MXU 270 no spark

[jpz]

Hello all,

Working on a friends MXU 270 which appears to have no spark.

When cranking the engine with the plug connected to coil wire, and touching the block there is no visible spark.

Changed plug, and we have the same result.

Checked fuses, and they are all good.

I ran a continuity test on the primary coil leads, and I'm seeing resistance of 1.9 ohms, this seems low to me, but I cannot find information to confirm if these readings are good/bad.

I ran a continuity test to the secondary (spark plug) and I'm seeing resistance of 2.2 with the cap installed, again this seems low to me.

The only workshop manual I could find was for a Mongoose/KXR 250, and going by their coil specs, the coil I have appears to be bad but I'm reluctant to buy a coil since I'm referencing specs for a different ATV.

Any input would be appreciated.

[jpz]

So I'm continuing to work on this MXU 270. Upon further testing with a calibrated meter, I am getting resistance readings closer to the workshop manual. They are slightly below, but much closer than I originally got.

I have also bench tested the coil, and I'm surprised by how faint the spark is. I had to turn most of the lights off in my shop to actually see the spark.

I'm curious if anyone here has had reason to check the plug/coil by cranking the engine with the plug touching the engine?

If so, can you tell me how faint or strong the spark you saw was?

I'm still curious is this coil is bad, or bad enough to not run the engine.

Any help would be appreciated.

[airshot]

They make a small tool called a gap checker.  It installs between the plug and the plug wire.  There is a gap that is adjustable so you can see the actual spark and how far it will jump ( the adjustable gap). We see them alot in the marine business, but have used them for all my gas engine testing. Your spark should jump at least an 1/8" gap and should be mostly blue, a really yellow spark means weak....  Best I can help you with...