Centrifugal Clutch Probs

[Pat]

A clip on the clutch of my MS361 fractured causing a few problems i.e. embedded itself in the pump body. I have always thought the oil pump was not up to the job on this saw. It never seems to belt out enough oil. The nylon worm drive has had to be replaced previously too.

[GardenKit]

hi Pat. The MS361 is a robust, hard working saw, but in common with all others it does need maintenance to minimise the sort of problem you have had.

Regular greasing of the clutch needle bearing is essential. Dry bearings cause wear to the inner bore of the clutch drum, and to a lesser extent to the end of the crank. This wear, if unattended to, allows the drum to tilt, putting stress on the clutch segment retaining clips which can fail just as yours have.

The tilted drum also applies a thrust to the oil pump drive spring which causes it to wear the nylon worm. Once worn, it looses full drive to the pump which may explain your poor lube. The 361 usually has a good flow rate as long as the oil is not to thick.

A badly worn drum can also tilt sufficiently far to score an arc shaped groove in the pump body. When deep enough, this groove perforates the pump chamber and lube is lost.

I see a lot of these problems, its good for business but frustrating as they could have been avoided with a little maintenance.

[Pat]

Thanks for this and sorry for the slow response.