Intermittent engine cut off

[Black wing]

so first off the symptoms,

 

-when the bike is at idle voltage reads at 12v with no accessories on

-battery voltage after being off for several hours is 12.75V

-if i leave the bike idle for a while it becomes very choppy when i go to leave and the RPM's will occasionally just drop down to 0 and jump back up while riding.

-voltage on the gauge reads 14 v when driving

 

 

im almost thinking the kill switch is goofing off or the stator is letting go

[frankd]

If you're wondering about the kill switch causing problems, turn you cruise control switch and look at the left light next time it sputters. If the light is on @ normal brightness, your kill switch is fine.

 

You tach going to zero kind of points to the ignition module or the pickup coil going bad. Also the connector for the pickup coil is just above the back of the engine on the left side and Dingy says he's seen some of them causing problems because they're dirty. To clean my connectors, I use contact cleaner (available from an electronics parts place--Radio Shack used to carry it, but don't know if they still do), and then blow them out with air and coat the contacts with di-electric grease. Some have removed their ignition modules and dried them out in the oven.

 

 

Frank

[Flyinfool]

There is good news and bad news here.

The good news is that you have all but eliminated carb issues as the culprit.

The bad news is that it is an intermittent electrical issue. The worst thing to find. There are a lot of electrical things that can cause your symptoms.

 

The big clue here is that the tach drops to zero when the engine stumbles. This means that there is no longer a signal being sent to the #2 coil. If it was just the #2 cylinder dropping out you would hardly notice it at all in the running. This means that you have multiple cylinders dropping at the same time.

 

As Frank mentioned the cruise is a indicator of power to the ignition. If the "ON" light flickers dims or goes out while the engine is stumbling then you know that that circuit is the problem.

 

I would start by checking all of the power and grounds to the ignition system and clean the kill switch. They are the easiest things to do.

[GeorgeS]

If you still have the " stock " fuse block, be sure to check the fuse holder tangs, for the " Ignition Fuse " This is a common trouble spot.

 

Deffinatly, open up and clean the Kill switch with contact cleaner.

 

Also, check the Large white plug between the stator, and the voltage regulator.

Check for burnt pins, in this plug. This is Very Common, on 1st gen models.

 

And, of course, double check your battery post connections !!!

 

Also, you should pull both plugs out of the TCI, and Clean the contacts.

 

Might also, be dirty contacts, in the ON/OFF contacts of the ignition switch, however this is not usually a problem on 1st gens, ( only 2nd gens , which is very common )

 

Find the Barrometric pressure sensor, Fwd, and Above the left front carb. pull the rubber boot off the plug, and check for water, and crud, in the rubber boot.

Clean the contacts on that plug. Its hooked to the voltage, from the Igniton Fuse.

That plug, can effect ignition !

[MasterGuns]

Do you have the stock TCI or have you installed an Ignitec unit?

[Black wing]

ok tci is an upgrade form dingy

carbs were synced 2 weeks ago runs super smooth between hickups

stator connector has been removed and soldered

will check pickup and kill switch tonight

[Neil86]

When the bike is warm, probably testing the pickup coils and checking the connector from pickup coils is a good plan.

Edited September 9, 2014 by Neil86

[MasterGuns]

I think your "dropouts" are related to the ignited tci.

[icebrrg3rd]

...when the bike is at idle voltage reads at 12v with no accessories on...

 

 

What is your idle speed/RPM? I know mine will drop to about 12v if I idle too long (no acc. on), but shoots back up to around 14v once I'm cruising, starts to climb if I hold it just above idle too. Mine idles around 950 RPMs.

 

...the RPM's will occasionally just drop down to 0 and jump back up while riding.

 

...tci is an upgrade from dingy...

 

Mine does that too, which one did you get from him, the V88 one?

 

Also, is it just a momentary cutout while riding & it goes right back on OR does it completely cutout and leave you dead on the road?

 

Also, I was having some electrical gremlins, I replaced the old tube fuses with blade ones and haven't seen them lately (knock on wood).

 

-Andrew

[Black wing]

just momentary, just cuts out for a sec then hits me in the butt and takes off again

[dingy]

I think your "dropouts" are related to the ignited tci.

His TCI is well after group that had issue. It would not be first thing that would concern me. Pick up coils should be checked warm and complete circuit back to TCI for pickups.

 

I have had several buyers of Ignitech TCI's that still had a no start with new TCI and it was traced back to pickup circuits. Last guy was in Thailand with a VMax about 3 months ago.

 

Gary

[Black wing]

how can i test for a failing pick up? i cleaned up a few bad fuses and connections and is running better but still intermittent. i can have hours between hick ups and is not really showing symptoms past those points.

[Neil86]

You mentioned if it idles for awhile it triggers the stumble.

You might repeat this condition and do a couple tests...

 

While the engine is running during stumble, test the power into the

Igniter (Red/white) on the bike 8 wire connector. Test it versus the black on that 8 wire connector, to

make sure power supply is steady.

 

Then shut off bike and unplug the 6 wire connector and test resistance down to the 4 pickup coils

(orange-Black, Gray-Black, White/Green-Black, White/Red-Black etc) looking for uniform resistance.

Using the black on the 6 wire connector.

Edited September 12, 2014 by Neil86