Won't run when wet, Dies when put in gear - Solution

[Barnfresh]

This is a solution to the stall problem when put into gear after washing the bike. It may also cure other ignition gremlins that can cause one or both ignition coils to stop firing after driving in the rain or possible failure when dry. This solution comes from a friend of mine who has owned his 79F since new and takes meticulous care. When the ignition failed after he washed his bike, this was his findings:

There is a connector under the fuse block mounting plate that has the four low-voltage ignition sensor wires and the one 12 volt light blue wire (Sb on the Chilton wire diagram). This connector is for the wires that run to the lower left side of engine – Pickup coil wires and the neutral indicator light. The connector gathers dust and road salts in it and when water enters, the voltage on the blue wire is shunted into the low voltage circuit disrupting one or both sensor signals and dropping out either half or all the ignition. When the neutral switch is closed, the voltage on the blue wire is at ground and causes very little interference with the sensors although I did note some. With the neutral switch open, the N light goes off, indicating the bike is in gear, the voltage on the blue wire goes to 12 volts and the sensor signals are completely disrupted.

I disconnected the connector and cleaned out the sand/salt, washed the connector with water, blew it dry with air and reconnected. That in itself solved the issue but I think having 12-volts in the vicinity of the sensor connectors is problematic.

As my picture shows, I disconnected the blue wire from the connector entirely and routed around the sensor connector (yellow jumper wire). I have a feeling that the 12 volts entering the ignition module is not good under any circumstances so why risk blowing the module or sensor.

You know, disconnecting and cleaning connectors every 10 years or so is probably a good idea anyway. Removing the salts that accumulate will help extend their lives. In this case, 12 volts sharing the same connector as the low voltage (+- 5 volts), this plug is even more susceptible to voltage leakage upsetting the signals to the TCI.

[bikerphil]

I've had this problem, bike dies when dropped into gear when wet. I removed the sky blue wire from the neutral switch under the bike and grounded it under the nearest shifter cover bolt. Neutral light stays on but bike runs on all 4.

[Barnfresh]

Phil - Bet if you clean this connector and jumper around it, then you can hook your neutral light back up - good as new! I think this is the weakest link in the primary ignition circuit. We were able to put a teaspoon of water on that plug and recreate the problem before the jumper wire was added. Now - bring on the rain!

[ManagerMike]

Great info! I'll make that correction before I go home today.

[Barnfresh]

The PO had grounded the neutral light on my bike also - I never could figure out why. It seems like grounding the neutral light is a common work-around to keep the bike running when wet. I hope this fix cures that and some other primary ignition ills by isolating those low voltage wires to the TCI.

[skids]

This is a solution to the stall problem when put into gear after washing the bike. It may also cure other ignition gremlins that can cause one or both ignition coils to stop firing after driving in the rain or possible failure when dry. This solution comes from a friend of mine who has owned his 79F since new and takes meticulous care. When the ignition failed after he washed his bike, this was his findings:

There is a connector under the fuse block mounting plate that has the four low-voltage ignition sensor wires and the one 12 volt light blue wire (Sb on the Chilton wire diagram). This connector is for the wires that run to the lower left side of engine – Pickup coil wires and the neutral indicator light. The connector gathers dust and road salts in it and when water enters, the voltage on the blue wire is shunted into the low voltage circuit disrupting one or both sensor signals and dropping out either half or all the ignition. When the neutral switch is closed, the voltage on the blue wire is at ground and causes very little interference with the sensors although I did note some. With the neutral switch open, the N light goes off, indicating the bike is in gear, the voltage on the blue wire goes to 12 volts and the sensor signals are completely disrupted.

I disconnected the connector and cleaned out the sand/salt, washed the connector with water, blew it dry with air and reconnected. That in itself solved the issue but I think having 12-volts in the vicinity of the sensor connectors is problematic.

As my picture shows, I disconnected the blue wire from the connector entirely and routed around the sensor connector (yellow jumper wire). I have a feeling that the 12 volts entering the ignition module is not good under any circumstances so why risk blowing the module or sensor.

You know, disconnecting and cleaning connectors every 10 years or so is probably a good idea anyway. Removing the salts that accumulate will help extend their lives. In this case, 12 volts sharing the same connector as the low voltage (+- 5 volts), this plug is even more susceptible to voltage leakage upsetting the signals to the TCI.

OK, rode the bike to the nearest carwash (12 miles) and had issues all the way home. It is no damn fun riding these bikes in the rain either. Neutral, no missing. In gear, two cylinders. I am going to do this modification that Barnfresh discovered on all three of my standards!

[TomB]

I had the same problem in (not so) sunny England. Cough splutter when riding, runs perfectly with neutral light on.

I rewired the two circuits separately. I renewed the pick-up coil wires with sheathed wires from inside the left cover with no joins right up to the block connector under the right side panel. And a new neutral light wire.

Ride all day in torrential rain now with no problems

[skids]

Yes, I think Crazy Steve had it right all along (never doubted him). I have not confirmed yet that Barnfresh's mod will be the end-all but I sure as hell hope so!

[Schming]

Hope you guys don't mind some pics of this mod
The following is just what I did after reading multiple threads on this problem area. Kudos to those who trouble shooted this annoyance.

This is the plug/connector, behind the fuse panel that is behind the right side cover, that houses the pickup coil & neutral wires, notice the Sky Blue neutral wire:


As stated, remove the neutral wire from the plugs by inserting a small flat blade screwdriver to release the tang on the wire connector (This pic shows how to insert the screwdriver only, the neutral wire was already removed from the middle of the plug):




I removed the, SB neutral wire from the lower harness and found a test lead wire and spark plug cap to replace it:



Used vacuum hose as an insulator/ protector:



Fastened to N switch and spark plug cap fits snugly:



Crimped proper spade terminal on, up top:



Used marine heat shrink to insulate and waterproof:



The preceding removes the possibility of a shunt from the neutral wire to the pickup coil wires when wet from washing or rain.

I replaced the 30yr. old, cracked, hard, insulator/ protector sheath on the pickup coil wires also:


Marked the plug then removed the wires:



Using what I had in the shop (see cheap) I pulled the wires out of a proper length 12/3WG romex house wire to use the outer casing for the replacement:



A little blurry but I pulled the wires through with a piece of .035" MIG wire (again, use what ya got):



I siliconed a spark plug cap on the top part of the harness to waterproof:



I used a shifter rubber piece to insulate/ protect/ waterproof the lower end:


And completely Insu-Isolated & Waterproof





Thanxs 4 watching

[BA80]

If y'all just unplug the pick up coil wire plug behind the fuse panel, which also has the neutral wire plug, and fill it with dielectric grease so that it squishes out when you plug it back up it should solve your wet running issues.

The plug gets water in it and shorts out. The dielectric grease keeps the water out.

[Schming]

Yep Greg, did that too, to every connection on the bike

So I is gooder than good

[TomB]

If y'all just unplug the pick up coil wire plug behind the fuse panel, which also has the neutral wire plug, and fill it with dielectric grease so that it squishes out when you plug it back up it should solve your wet running issues.

The plug gets water in it and shorts out. The dielectric grease keeps the water out.

Well er, not in my case, water in the plug wasn't the issue, it was getting in somewhere in the sub loom that the pick-ups and neutral light shares down near the neutral light switch. I tried the dialectric in the plug, then tried removing the wire connector from the plug as John has shown in his pics to rule out it shorting across but still no joy. Only a completely separate new set of wires spliced in and placed inside the cover so the join is kept dry, and no more joins until it reached the connector block sorted it. Of course try the dialectric first, it may be just that on other bikes, as Greg found.

As Skids says, took mine to the car wash and it wouldn't run afterwards unless in neutral, so I left it sat for 5 mins ticking over until the engine was real HOT which dried it out, then it would run Ok when in gear.

[BA80]

Yeah, I've seen that too but not often. As I said SHOULD take care of it.

[Schming]

Yeah, I've seen that too but not often. As I said SHOULD take care of it.

LOOK ^^^^ UP !!!

There's 5 of us XSers that had the problem just in this thread.

[BA80]

LOOK ^^^^ UP !!!

There's 5 of us XSers that had the problem just in this thread.

Yes Schming , I am aware of what was posted. Overkill isn't always the answer though.