Ignition Gremlin

[Av8r3400]

When I say check the firing order, I mean the routing of the plug wires to the proper coil. That also means checking that the coils were wired properly to the correct ignition module wires and the plugs were hooked to the proper coils. Thus eliminating the possibility of 1/3 and 2/4 wire mix ups.

Rotax calls for .028" gap on plugs.

[WWhunter]

Yes sir, it was the plugs on the 912 XtraPerformance pistons I originally had in the motor that needed a smaller gap.
www.craftworks.biz/pistonsite/6318.htm

[Av8r3400]

It's a Good news - Bad news situation today.

Good news is that the modules checked out fine down at Lockwood.

Bad news is now I have no idea what the problem is…

[gregsgt]

The EGT climb doesn't make sense to me. Dropping a mag should make the mixture more rich and EGT's climb when the mixture gets lean...

I think it sounds like a wiring problem in the ignition somewhere. Maybe a bad switch or something.

[Slyfox]

this is my thoughts. when you get your modules back, switch sides, see if it changes to the other side, if not, electrical wiring

[Dave S]

Larry,

Don't know if this would help any; but, on single ignition engines timing can drastically affect RPM. If everything else is equal (thottle the same) advanced timing will result in a higher RPM......retarded timing will result in a lower RPM...retarded timing taken to the extreme (short of killing the engine) can also result in a big RPM reduction with the charge burning partially on the way out of the engine which would possibly raise the EGT.

When you mentioned 50 and 500.....the 50 almost seems like less of a drop than a person would normally get on Rotax. If considering timing....is there any chance that the side which drops off 500 and raises the EGT is running on a severely retarded timing setting?

I don't have a clue how timing is controlled on a Rotax. Don't recall if you have the soft start (which I believe retards the timing to prevent kickback) and I don't have any idea if there is any possibility of the soft start affecting the running mode.

Again, not saying that I know anything about what the problem is; but, thought I wanted to share this possibility in case it might play into the issue.

Wish you luck in solving this.

Dave S

[Av8r3400]

These are all good ideas and I thank you for all of them!

I should be getting my modules back tomorrow and further testing will commence as time allows.

(Dam day job getting in the way of my flying fun time... )

[Av8r3400]

Dusty,

I wish you good luck in the replacement of the modules. I hope it works as well as it did for me.

You mentioned earlier if there was an "aftermarket" option for these modules. I did extensive searching for this unicorn also and came up with nothing. Further thought on the matter lead me to feel that the money for the modules, even as expensive as they are, is cheap insurance for the overall safety of the operation of the plane. When all was said and done, I still feel it was money well spent.

I would ask you to consider looking back at post #12, telling why, when I did the conversion, I went to the latest model module, the 6x6. The newer module is more readily available and far less expensive.