I use Zinger 20X10s on my Brison 3.2s. The RPM is 7200. With 20X11s, I get 6800. That 22X10 sounds like a lot. I use 87 octane gas with Sthil HP mixed at 50:1. The CH ignitions are great, but like everything else, they can go bad. I never go to the field without a spare and in the past few years have had to replace one. Check the sensor connector. The solder joints on the male and female sides are prone to failure and it's hard to detect. You will have to remove the heat shrink tubing to find out. I've had several failures there and had to resolder them. Here's a link to a classic video that one of the regulars here posted. It will help you with the timing. It should 28 degrees BTDC at high speed and around 4 degrees at idle. Also check the ball links on the connecting rod from the carburetor to the timing ring. Those threads get stripped sometimes. Dan.

http://www.youtube.com/watch?v=GBXFp...?v=GBXFpxWg7vY