cylinder not firing

My #4 cylinder isnt firng right. There's a good sprak so its something else gas/air related. I am in the process of working out that out.

Its been like this for i dont know how long, i only noticed because I swapped in a 4-1 and that cylinders pipe wasnt blueing. :dry:

SOOO, I was wondering if it running on only 3 of the 4 cylinders for who knows how long would cause any damage?? or other problems down the road? Is it ok to ride as is for now or should I not until its fixed??

Maybe that cylinder is running a bit rich. Is that exhaust pipe coming out of that cylinder even hot? Use the drip water test on it while the bike is hot.

no after warming it up its not hot at all really, to the point where i am able to touch it without burning myself. it a little hot but mainly from the heat of the engine. Wouldnt dare poke at the other header pipes.

ill sort it out eventually, but really my question is it ok to ride for now here and there or should I avoid riding all together until all cylinders function properly.

I would fix it.. You could twist the crank. It is possible that the plug isn't firing under a load.. I would replace it just to be sure.

which bike are you working on, you have two in your profile.
you say you are getting fire to the plug, is the plug wet with fuel?, if not then I would think a carb issue may be causing the problem,, but there needs to be a bit more work done to determine what the real issue is

Good thing is, it is probably an easy fix.

But is it ok to ride as is in the mean time if requires a little carb fiddleing??

kz1`000

just swapped the plugs, but i only had a BR8ES not a B8ES. But didnt think that would make a huge difference. I can smell gas on the plug, and it looks like...

squints wrote:

But is it ok to ride as is in the mean time if requires a little carb fiddleing?? kz1`000

It's too soon to fiddle with the carbs, and would just complicate the diagnosis at this point where ignition and compression are pre-requisite determinations.

#4 plug is most likely fuel-fouled beyond recovery. It might look okay, even newish, and perhaps even spark under no compression -- but it is most likely doornail dead.

Would first install brand new sparkplug in #4.

Next, swap #1 and #4 plug wires -- put #1 wire on #4 plug and #4 wire on #1 plug.

Test run engine to see if non-fire moves from #4 to #1. The non-fire will either continue on #4 or move to #1.

Use water spray bottle to mist exhaust header pipes while engine is running. Do not touch any of the pipes. Hot pipe from firing cylinder will vaporize the water spray with immediate sizzle. Non-firing cylinder allows water mist to just run down the pipe.

Post test results so we'll know how to best proceed.

Good Luck!

and try nippo denso plugs not NGKs

NGKs seem very prone to fouling/dying these days.

ok patton, before i rip everything apart, youre sayin to swap the #1 and #4 ignition cables and plugs. To do this I would 1)simply unscrew cable from ign.coils and swap cables Or 2)are you saying to simply reroute the cable to the different cylinder leaving the connections at the ig coil the same.
And to clarify further (that I'm givng rightinfo), while sitting on bike, cylinders are (L-R)1-2-4-3...

squints wrote:

ok patton, before i rip everything apart, youre sayin to swap the #1 and #4 ignition cables and plugs. To do this I would 1)simply unscrew cable from ign.coils and swap cables Or 2)are you saying to simply reroute the cable to the different cylinder leaving the connections at the ig coil the same.
And to clarify further (that I'm givng rightinfo), while sitting on bike, cylinders are (L-R)1-2-4-3...

Would first install brand new sparkplug in #4.

Don't remove the plugs -- just leave them in.

Next, swap #1 and #4 plug wires -- put #1 wire on #4 plug and #4 wire on #1 plug.

The plug wires from the coil to #1 and #4 plug are usually long enough to allow swapping them for each other. But if the wires aren't long enough, let us know.

Test run engine to see if non-fire moves from #4 to #1. The non-fire will either continue on #4 or move to #1.

The results of this test will provide some diagnostic clues regarding the ignition.

Good Luck!