Yea i know that will all effect it. and it will change from day to day. Unfortunatly i have no control of this. all the test so far were done in a 4 hour period and so the weather conditions should be pretty close.

I am using an 18-8 prop.

I do plan on checking the port timming i think i have that in test #11

As far as checking the deck height it really isnt that hard to do it with the calliper.

You got to admit it is pretty interesting that the older cylinder is the better performer. I had a suspicion this would be the case as it does have a higher compression ratio.

I dont know if my muffler is beter breating or not. i have never tried a stock one and the one i have now it the paragon muffler. it has two giant outlets. Some back pressure is desireable in 2 strokes though. it is possible to go to far and reduce performance.

Even with only 370 rpm gain the power output gain is pretty noticeable.

At this point i am inclined to say find an older engine with the single intake runner per side and the higher compression ratio and add a two ring piston to it. the two intake runners per side may be just fine but this cylinder has a much lower compression ratio.