How do you compress the chain tensioner piston?
 

How do you compress the chain tensioner piston? And what should I use to hold the piston in place

C-clamp. The new one I bought way back when came with a pin to hold piston in compressed position.

A C-Clamp??? Won't the chain housing get in the way? The chain tensioner is still in the motor.

Just curious - why do you need to compress it then?
It is simple to take it out (from memory - it just slides on). So why not just take it out, submerge it in a bowl of oil then compress it?

what I did...and it was a PITA
submerge in oil and get all the air out compressing with the giant size channel locks...Craftsman.

put up near the shaft and ramp and slowly compress with the Channel locks..then slide into place

I wish I had the time to make a tool to compress that doesn't slide off the top of the piston...but I finally got it done.

I'm sure there is a better way...there must be

Compress v-e-r-y s-l-o-w-y in vise. When ram is compressed insert pin to prevent ram from expanding.