Well, its really late, and I cant really sleep cause Im thinking about the mods to this engine too much.
I just realized that my initial test with this engine was with a JXF 16-8 prop. After the new ring I havent compared it with the same prop or gave you guys any "real world" improvements. Tomorrow, Im going to try the 16-8. I also fixed my muffler. I also added another tube. (i think it was too much back pressure with only one tube)
So far the mods for this engine include:
1) bigger carb (WA19A "27/64" ) 2) made a 1/2" hole in the muffler to increase flow 3) Removed head and backplate gasket and used thinner ones (that three bond stuff doesnt work very well) 4) Increased exhaust port size and timing (by using thinner gasket intake was also affected) the timing is: Intake open 299 degrees Intake closed 62 degrees Exhaust open 107 Exhaust closed 255
Intake duration 123 degrees Exhaust duration 164 5) Frank bowman ring

Now for my question...
I checked the intake duration against my stihl and the POULAN is at 123 and the STIHL is 116. But the stihl intake opens about 7 degrees sooner. Should I advance the timing of the intake any more?
Has anyone ever messed with transfer port timing? If so, how did you measure the duration and if I advance it too far, how will it affect the engine?
thanks alot,
andrew

Here is the short video from today http://www.youtube.com/watch?v=luLYADYo3Ek