XT600 3AJ intermittent bad running
 

Hello all, my bike seems to have developed an overnight issue.
All seemed fine on the last use but a few days later the bike started to miss and pop only a few streets away. I rode back to my garage with it running bad and cutting out thinking it was a fuel problem. A few days later I went to take a look but it was running fine, so went to go out for a test ride and just got out of town and the problem started again and managed to limp it back. I've tried a few times now, sometimes it's an immediate fault and sometimes I can ride for 5-6 miles until it happens.
Today I've tried to ride it to get symptoms or some kind of pattern of what's happening but it's still totally random. I did keep trying to ride it out of town with it missing and backfiring and did notice on my return home that the silencer was super hot, it felt hotter than the front pipes and the indicator had slightly melted so guessed it had been throwing flames.
With it being so intermittent and random I am starting to think possibly something electrical.
Any thoughts will be greatly appreciated

Coil, clean carb, check sparkplug.

Thanks xtrock, I have swapped for an old plug I had and still same issue. Will get a new plug after the weekend. I am hoping it's a plug or coil breaking down.

a few other things to check

besides cleaning the carb, see that you get good fuel flow at the end of the tube entering the carb. disconnect it and let fuel flow into a bottle. if it starts to go slow at one point, you have a tank venting issue, making bike run lean and hot.

the power (also called charge) coil inside the stator can start working intermittently, specially when getting warm.

good guide on how to check your ignition

https://transmic.net/2016/07/02/faq/

Fuel starvation.

When an air/fuel mixture is very lean, it burns VERY hot and can make your exhaust glow.

Id be checking the carb first. Especailly the crappy filter under the float valve. I'd get rid of it. Use an inline filter instead.

AJ problems on mine
 

FWIW: Similar symptoms for me were crack(s) in the original intake manifold. Of course nearly the most expensive and most difficult to get to/sort out. Grrrrrrr


Regards, "Dr. G"
Author of MOTORCYCLE SE*, a spoof on Sigmund Freud, now on AMAZON digitalized (as many say should have been done to Freud).
keepcalm

a simple way to check the problem Ted is talking about is to remove the drain plug from the bowl, open the tap and see is fuel flows out freely.
part #21 here

https://www.ronayers.com/oemparts/a/...379/carburetor

if you get good flow out of the fuel tube from tank, but not so out of the drain plug, then problem is in the filter on the float valve seat.

part #10

Thank you guys, I'll strip down the carb at the weekend and start from there, don't really know why I've been putting ti off. I will let you know the results