Kawasaki Concours Forum
The C10, aka Kawasaki Concours - The Original => The Bike - C10 => Topic started by: Drexmac on May 03, 2014, 07:48:42 AM
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My 88 Connie Lost a cylinder on the road recently. Still runs, but needs throttle assist to idle. I noticed difficulty with warm up a couple of days before. Smelled gasoline in exaust. Can see and smell unburnt fuel coming from exhaust. Found all plugs normal except #4, which was wet. Fuel is obviously being delivered. Visual spark test shows a pretty little blue spark. Any thoughts?
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Very common for the plug wire solid core to corrode, and burn off where the plug cap is screwed onto the wire. Grab the wire, and unscrew the cap from it. If the core looks corroded, trim about 1/2 inch of the end, jus snip it off, and screw the end back onto the wire. The center pin in the cap is actually threaded, and should thread into the core of the wire about 1/2 inch.
Report back.
The symtoms are what you reported, it will spark at idle, sporadically, but under load it will miss. Common.
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Does the bike run ok when riding and misses at idle?
If so, Sounds to me like 1 carb may have a stuck float (or trash under the needle).
Ride safe, Ted
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I will give the wire trim a shot. Ted, it always runs poorly now. Thanks!
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Replace the plug , and do what MOB says. Most of the time the plug will not come back to life even if you see a nice blue spark. Check the fuel levels with clear tygone tubing to eliminate carb bowl fuel level issues.
My bet is you do not have overflow tubes and if so you may have a stuck open float needle valve.
If you have a stuck open float valve (and no overflow tubes) you maybe flirting with damaging/ruining your engine. Do a search on Hydrolock..
Dont try and start it until you verified the floats needle(s) are working. Look for dirt / debris after draining the bowl(s) into clear clean glass.
Please say 'Yes, I have overflow tubes' .
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If, after replacing the plug and trimming the wire the cylinder still won't fire, I have done something that has worked each time I had similar symptoms. With engine off and bike on center stand, I put a piece of tubing on the fuel drain of the carb float bowl that is long enough to reach a clean quart glass jar sitting on the ground. I open the drain for the carb on the affected cylinder and drain it. It should drain about an 1/8 of a cup and stop (leave the drain open if it stops). If it continues to drain, you have a bad fuel petcock and that will need to be replaced as well. After draining the carb, and verifying you do not have a hydro-lock (which you shouldn't if the initial carb drain stopped) start the bike and keep it running. Gas should start to flow into the glass jar. After about 30 seconds shut the engine off and close the drain. Restart the engine and see if the cylinder picks back up. You may have to rev the engine a couple off times but usually it clears up pretty quickly. Also, you may have to repeat this a couple of times. The reason for doing this is to attempt to flush any debris that might be stuck between the float needle and the seat. By draining the carb first, you are dropping the float as far down as it will go, thus moving the needle as far away from the seat as possible. Usually (for me at least) the fuel will flush the offending trash out and into the glass jar, and the the needle will be able to do its job again. IF, this does not work, MY next step would be to do a compression check on that cylinder to make sure it is mechanically sound and capable of producing enough compression to support combustion. HTH
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Well that is close. Let me help.
You want to check for:
Is the float needle opening? (in your case yes because your spark plug was wet)
Is the float needle shutting off? Probably not which is the most common problem.
Is the float needle shutting off at the proper height? use the clear hose and hold it against the carb where the dividing line is where the bowl meets the carb. With the petcock turned to Prime (fuel flowing and drain valve open) and your lowering the hose, the float valve should open, fill the hose to the line and stop.Keep lowering the hose... you may need a longer hose.... does the float stop the fuel at the line?
I now believe you do not have overflow tubes. You would already know the answer to the above if you did.
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I checked the wires. All appear ok, don't see any discoloration or such. I'm thinking about converting to the coil sticks.
I don't believe that I have overflow tubes. Can't seem to find any info that shows a pic or diagram. I'll keep looking, but if anyone could tell me what to look for, then I'll have a better idea if I have them or not.
I noticed that the #4 bowl drains more fuel (125 ml) compared to the #1 bowl (75 ml)...every time I drain it. With plugs out, Fuel sprays from the cylinder for at least 5 compression strokes...(hydrolock waiting to happen).
After I drain the cylinder of fuel, and drain the bowl, it cranks and runs smoothly for a few seconds, then back to 3 cylinders.
I'm starting to suspect the float, or needle...just as suggested. Any new thoughts?
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Time to send the carbs here before you break the engine.
https://sites.google.com/site/shoodabenengineering/
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I don't believe that I have overflow tubes. Can't seem to find any info that shows a pic or diagram. I'll keep looking, but if anyone could tell me what to look for, then I'll have a better idea if I have them or not.
Stick a piece of hose on the bowl drai nipple and blow into it with the drain screw shut. Iff'n you can blow in, you have overflows, if not, not.
Good Luck.
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IMO, the float bowls will drain out different amounts because there is one common fuel supply/tubes which feeds all the carbs.
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With plugs out, Fuel sprays from the cylinder for at least 5 compression strokes...(hydrolock waiting to happen).
After I drain the cylinder of fuel, and drain the bowl, it cranks and runs smoothly for a few seconds, then back to 3 cylinders.
I'm starting to suspect the float, or needle...just as suggested.
Definitely a carb is flooding from : trash on seat of stuck needle.
Stop cranking before you get hydrolock!
Ride safe, Ted
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oh boy, you gonna hydro-lock (destroy) that engine soon if not already. Remove the carbs and ship them out for repairs.
Please !!! :battle:
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hydro lock test shows I'm good! Carbs sent to shoodaben are on the way back, along with an exhaust cam sprocket. Thanks Steve!
I just received my stick coils. Thanks T Cro!
Hope this more than fixes the problem.
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It's going to run like a new bike!
Ride safe, Ted