Right cylinder isn't firing properly

[nealwp]

 :huh:I went to go for a ride this evening and started the 2000 Bassa up and went a short distance and suddenly it wasn't firing on both cylinders properly. I returned home and sure enough the plug from the right jug was wet. The left side is nice and chocolate brown. I hooked the plug wire up to the plug and watched it as I ran the engine. I'm getting sporadic spark but it isn't consistent.

I suspect it's the plug wire. Does this seem reasonable?

Should I start by replacing the wire and moving back from there?

Could it be the coil?

What else could it be? up to this point it's run beautifully.

[pehayes]

Guzzi did a bad job routing the spark secondary wires on this vintage.  Follow the spark secondary wire from the coil to the right side spark plug.  Likely you will find it jammed between two cylinder fins at the base of the right cylinder and there will be substantial chaffing to the wire.  Hence intermittent spark leakage.    Cover the wire in some protective wrap temporarily to solve the issue and eventually replace the spark wire.

What are you using for plugs? and how old?  My preference = http://www.guzzipower.com/Sparkplug-pehayes.html

Patrick Hayes
Fremont CA

[Tom]

Thanks for the info on the plugs.   

[nealwp]

It was a chafed wire from my Power Commander III. I removed it and my bike fired properly instantly. I'm fairly sure I got it. I have ordered a plug wire kit from MG cycle. They have never been replaced. Coils really don't fail much in my experience and when they do they don't cause the type of failure I experienced.

I'll stick with my computer with out the PCIII USB. I don't know that it was doing much anyway. It was so bulky that the wires were pinched. I have a really good diagnostics tool from another vendor.

[nealwp]

Maybe I should re-think my PCIII as the root cause. It doesn't seem right that the computer would affect only one side.

[Tom]

The Digiplex, Motoplat oem ignitions and aftermarket Dyna ignitions will only work one cylinder when dying.  Sometimes the easy fix is to retrofit a distributor and points ignition.

[nealwp]

It has the Magneti Morelli ignition system. Do they behave the same way?

[normzone]

Well, whatever root cause you arrive at, please update this thread.

As the owner of a '99 Bassa, I bookmark ALL these things against the day when ...

Thanks -

[Tom]

It has the Magneti Morelli ignition system. Do they behave the same way?

Have no experience with your style ignition system.  Someone else will have to comment.

[nealwp]

I have plug wires and caps ordered. I reinstalled the Power Commander and it is running like a charm. There is some wear on the insulation for the plug wire.

I'm perplexed. It has never happened before. I suppose the cause could be any number of things. I suspect wiring.

[Tom]

It's probably because the spark plug wire were old and needed replacing.  Checking the bike at night while it's running is a good way to find out or a spark plug wire tool.

[John A]

I had this same problem on my Bassa long time back.  Turns out that the hamfisted clown (me) had dislodged the power wire to the coil at the fuel filter change so it was making intermittant contact.

[nealwp]

 Well I have learned one thing from this. My Power Commader does improve performance. I noticed the improvement when I re-installed it. I'm still scratching my head over the cylinder. I might have fixed it by simply reinserting the wire to the coil. It could also be that I fixed a connection when I opened the side panel to check check my computer out. At this point I'm chasing a ghost.

[Tom]

PC III Commander is an add-on that helps with your ignition system.  Sounds like you cured the problem of a loose connection and/or bad plug wires.  At this point....leave it alone and ride.