hot n cold?

Just been for a ride on the XJ900 I noticed cylinders 3/4 hot as hell & 1/2 warm like you can touch the headers what yer recon? ho it was misfiring when pulling away in 1st to.

 

you pop the plugs out, ground them and see if their firing yet? can't imagine this being to hard of a prob to diagnose.

considering it's both cylinders, and if they both just started having problems at the same time, i'de assume electrical.

i never had to mess with it, but the ignition coil pickup, it has two sensors/magnets whatever, and i'm not sure how they function, but if you can can figure it out (figure if one side controls 1 and 2 , the other side 3 and 4. however they could be set up the same way as the ignition coils, someone here might know) that would be an easy thing to point the finger at if it's 1,2 and 3,4. but your ignition coils themselves control 1 and 3 then 2 and 4, so at first glance i don't assume they'd be the problem, but, hey, could be wrong. Just start going through whats involved. the more things you find that aren't wrong, the closer you get to what is wrong.

(i'm not familiar with the 900, engine and components could be different)

 

Low rpm misfire that resolves as the revs come up I'm usually liking vacuum leak for...

If you're sucking air from bad boots or gaskets, the corresponding exhaust runners will usually be cold at idle...