An educated eye ?

[Whistler]

Visual examination of internal assy. revealed two scenarios , same model saws but obviously a standard model vs. 'super' . During routine maintenance I just happen to have the mufflers off 2, 80 jonses' and did a carbon check of the exhaust port and piston tops. One piston had about .090 exposed at bottom dead center and the other had .025. The .090 saw has 200#comp and the .025 has 240 . Yes that's right , 240 . These model saws were hell on starter cords . Why they didn't have comp releases is beyond me, but why the difference in factory dimensions ?

 

[HUSKYMAN]

Is the piston with more compression all carboned up, possibly raising the compression ratio?

Also did you do the compression test with the throttle open?

 

[Whistler]

Huskyman , no carbon to speak of , throttle closed . There is an obvious difference in the height of the piston at bottom of stroke . Just wondered why manufacturing would do that . Didn't / won't disassemble to find out what it is , but it is either a different piston height , cylinder height or connecting rod length . It sure seemed odd looking ! Please bear with me on this and remember , I am a little more than a low-tech operator but will do extensive maintenance .