take the nut off the flywheel and check the key, maybe it sheared when it died on the hill. Try some ether and see if it will at least pop. You can check the valve timing pretty easy, take the cam cap off and look at the timing mark on the flywheel.

should I be able to turn the flywheel by hand? I'm not sure how much compression these are supposed to have.
I do know that the cam rotates when I spin the flywheel, so I don't think the keyway is sheered completely.

there should be resistance at least when turning the engine over. Normally when the key shears it will still look and operate normally but it will throw the ignition timing off due to the shift of the trigger coil

I'll probably have to dig in more later this evening. Kids are back from the grandparents and the quads are hidden away. I'll have to verify visually the valve timing with the flywheel. I have to be honest I did have a hard time using the .005 feeler gauge with the limited access of the round plugs. I attempted a few times to where I thought the gauge was between the tappet and the valve. I thought maybe that I wasn't really getting a good feel on the gauge, so one time I backed the adjuster out until I got a good rattle on the rocker. Then by hand I turned in the adjuster until I felt pressure against the valve, backed it out about 1/16 turn and set the locknut.

I do need to actually verify the timing though. gotta pull the main valve cover off so I can see the cam gear mark.

The pickup coil may be bad. That’s the only thing left, but testing it requires pulling the side cover. You can try to ohm it out, but I have had more than my fair share of coils fail and still ohm out within specs.

nope, swapped the pickup when I swapped the stator. Everything comes off in the cover so it swapped as a working unit. My particular engine has the 6 coil stator assembly.

I know the only thing left is compression, and it was really the thing I thought for sure couldn't be an issue given the engine was running fine then quit without any catastrophic sounds. I'm going to set the motor to tdc, pull the spark plug and shoot some compressed air in the hole. That should tell me if I have compression or if air is leaking out the intake/exhaust or bottom end. (obviously have to take the oil fill plug out as well)

If I am getting no compression it makes me wonder if I floated a valve and "WHAM!"

-J

OK. I have a compression issue. I pulled the inspection plug on the flywheel cover and spun the crank counter-clockwise until I see the "T"

https://photos.app.goo.gl/jGsAycK3Q6nGTQ6y8
Then I verify I'm at TDC from the cam gear

https://photos.app.goo.gl/Yvo5kg2BPyGywYqQA

I pulled the spark plug and the oil fill, and shoot compressed air into the spark plug hole. I get air shooting out of the carb.

Then I rotate the crank 1 full turn. Again displaying "T" in the inspection port at the top of the flywheel cover.
The cam sprocket looks like this.

https://photos.app.goo.gl/zKRyzirziu65yfco8

Now I get air out of the exhaust & carb.

So... I think I have a problem. Any thoughts?
Without taking the top end apart, I think the intake valve is likely bent for reasons unknown. Just to prove to myself it wasn't an adjustment issue, I backed the valve adjuster all the way out so the valve can't close any further. Still air out the carb.

I think the head is going to need to come off. It's possible that the seat detached from the head, but a bent valve seems more likely. If it's just the seat, you should be able to press is back into place and peen the soft aluminum of the head back around it. If it winds up being a bent valve, you may be able to carefully straighten it back out, provided the face and sealing surfaces aren't totally wrecked. Sounds like you've got a bit of a holiday project. Merry Christmas, let us know how it turns out.

Ordered a new complete head on amazon. 1 day delivery. $47.

I'm hoping I can get it on with the motor in the quad.

Thanks again everyone for your help so far
-J

Contact the deal as it should be covered by the warranty.

Yea, I am a little annoyed at the responsiveness of the dealer. I've tried contacting them the past 2 days and no call back. I understand it's the holiday, and they are likely buried, so I haven't blown them up on this forum... yet.

I wanted to try and get this working for tomorrow, so for less than $50, it's worth it at this point if I can make that happen.

I'll work on getting a replacement from the dealer after christmas if this works out and have one on the shelf as insurance.

Christmas is saved. The head arrived around 8. Started working on it a little after 9, by 11 it was running.

The piston slapped the valve, put several marks in the piston that I was able to smooth out with a dremel. I had to remove the top engine mounting bolt and lift the engine about 3/4 of an inch in order to gain enough room to remove the head. I'm pretty happy I didn't have to take out the motor.

Pretty pissed at the dealer. Not even a phone call today. Good thing I know my way around engines.

I'm just happy we'll have 3 happy kids instead of 2 happy and 1 disappointed.
I am planning on bringing the other two in the shop tomorrow before they turn them on and adjust the valves on them.

-J

Guessing those valves were real tight then. Did you lash the other ones?

Glad it worked out well! Sadly there are not many dealers that provide good basic after sale support or stand solidly behind the warranty they like to highlight in the ads.

Glad to hear you got it sorted out miatawn2b. This was the worst case scenario I was trying to warn you about with waiting till Christmas morning to put them together. You managed to pull it all off in the St Nick of time..... good stuff.



Did you ever get the FNR issue fixed?