What makes symptoms like ignition coil pickup wire broken

[nezzer]

At the end of the riding season my bike developed some severe stuttering. Sometimes it is fine, then sometimes it stutters, barely accelerating at full throttle. Letting off the throttle, then reapplying typically fixes the issue for a little while.

This is EXACTLY the same symptoms I had when my ignition pick up wires were bad. I fixed that a few years ago using some flexible volt meter wiring. All was good until just recently.

I just got around to fixing the broken wiring. While trying to find the split I checked the resistance across the two sets of wires. I get around 600 ohms no matter how I twist and pull the pickup coil wires.

No I am not so sure the problem is pickup coil wiring.

Are there any other failures that would cause these same symptoms? The battery is brand new and fully charged. The coils and wires are all new this year. The symptoms started abruptly. One day it started hesitating and has continued to do so ever since.

[mack]

Fuel flow

When was the last time you checked the little screens on your fuel float needle valves?

[MaximPhil]

Wondering if a split vacuum hose would give these symptoms?
Phil

[DGXSER]

Coils

How new is new? What type of coils, brand are they? I have had some of the Mikes XS Coils go bad is under 5k miles.

[James England]

Could it be a blocked fuel cap vent?

[nezzer]

I installed Dyna DC1-1 coils about 2.5 months ago. I had green coils from Mikes XS, part number 17-6810, on there previously. The rubber coil boots wore out after 7k miles. I *think* one of the wires fell out of the coil while riding. The coil resistance was off so I replaced both coils and all spark plug wires with Dyna stuff

It has been two years since I stripped the carbs and ran them through the ultrasonic cleaner. I have had in line fuel filters in place the whole time though. They still look good.

One more piece of info. The last ride I did of the season was up into the rocky mountains, mostly highway. On the ride I noticed that as long as the throttle was on, I would never have any hesitation. The hesitation only occurred when applying throttle after idling. This leads me to believe it is not fuel related as I would have expected to have problems on those long stretches of high speed, not when I brake for a corner then reapply throttle.

The vacuum hose you are referring to is the one from the carb boot to the vacuum advance on the pickup coils? I haven't checked it for cracks. I will do that.

[bikerphil]

Check the primary wires at the coil connectors, I've had them appear to be OK but broken inside like the pickup coil wires. Give them a tug, if they stretch it's NG. My symptoms were hesatation mostly at lower speeds. GL

Edit: this would probably be more likely to happen if the coils have those bullet type connectors.

[TopCatGr58]

The vacuum hose you are referring to is the one from the carb boot to the vacuum advance on the pickup coils? I haven't checked it for cracks. I will do that.

Surprised Phil didn't see this! The vac. adv. hose is NOT to be connected to the carb INTAKE BOOT, but to the nipple on the #2 carb body itself. If you truly have it connected to the boot, you're getting too much advance too soon, etc.!

T.C.

[bikerphil]

I didn't see that TC, if it was me you were reffering to or Maximphil.

[MaximPhil]

I was wondering about a split hose. Connected to the wrong nipple would not be good either. Thanks TC for adding some clarity for nezzer to solve his problem.
Phil

[nezzer]

Connecting the vacuum advance hose to the carb intake boot... who would do such a silly thing. Jokes aside, my vacuum advance is connected correctly. I checked the hose and there are no splits. It is in good shape.

I checked the fuel filters just in case and they are both clear.

I did a resistance test on the wires running from the TCI module to the ignition coil. All 3 wires tested fine now matter how I twisted or pulled.

I did notice that one of the bullet connectors on the power lead for one of the coils was a little loose. I put some dielectric grease and clamped it down. I will give it a shot once the snow melts and see if that fixes it.