I have an Fl250 I picked up this summer. I think it's an 84 ( Manufacture date 11/83). I have only riden up and down the street, until today. I took it out into a pretty cool riding area for about 45 minutes. I did stop after about a half hour, only for one minute, and started right back up. When I stopped the kill switch worked fine, as it has all previous times I've run the machine. This time I drove it into the back of my truck and hit the kill switch, it didn't get killed. So I unplug the plug wire, still running great. Pulled up the choke on the carb, slowed a bit. Finally I gave it a little gas and it finally shut down. Is it possessed? I thought I had seen a post about this before, but couldn't find it.

You have the FL250 diesel version.... Really, detonation has turned your Engine into
diesel, something hot is igniting the fuel not the spark plug or the quality of the fuel
your running is poor.



It has a CDI (Capacitor Discharge Ignition) right? Non adjustable timing so we can rule out advanced timing..
that means poor gas or excess carbon build up creating a hot spot.

Try some fresh 91 or 93 octane gas mix see if the problem goes away.

If you never been inside this Engine now might be a good time to take a peek inside.

I'll try the new gas route tomorrow. It is a CDI (Capacitor Discharge Ignition). The previous owner told me that it had a shaved head?? He bought it from a friend who had it set up as a sprint car. I'll let you know if the new gas works. Hopefully.

How did you make out?

Didn't get to it yet. It's rained every weekend. Now its snowing out! A little early for me. Tomorrow should be clear. I was reading in the manual about cleaning out the carbon every 12 months. Doubt that's happened. I'll clean out the exhaust port & try the gas. How well did the rear suspension on the Challenger work. I'm hoping to start to put mine back together starting this week. I'll post pics, as I know most of the 250 guys are curious about the details of various rear suspensions.

Thanks

The Challenger suspension was 100% improvement over the solid axle but was limited
to about 4-5" it was great for general riding I didnt do much jumping but suspect you
would need to custom tune the shocks for jumping then want another setting for
general riding.

I seen alot of potential for that suspension the one I had was not setup right, it
had no droop all the travel was when you compressed the shocks, with new shocks
of the proper stroke I could have got 4" droop and 4" of compression for a total of
8" of travel over jumps, I never messed with it because I probably needed to buy
FOX air shocks like my Pilot has ($400 +) then dial them in, the kids out grew it
so it was time to sell.

How about posting them pics you talked about since your rained out?