Chainsaw Repair

the good things i learned: 

-headlight restoration kit will work well on the plastic lens (500 grit; 800 grit; rubbing compound)
-throttle body cleaner is the only thing that dissolved 20 years of crud on the gear strip
-dental pick removes stuck metal shavings which you cannot see, from the gear strip (fixed my return to zero problem).

the bad things:

-the screws will not come out no way - no how on mine, without stripping the heads or breaking the screwdriver.
-the two screws on the top of the caliper, next to the lock, control the tension between the gears.  (one of these screws was loose).
-the throttle body cleaner can and will seep below the lens (dial side) and render it permanently cloudy.

-joe

fixed my clouded up lens problem with my old calipers.

can't recommend this fix, but can say it worked for me.

my lens clouded up from brake cleaner a while ago while trying to fix the calipers.

before and after.

i twisted the screwdriver to remove the lens....would not suggest to pry.

I use a set of mics to measure drill bits .I have a lot of tap drill sizes commented to memory  .Those I don't it's just one thread spacing subtracted from the screw size . Usually close,is close enough depending on what it is .