as replacement parts.

[Les H]

Hi Norm. Alpha Bearings told me that the Indian cranks were assembled, roughly lined up, big-end nuts tightened and then the whole assembly put on a lath where the mainshafts were machined to get the whole assembly to spin true! They just could not align the cranks any other way reliably. I guess they would have had to have had the mainshafts slightly fatter to start with to allow metal to be machined off them down to the correct size. One would imagine that the flywheels would have had to be done the same way too.

[Norm]

Les,
I have heard that was the way that the factory set the cranks up but spinning the crank in the lathe with the con rod flying about isn't practical in my little shed.The big problem I find is that a lot of the shafts have up to .6mm runout in the shaft and this then gives a lot of problems with the stator runout

[Norm]

Should be rotor runout

[Alan R]

Ah, beat me to it. If you have 0.6mm stator run-out you HAVE got problems.