help with coil

[art]

can anybody help me? I need to know how to test my coil to see if it is ok .I still have a misfire problem an cannot find the problem.I have replaced the plugs an wires ,desmoged ,an removed the carbs an cleaned them

[Patrick]

What kind of a mis-fire problem are you having?? And, on which cylinders?? And, at what engine speed?? With-out knowing any more,,and not trying to be a smart-ass,, I would still guess that your your mis-fire is fuel related.. When you pull plug wires[and ground them] to look for the dead cylinders if you hear the spark jump and lose RPMs ,, thats good cylinder.. If the spark jump can be heard but the the RPMs don't change,, thats your bad cylinder,, but,,the ignition system is OK.. If your not getting high tension voltage to the sparkler then you have an ignition problem,, remember that one coil fires two cylinders.. Front coil runs cylinder 1 and 2, middle 3 and 4, back 5 and 6..So a bad coil should kill two cylinders..

[Robert]

The easiest test of the coil is switch it to another set of cylinders then see what happens. To go further we need more info.

[art]

My #1 cyl. is mot firing  at rpms below 3000 I am going to switch coils an see if there is any change.All the vac. lines ar good with new hoses .I am getting spark but I was wondering if the coil was not giving out a good strong enought spark to run at low speeds if that is possible.I have had the carbs out an cleaned the bowl area an the jets without any change in my performance.It misfires the same after as before.I also checked the valves for clearence an they are good.at idle the engine is poping from the right side where #1 is

[98valk]

I was having the same problem. try your intake o-rings, get viton http://redeye.ecrater.com

or
it might be that the vacuum diaphagm of the oem petcock is worn out. This ended up being my problem, even after only 18-19k miles, when the bike started running inconsistant.

search my handle for recent posts on after market rebuild kits and the use of a "snubber" in the vacuum line which will almost eliminate wear of the diaphragm.

did u check for spark with the plug lying on the head?

[art]

I did check the petcock an it looks like new an I put a vaccmm on it an it worked  good I just switched coils an the misfire is still on 31 cyl .no change .I an going to pull the carbs again an work on them.I will bring them to a shop to get new jets an install them myself.I want to learn how to do it myselfan besides it is cheaper that way.there are no good honda shops around here anyway.thanks for the help.Art

[art]

I ment to say #1 cyl I do not have 31 cylinders

[Robert]

Art is it popping through the intake or exhaust? and have you tried a new spark plug? If you haven't done this then try this before you pull the carbs. Other things to check may be a bent or tight valve or check the rubber tube that goes between the carb and the intake. I have seen them loose or not put on correctly and let air in that way.

[98valk]

I did check the petcock an it looks like new an I put a vaccmm on it an it worked. .Art

pull the diaphragm out and look at the center area with a 2x- 5x eye piece. Look for the rubber material to be gone and just the base material will be there.

did u have the top of the carbs off? slide diaphragm mis-installed or a tear.
I had the same issue, all my troubleshooting led to the petcock, I did everything including pulling the carbs and checking the inlet screens to the bowls, nada. cheaper to thoughly cheak and fix than pulling the carbs. petcock diaphragm was the issue in my case.
A reason this shows up on the front carbs is because they can run leaner than the other ones due to their secondary configuration for fuel supply from the middle carbs.
good luck.

[gregc]

  Start it up, let it idle, spray some carb cleaner around the intake tube, and o ring area.  If it picks up rpm or smooths out you have a vac. leak in that area. I would try that before I tore the carbs off.

[Ricky-D]

Before you start going off in a frenzy I would suggest you make sure the ignition is 100%.  To blindly start messing with multiple things will eventually cause you to spend energy on things not connected with the problem you are experiencing and can actually hide the real problem from you  causing your blood pressure to go up thirty points.

[John U.]

I had 2 cylinders not firing at idle and the bike ran very rough below 3000 rpm, but real strong above. It proved to be clogged slow jets caused by rust in the tank. I replaced the 35 slows with 38s, cleaned and sealed the tank and added a fuel filter. All is well. The sediment in your fuel bowl should give you a clue, a flashlight and inspection mirror will tell the condition of the tank. If rust is you problem, cleaning the jets won't fix it for long. Will it run and idle better with the choke on?

[Madmike]

If a coil is bad you will lose 2 cylinders.

Do you have compression on # 1 if that is the cylinder that is miss firing??

Do you have a timing light with an inductive pickup on it,  if so you can clip that on the plug wire for the cylinder and see if the hole is firing.  If it is firing and has compression then it points to a fuel problem.  Eithe rin the form of no fuel available or no vacuum to get it delivered to the hole.  Someone gave suggestions for checking for a vacuum leak by supplying an alternate fuel in the form of carb cleaner - WD 40 will work as well or liquid fire if used prudently as excess potentially will break compression rings.

If you have compression, spark and no vacuum leak then you can start looking at the individual carb.

[art]

I do think the carbs are the problem I am going to rejet it an put a filter in the line.as far as pulling the carbs it is a snap ,about 1/2 hr an I can have all of them out at one time real easy.the biggest pain is the air box .A little wd 40 helps.I probably won't get it done for about another week but I will let you know what happens .thanks ,Art