If the books gives a table or resistances for the cdi then yeah sure, do that test. But if the cdi is firing the spark plug at all it's probably not the problem. I'd suspect the ignition coil or it's lead. Some modern systems with resistor leads or caps do have very skinny sparks that are hard to see in bright light.. If you have a timing light put that on and see if the spark is regular. And I suppose you have checked for fuel problems ? Isn't flooded ? Hasn't run out of fuel ? Getting fuel right into the carb ? Have you tried the carb drain screw at the bottom, it might let water out, or reveal a lack of fuel flow if the tap is on.

Im hoping, the engine seems okay 130 compression a little low but I think this had been sitting since 2019, there is a date on the CDI, hand written, im assuming that's when they bought the CDI, not sure if used or new, and am certain it never ran with the coil in upside down.

Yes I was wondering how many of these get put in wrong..

Looks like you might just have it up and running soon. 👍

Good eye Eugen, I didn't even notice the chewed up gasket, I am going to remount it and see if it works, thanks for the video p5200 I did notice that his was mounted like mine but the mounting tabs were lower in the case and the coil didn't stick up out of the case like mine, and Mech great information on how to test it. If still no spark I will check to see if it is putting out voltage and if it is I will have replace the CDI. I have read several posts of the same thing happening , put in upside down, It just amazes me that they didn't notice how the old one came out, and didn't even question their work and just give up.

in 20 years of mechanics I have yet to come across gaskets that need adjustments/modifications to fit...(except Chinese chainsaws)

sure it's the sensor upside down, if you look closely at the gasket you can see it is cut out so it can be fitted, which means the pickup sensor is fitted wrong

Oh I just realised what Eugen was saying.. Yeah good point Eugen.. it does look like it could get flipped over...

That core needs to be close to the metal tag as it goes past. Much the same as in older versions, a few thou is about right.. I suspect it's position won't be adjustable, so unless it's the wrong version it should be right unless it's an eighth of an inch away. A sixteenth of an inch would be about the max gap I would think..

You mean the metal tag is there ? It's not a magnet, just mild steel. If the tag is there then you need to check the trigger coils has a magnetic core. If the bike sat for a long time the magnet may have got weak. If it's a magnetic core coil, you should be able to get some very small voltage from it by passing a piece of metal closely past it.. the faster the better.. If it's not a magnetic core then it's the more modern type that needs power going through it to induce a magnetic field which then gets changed by the metal tag going past. The cdi detects the change of resistance caused by the change in magnetic field. It will work in one of those two ways, or have a problem related to which sort it is and how it's meant to operate. And finally, make sure there are no flakes, or little accumulations of rust powder, that could rise up and bridge the gap between the metal tag and the trigger coil's core. That will stop either sort working.

Thanks for the reply Eugen, im not sure, I have not had one of these apart before and that was my first thought when I saw it, appears it should be in the recessed area looks like it belongs there I am going to take some measurements and see where it lines up with the magnet on the rotor, the other way around. Mech my magnet is it tact looks fine, I am going to inspect it closer when I clean the rust off.

Most of the service manuals discuss the variable aspects of the clutch and drive system It's complicated and everything you change effects other things. If you are doing it then you really should download a manual and have a read, or try to get someone that knows what they are doing to give you a hand. There are some good books about the belt drive systems been written for snow-mobile tuning.