Bike Dies @ Speed. Ignition????
 

The local trails in my area are just a quick 1/2 mile ride down the road. Yesterday while traveling about a constant 50mph down the road my bike just dies and starts the exhaust brake sound created by the turning cylinder without combustion. This isn't the only time this has happened. I've been changing out spark plugs about 1 every ride lately b/c this has been happening. I had assumed that I had a "running rich" issue b/c the bike has started to smoke a noticeable amount more. I didn't think a faulty ignition could cause smoke until I spoke to a GasGas dealer the other day. He said tha an ignition that is on it's way out can cause a weak spark and result in smoke. Is this true? Everytime I change out the plug it fires right back up.

Go through all your connections, clean and dielectric grease, including the coil ground. Next, check the coil HV wire at the coil and the plug cap. The HV lead simply threads onto a self tapping stud in the coil and cap. This could be loose and/or have some corrosion from water getting in. Cut off a few mm of the wire on each end and rethread into the coil and cap, sealing with a little RTV.

cut-out
 

My bike had a semi-similar thing a while back where I would be flying along near wot and then it would cut out just like I was holding the kill switch. It turned out that there was some varnish flakes in the carb bowl that were clogging the main circuit when the needle was far enough out of the jet to allow it to cover the bottom of the orifice. Now I drain my carb bowl after my ride!
Nat