Chainsaw Repair

found a few more bits of information.

the carb area has to be close to the inake runner x-sectional area or the intake ramming effect is diminished.  a ratio of 0.7 or greater is the goal.

stock sizes: carb venturi area = 0.31 in2;  intake x-sect area = 0.43 in2......so 0.31 divided by 0.43 = 0.73 works.

same carb with larger port sizing:  carb = 0.31, intake area = 0.53......0.31/0.53 = 0.59 .......intake ramming diminished.


also found some saw motor temperatures from blair page 391 figure 5.25 graph.

crankcase internal temp range from 140F to 248F.  average about 212F.  (so, most vaporization is happening in the cylinder, not the c.case).

intake runner internal from 68F to 122F. average about 104F.


have enough info to include corrections into the formula now.