Cam Runout question

Putting together a MkII 850 engine,( so no rotary disk and spring on the end of the cam) and I am finding way too much end play on the cam.
The Cam thrust washer is in place and with the Camshaft sprocket bolted on I have 32 thousands end play.

Can't find a spec in the workshop manual for this endplay on the Cam.
Is it possible to shim the back of the Camshaft sprocket?
Thanks,...

Yes, I did this. I was trying to reduce endplay that was causing a PowerArc EI to loose sync/focus through its optical sensor and the encoder wheel.

I recall bringing it to .010". Although .032" may not be uncommon, it sure would be too much for the PowerArc. I am done with the PowerArc but I like knowing the cam endplay is where I have it now.

Just to be clear, "runout" would indicate radial play like warn bushing, cam journals or bent. PowerArc, doesn't like that either.

I have not been into this section of my Combat, but suspect I had similar problems.
After much frustration, I replaced PowerArc with a Trispark and the improvement was immediate and substantial.

Thanks Guys,
My plan is to put a Pazon ignition on this bike, so this side to side movement would be very bad I believe.
Unless there are others out there with with experience or advice, ...I will be looking for a shim to go between the Cam sprocket and engine case that will put the run out on the Cam in the 10 thou range.
Thanks again pete.v & tomspro.

AZScott said:

Thanks Guys,
My plan is to put a Pazon ignition on this bike, so this side to side movement would be very bad I believe.
Unless there are others out there with with experience or advice, ...I will be looking for a shim to go between the Cam sprocket and engine case that will put the run out on the Cam in the 10 thou range.
Thanks again pete.v & tomspro.

Click to expand...

Just to add there AZman, I have heard said that some feel the tach drive tends to keep the cam pulled over to the right. I don't know about that, but I have now blanked the tach driven, using an electronic tach, so it mattered to me to have a consistant cam position thinking that if it, cam drive, did keep the cam pulled over, I would have that issue covered. Although it seems to some that it doesn't matter, it seems to make sence to me.

You can add to that, the cam and lifter contact will have a no more than + or - .005 tolerance in the linier dimension. Who know, maybe that doesn't matter either, but it seems to make sence to me.

If tach drive installed then cam is pulled to TS so only need to shim/washer TS to set cam running position as they all will be easy to shift back/forth a good bit when not turning.