Running / Idling on 3 cylinders?

To start, it's an '81 XJ650 Maxim with 14,xxx miles.
It had a leak in between the # 2 & 3 carbs, which was the o-ring.
When all was re-installed it seemed to be idling lower than normal.
Pulled the # 4 plug wire and no rpm cahnge.
Checked fuel level, compression, vacuum, and spark, all are good.
When removing the vacuum nipple cover the rpm jumped for a second.
Used a cap off of a spray can as a resevoir and a nozzle tube off a WD-40 can, used like an external venturi.
RPM increases to the proper level.
With help from neighbor, pulled plug while doing this and RPM drops.
This appeared to me as a fuel problem to me.
Pulled the carbs back off and checked all passages, all clear.
DOES ANYONE HAVE A SUGGESTION / IDEA? :idea:
IT IS DRIVING ME CRAAAAZZZY!!!!! 8O
HELP!!!!! :?:

 

Additional information, thought that the intake boots might be leaking so I poured some gas over the boots and nothing happened.
The plugs appear to have a slight white grey color on #'s 1,2 & 3. # 4 is slighlty dark.

 

Let me see if I have this straight ... ???

You POURED gas on the Motorcycle ... !!! Damn ... !!!

I'm sure that when everyone else is able to compose themselves ... you'll get a few responses regarding tune-up and initiating carb work.

Since this is the first time in my 58-years that I have ever heard of someone deliberately pouring gasoline on a motorcycle ... I'm going to need some time to compose myself, too!

In the mean time ... before you do anything else ... I think it would be a good idea if you program -- 9-1-1 -- into your speed-dial.

The image of you pouring gasoline on your motorcycle is ridiculously funny!
The fact that you might have killed yourself, others or wound-up in a burn ward having the next six months worth of meals fed to you through a narrow plastic tube run-down through your nose -- is absolutely frightening!

 

lol

 

The engine was cold, and it was only enough ( a small cap full ) to see if the intake boots were cracked through & through and leaking vacuum.

I did not pour a bucket gas over a hot engine.

I'M NOT STUPID!!! :!: :evil: :!:

Also, whenever working on engines, I have a fire extinguisher closely available.

Now does any one have any helpful ideas?

 

I am that stupid.I would do it with a lite cig inmy mouth thou.lol.Think I heard you are suppose to use wd40 thou to see if boots leak or bubble.Wd40 is also flammable I do beleive.

 

OK now that were composed.

Did you pull the diaphram covers off of you carbs (specificly #4)
If you did and you now have a vacuum leak in that diaphram seal, that could cause a slide not to open and not get enough combustion air to that cylinder. (you shouldnt have to pull carbs to fix that?!)

Next time your engine's cold and you 1st start it lightly and quickly feel of the exhaust pipe and see if it heats up at the same rate as the other pipes/cylinders. If not then that cylinder is not having proper combustion.

Check spark by grounding the plug to engine with spark plug cable hooked to the plug and start engine (should have a blue spark) dont run engine more than a second or two.

Let us know what you find with these checks.

 

ya get that sorted out yet? navyjuice

 

I had a very similar problem on mine. It turned out to be a bad battery!

Your alternator doesn't provide enough voltage to get a strong spark at idle, so the battery has to pick up the load, and if the battery is bad, some of the alternator power is continuously being drained charging the battery.

So, on a motorcycle, you may notice running problems before the bike is hard to start! This is quite different than a car.

Mine was running on 3 cyl too with the bad battery, so I betcha a dollar that is your problem! With the new battery, it immediately went away.

 

I had this happen and it was an air leaks in the boots. tried soapy water first but never saw anything bubbling up, but since the boots were all dried and cracked, I patched them up anyway with cut up intertube as a test.

 

Gasoline would definitely be the absolutely last thing I would use to hunt for a vaccum leak. Navyjuice, I'm with Rick here but before you get sore, I understand you did use some common sense when you did it. I'm certain no one here thinks your an idiot. A fire extinguisher is another measure of your competence, so you can't be stupid. Now Rich has an interesting thought, I would not have thought to look in that direction. Bean, yes WD will support combustion but the wise fellow doesn't smoke while working near combustubles, they tend to set themselves on fire. And I would hate to hear of anyone having experienced that, I've seen the results and I wish I hadn't. Gastly. Please refrain from such practices, we'd like to keep you around. Hope you nail it Juice, I'm curious to hear what you find.

 

Thanks, finally broke down and took the suspect carb down to parade rest and bathed it in carb cleaner solution. Put it back together, eyeball sync, and back on bike. Need to do a little fine tuning, but the suspect cylinder now seems to be stronger than the other three. Again, thanks.

 

Way 2 go Navy I'm glad your in the wind again.
I'd follow up with a sync and carb adj. even if you have to go to a shop.
Hopefully you know someone with the tools.

 

He does, I'm just to darn far away!

 

I got em too, but I'm too far away too.

 

Good to see nav , a compression test would confirm alls ok too...