Bill Carpenter's add on easy start system uses the original flywheel...Works fine...Kinda blows the theory about magnet size passing under the sensor,,,

Got the prop adapter finished, put the prop on the engine and started flipping it. After about 8-10 flips I got a pop. There is no choke on the engine so I had to use the thumb for choke. After a good choke and a few more flips it started spinning.............backwards. I checked the timing again and it seems that it is set about 8-10 deg BTDC. It is a Melody iginition off of a MLD-28. I checked this by using the original flywheel, it has 24 fins, 15deg between fins. the ignition fires consistantly at one point about 2/3 of one fin away from tdc. I beleive that the MLD iginition is suposed to be set at 28deg btdc. Does anyone know the set point for MLD ignition?
I did find that when I spin the flywheel backwards the ignition fires at a different location, about 10deg on the other side of tdc. Only one of the two magnets actually triggers the iginition.

MLD sensors are typically set around 35-40 degrees, they run much better set at 28. What the sensor is doing when you turn the engine over backward is normal. Are you sure you set the timing while turning the engine over counter clockwise as viewed from the front? What the sensor recognizes while turning slow by hand may not be the same as when it turns more quickly, the two large magnets may create a field that is confusing it.

I reset the timing to as close to 28deg as I can(without a degree wheel). The engine ran much better. It is to dark to get a tach reading but it sounds good. Also running the muffler off of the saw. I do have an issue though. I can't seem to get it to run at high rpm, it has a terible miss. I had the same issue on the MLD28 but it went away when I mounted the engine inverted. I tried to wiggle all of the wires around the sensor, make sure the plug cap was tight on the plug, adjust the high speed needle lean and rich with no success. After about 24-30 oz of fuel I got it to peak out a couple of time for just a second or 2. If I run up the rpm slowly it is better but quickly starts missing again. It is more odvious above about 5500rpm. At idle and lower speeds it seems very consistant.
What can I do besides buy a new ignition? Is it possible the magnets are confusing the ignition? Remember that on rare ocation for a few seconds it will peak out and then start missing but mostly just start missing above about 5000 rpm. I do not have a spare pickup magnet to test with. On the MLD the issue is there also when the engine is cold and seems to get better as the engine warms up and went away when mounted inverted.

It's hard to tell what might be going on there but I know the Melody ignition systems are always suspect, always have been. Since you had similar performance with it on the engine it was designed for I would toss it. You could also try getting rid of the flywheel, put a 3 or 4 mm magnet in your new prop hub and make a new mount for the sensor so it could operate the way it was intended.

I have suspected this ignition for a long time but since I have never mounted the engine in a plane it has not been a issue. Add to that it sometimes runs just fine and has never failed to make an engine run.
A guy here at work who tunes motorcycle engines said to close up the gap on the spark plug because a weak ignition can miss at higher rpm and a tigher gap might clear it up, at least worth a try.
Maybe I will steal the ignition off of my RGCF 26 and try it on the saw engine.

Tightened up the gap and it runs great. Took some begging to get my wife to come hold the flashlight so I could get a tach reading. With no muffler I was getting 6600 rpm on a 20x10 Top Flight Power Point wood prop. Not as much as I would have liked to see. Thrust calc says just over 3hp. How does this prop compair to others? Is it worth trying another prop type/size? Engine has awsome compression and a giant carb. Short of tuning the carb some more I don't think I am going to get much more. I would want to see at least 7200rpm to make it worth it. Will try some more tomorrow. Carb is hard to tune because the needles point toward the prop and I can't get a grip on then to turn without a screw driver. I have to kill the engine to make adjustments. Will try again with the stock muffler but I think it chokes it off quite a bit. Hard to get a good idle with no muffler.
As a side note I was watching the exhaust with the muffler off. At low rpm I see a pretty large blue f'lame, at high rpm the flame turns yellow and gets much smaller. Does this mean anything?

Still hoping to find someone who can tell me how the Top Flight Power Point compairs to other props of the same power range. I an not set on using this prop just using it for a benchmark and it doesn't seen to perform well enough. Will I see better performance out of a 22-8 of other brands?