Engine miss, 1811

[yeeter]

Am going to chase the wires - had that one happen on a different tractor and may have a spare wire laying around here to try.

But here are some videos. Both sides reading about 75psi on the compression test. Not sure what that means, I have heard here that there is a compression release which makes a compression test tricky to interpret. But both behaving in the same way so this seems good.

Then today when I pulled the wires it would keep running on the opposite. Put a screwdriver in the wire and let it jump to ground, and seems to get spark both sides. But not running well at all even with both wires in place.

Yesterday when I pulled the left side it would die completely (not firing on the right). Or maybe I am dyslexic. Either way, only one side was firing.

These videos are of the spark on both sides, then the compression test on each side. I was trying to juggle the camera while also pulling the wires, so they arent going to make the silver screen any time soon....

https://www.youtube.com/watch?v=cuWn54PJMMY

https://www.youtube.com/watch?v=Ov9j4BGcCKw

spark right side:
https://www.youtube.com/watch?v=iMUulVyGTKo

spark left side:
https://www.youtube.com/watch?v=MvSkGlJP46Y

(not sure why this video clipped, but did the same thing with the screwdriver and it jumps to ground similar that the opposite side does).

I should do that with the plugs not just the screwdriver...

[J-Mech]

Originally Posted by FrankF3

Jonanthan, I was referring that since the current path for spark involves both plugs, if one wire opens on one plug it will kill the spark on both .

Only if it is a dead short. An "open" wouldn't cause it to lose spark on both sides.

Originally Posted by yeeter

Both sides reading about 75psi on the compression test. Not sure what that means, I have heard here that there is a compression release which makes a compression test tricky to interpret.

No compression release on the Mag twins.


Try taking your side panels off to work on it. Makes life a lot easier. There are also better ways to check spark than with the engine running with a screwdriver. Good way to get bit.

It doesn't look like to me you have weak spark. At 75 PSI compression, I'd say your miss is "other issues". Blown head gaskets perhaps? Dig deeper.

[yeeter]

Messed with this some more. Seems to have magically fixed itself! (never a great feeling when you cant point to the exact problem)

What I think 'might' have been happening. That right side plug wire end was a bit rusty. This might have been preventing a good connection. (Roland was onto this)

But putting it on and off a bunch of times may have scraped it up to where it made a good connection again.

Or maybe not.

But its running ok now. Actually running great (really like this tractor).

I should just replace the wires. Anyone have a wire set recommendation?

It looks like a PITA, do I have to pull the tins to get to them?

We will see if it starts misbehaving again...

[J-Mech]

Wires are non-replaceable. Have to replace the whole Mag. Yes tins have to be removed, engine pulled.

For the record, I stated the poor/ rusty connection at the plug before Roland did. Make sure you read all posts.

[yeeter]

Originally Posted by J-Mech

For the record, I stated the poor/ rusty connection at the plug before Roland did.

mea culpa mea!

You all know 1000 times more about these machines than I ever will, thanks for sharing your knowledge. Im learning.

Fingers crossed that this resolves the issue. But Im not going to be shocked if it starts acting up again. We will see.

A long time ago I used a never seize grease for high temps. Believe it had nickel in it. Was wondering if it would be useful to put a dab of something like that on the ends (nickel for electrical connection and also prevent corrosion)

Im not excited about replacing the mag/pulling the engine. Uggh.

[J-Mech]

You should use ani-seize on the threads of the plugs, but not on the connection. You can get a tube of dielectric silicone for the connection. Just put it in the boot and slide it on. It keeps water out, but doesn't necessarily help with the connection. If your plug end is corroded, you can replace the end without replacing the mag.... if the wire is long enough.