Cold Cylinder - Help

[ga_max]

I recently discovered that cylinder #1 (left rear) is not heating up at the same rate as the others. I've read other posts about this and decided to try and figure it out was is happening. The first thing I did was visually check that coil and wire and cap and they all look fine (I replaced the wires and caps last year). I pulled the plug and the cone was white and no sign of fouling but some gas was on the threads towards the bottom of the plug. I put the plug back in and started the bike without the cap on the plug and it started and ran like normal. As the bike was running I grabbed the cap to put it back on the plug and got a shock when my other hand touched the frame. Is that normal ? It wasn't a major jolt just a tingle. I'm wonder what my next steps should be ? I don't have a way to sync the carbs yet but am planning on getting a carbtune soon. Thank in advance.

Doug

 

[jfeagins]

What's your charging voltage @ idle ?

 

[Dragmaxster]

Yes the shock is normal - it might have been weak also.
Try screwing the plug wire into the cap a little further.
Also chech the coil wire by the battery- sometimes they come loose and need pushing in and then screwed on. There should be a little donut washer that goes around the wire and then screw it back on. The donut is sometimes left too short on the wire.

 

[ga_max]

Voltage at idle 13.6 volts (new RR last year make a big diff). Pulled the wire from the coil and it looks good, hole in the middle if the copper wires. pushed it in good and tightened. The donut washer is in place. Tighten the cap also. Still same issue. Does the white cone mean anything ? No sign of carbon on it. Actually look almost new.

 

[dannymax]

Voltage at idle 13.6 volts (new RR last year make a big diff). Pulled the wire from the coil and it looks good, hole in the middle if the copper wires. pushed it in good and tightened. The donut washer is in place. Tighten the cap also. Still same issue. Does the white cone mean anything ? No sign of carbon on it. Actually look almost new.

Sounds like it's running lean, may be a carb problem.

 

[Traumahawk]

Sounds like it's running lean, may be a carb problem.

I'm wondering if the idle circuit for that carb is plugged. Sounds like it's time for a shotgun.

Sent from my SCH-R890 using Tapatalk

 

[06VMAXIMUS]

Sounds like it's time for a shotgun.

Sent from my SCH-R890 using Tapatalk

double or single barrel? :biglaugh:

 

[ga_max]

That's what I was afraid of. Never played with the carbs before but I guess their is a first time of everything.

 

[wayne z]

You need to do more diagnosis, I would pull the plug wire and use a sparkplug in the wire boot, grounded to the frame or carb diaphram area, then crank the motor over and see if there is a good blue spark across the plug electrodes. if that's good , you need to verify compression on that cylinder.
To do a low tech compression test on mine I used about 6" of 1/2' cpvc (hot water) pipe with a cap on one end. Could use a rounded dowel or piece of broomstick ect. also. Just jam the end squarely centered and sealed against the plug hole and spin the motor. If it pops the pressure out rather smartly then you have compression.
Try it on a known good cylinder first to know how it should feel. If these tests pass, then suspect the carb next. if one carb is acting up and they haven't been cleaned real recently then all carbs prolly need cleaning.

Shotgun and peashooter methods will only help very slightly dirty carbs.

 

[Dragmaxster]

Voltage at idle 13.6 volts (new RR last year make a big diff). Pulled the wire from the coil and it looks good, hole in the middle if the copper wires. pushed it in good and tightened. The donut washer is in place. Tighten the cap also. Still same issue. Does the white cone mean anything ? No sign of carbon on it. Actually look almost new.

White cone is the insulator to keep the tip from getting too hot down low. You want to see them stay white. When you say HOLE in the middle it is always a good practice to trim a little off the end whenever you remove a wire for better connection.
I agree with traumahawk that you probably have some small jets in the jetblock clogged.

 

[Dragmaxster]

double or single barrel? :biglaugh:

Quad-:rofl_200:

 

[Traumahawk]

That's what I was afraid of. Never played with the carbs before but I guess their is a first time of everything.

Here is a link to the procedure

http://vmax.lvlhead.com/tips/shotgun.htm

If you run into issues, call or PM me. I'm not saying 100% that a plugged idle circuit is it.....but I would be 90% positive.

 

[ga_max]

Thanks all. I'll confirm spark tomorrow and get a picture of the plug posted. Danny is sending me a single carb from a venture (34 mm) to play with.

 

[fmcandrew]

Fuel, compression & spark is all that's needed. I had similar issue...after much screwing around I decided to install new CDI (Sean's advice)...problem solved...apparently CDIs can fail in all kinds of weird ways...