Av8tor77. It is really interesting that you have had such a large gain in power output indicated by your rpm gains. I am fussing with a ryobi I have converted a couple of years ago. Its been a while but i think it is a long shaft with 2 rings. I have the good backplate that has the reed valve flush mounted. The best I can do on a stock set up with a paragon muffler and stock ignition is 6450 rpm. this is on a 18-8 prop. I am wondering where yours would be with a 18-8 prop?

I would also like to know
1. what brand of electronic ignition are you using? Where did you get it as I also want to set mine up with the electronic. Hobby kingdom has a replacement set up for their engine that can be had complete with shipping for under 40$

2. How did you figure removing the gasket droped it .035? My case has a couple of small ridges cast into the case where the gasket goes to aid in gasket sealing. Did you also remove these ridges?

3. When you drop the cylinder gasket I understand it ups compression which is good. compression = power. However how does this change the port timing and how does that affect power output? I noticed you said you changed port timing to i tink it was 152 degrees. How did you accomplish this and could you show pictures of this mod? why did you use 152 degrees. How was this number derived to be a good point for port timing?

4.Did you do any modifications to the reed valve plate other than setting the reed valve stop at 1/8 inch. I think i read somwhere you decreased the lower end chamber volume. Is this true and how did you do this if so. again pics please lol.

5.you say you used an 11mm card. I am asuming the 11mm refers to the venturi size? I have a 12.8mm carb on the way. Was this gain in increase also due to a larger carburator? Was the original rpm number with the small stock carburator? Do you have the number off of the carb and where did you get it?

6. What did you do to the flywheel for the elecrtronic ignition and how did it affect balanceof the engine?

I have seen somwhere that there are two different timings of these engines. the one with standard timing you will see if you put the crank keyway straigt up twords the cylinder the crank rod journal will be straight up also. The one that is considered higher performance has a bit of advance in it. On this model if you put the keyway straight up the rod journal will be more to the left side when viewed from the top with the back of the engine to you. It is possible that your vibration problem may be due to this if you did not use the original flywheel that came with the timing of the engine. If you use an aftermarket electronic ignition with the hall effect trigger switch then this stock timming is unimportant as you canset it anywhere you want anyhow.

Thanks so much for all this info.