#4 not firing (96 Kat 600)

[Staerke]

So my #4 cylinder isn't firing.
It occasionally does fire, but usually doesn't. The exhaust pipe is warm, but not hot like the other pipes.
So far I switched the plugs with a cylinder that was firing, no difference. The plugs looked good, at most some carbon deposits but for the most part they look normal.

This weekend I'll be cleaning the carbs, adjusting valves, etc. (fall break, have time to do it, w00t.) I'll see if that fixes it.

Is there anything else I should be checking for when I take it apart?
Thanks for any advice.

[Newbie2it]

Its not your plugs, Most likely its your pilot jet on that cylinder... Clean the carbs. Pay special attention to the pilot which is what gives you the fuel at idle on up.

[Staerke]

Ok so cleaning the carbs, I can't get the bowls off of 2 and 3 (screws are jammed up, just stripping them at this point)
And I can't get the emulsion tubes out of 1 and 4...just don't know how.

The Pilot jet for 1 was floating around, not even screwed in. That could have caused issues. I know a shop cleaned it last, don't know what kind of job they did. Looking shoddy. Wish i could get 2 and 3 open to see how it looks.

Left them sitting with seafoam in the bottom of the bowls (poured some in the fuel hoses

Now #2 is oozing black crap. At least it's doing something. Wish I could get them open.

[bubba600]

I used needle nose vice grips to get my bowl screws out, and replaced them with allen head bolts of the same size. To get the emulsion tubes out, i took the main jet off, and screwed in a bolt of the same thread and size a little bit, and just pushed on it and they popped right out.

[cleankat96]

I used needle nose vice grips to get my bowl screws out, and replaced them with allen head bolts of the same size. To get the emulsion tubes out, i took the main jet off, and screwed in a bolt of the same thread and size a little bit, and just pushed on it and they popped right out.

+1

[Newbie2it]

+ 1 on all said, Emulsion tubes, you can just unscrew the mainjet a bit and give it a whack to free it instead of hoping to find a bolt with the right thread. Vise grips to remove the stripped screws and take one to the hardware store to match them up with stainless steel of equal length.

Either way, considering one had a pilot floating loose, They didn't do the job right from the get go and the pilots were never cleaned properly to start, One can surmise. Break open the other bowls... Follow the Carbs 101, when your done, Do it again for good measures. Do a rough visual synch of the carbs before reinstall and then put her back together. Bet its a different beast when your done. But the pilots were definately an issue since one was a floater. Check float heights before you reassemble everything and go "D'oh" Better to do it wholey now, then half azzed and wishing you did it all then.

[blackice2242]

make sure it gets spark to rule out its not the plug, or coil

[kevin2502000]

make sure it gets spark to rule out its not the plug, or coil

I re-read OP, he does state he switched a good plug in but doesn't mention that it actually had spark on that lead, good point.

[Slofuze]

If #1 fires...... it's not your coil (on my Kat 1&4 are on the same coil)...... maybe a bad plug wire to #4?? I'd swap in a new plug....and try again......or at least make sure you have spark coming through. Just my thoughts.

[Staerke]

It was/is the plug, namely the cap that goes over the plug. Simple fix, just need to replace it. Stuck a ohmmeter in there and there's infinite resistance through the cap. Can't wait to get it fixed, the engine sounds so great now that the carbs are clean.

[Staerke]

And...Fixed

Runs smooth as butter. So happy right now.