Miss on one cylinder??

[maxed141]

Finally got the vmax out for the first time.... Ran great, but started to develop a slight miss about hour into it. I didnt think much about it but went to start it the next day and it was missing real bad!
Checked fire on the left side front and no spark! Checked it again with a new plug and still nothing... All the other cylinders have spark! Could the cdi kill just one cylinder???

 

[maxed141]

It's a 1985 too BTW...

 

[Fire-medic]

Well do the basics on that thing before leaping to the diagnosis of a bad CDI box, but yes, that could be it.

If I were you, I would try to see if you could rig another coil in-place of the one you suspect, since the front coils are such a pisser to remove (to switch them side-to-side, to see if the dead plug follows the coil being switched).

Try removing the spark plug cap and trimming-back about 1/2" from the high-tension lead going into the cap. If you see a lot of green corrosion typically on the wire end when you remove the cap and wire, you may luck-out and have the trim-job solve your problem for zero $.

After that, look at the wire connections into the coil, checking for frayed wires, or broken strands where the terminal is.

 

[maxed141]

Checked all of those first... Swapped coil with no luck. Had a new set of COPs tried that one on that cylinder too, it's dead!
Didn't know if a CDI would do that or so I need to look elsewhere

 

[Fire-medic]

Checked all of those first... Swapped coil with no luck. Had a new set of COPs tried that one on that cylinder too, it's dead!
Didn't know if a CDI would do that or so I need to look elsewhere

The CDI is the 'distributor' on our bikes, so you could have one bad channel. "Replace the suspect unit w/one of known good operational qualities."

 

[jethrobolas]

Or it could be a carb issue.

 

[Constantinos]

Or it could be a carb issue.

In what way is this a carb issue since there is no spark?

 

[sdt354]

Swap that TCI with a known good one. If the coil wiring is ok, and considering the checks done. It's a good chance the TCI is bad.

 

[sdt354]

PM sent.

 

[maxed141]

Thanks for all the input guys... Would it be best just to upgrade to a dyna or similar ignition?

 

[alorio1]

If you do an upgrade, I would suggest this one; http://www.vmaxforum.net/showthread.php?t=23506

That TCI has so many options it would be hard for me to choose a Dyna over this one....Check with Sean Morley, I think he keeps them on hand; [email protected]

 

[fmcandrew]

I picked the new Dyna (software switchable) over the above one for simplicity's sake. Pull out the old one, plug in the new one and your off & running. It has plenty of features, but if you're going to blow or juice it or like the option of controlling your vboost then the above option is better suited...I'm sure others with far more knowledge in this area will chime in as well...

 

[m-cman]

Used stock ones have gotten pretty cheap on eBay.

 

[jethrobolas]

In what way is this a carb issue since there is no spark?

Guess I didn't read the first post very well.