earth wire

[Roblatt]

Hi all,

I've been experiencing a no start problem on my B11 where it only occurs on a cold morning if I leave the bike outside. I did the wiring mod as recommended here a few years ago and that fixed the odd non start. This time it only happens when cold and for the first start of the day, then it's good. I've had to jump start with a power pack on a recent trip I was on.

I've isolated the problem to the poor connection of the earth wire to the starter motor. I worked this out by leaving the bike out in the cold over night (after I washed it - not happy) to replicate the conditions.

As expected it didn't start. I checked all the usual relays and fuses and they were OK. I then connected a wire directly from the battery to the starter motor earth, and it fired up normally. So I'm going to clean all the contacts etc.

My question is, if I want to run another earth wire to the starter, is it safe to run directly from the battery negative to the earth on the starter itself?

thanks

Robert

 

[Kevin.NZ]

When you say"starter motor earth" do you mean the black/negative cable from the battery to the bolt on the bell housing/clutch cover? that has been known to cause issues if its not a clean connection, the same goes for the battery terminals. The starter motor itself is earthed by the 2 bolts that hold the starter in place, not by a separate cable. Make sure the spade terminal that operates the starter is a good connection too. Is the battery up to the task?

 

[john zibell]

Just remove the factory ground (earth) wire that Kevin mentioned and clean that connection. Even if it looks clean, a slight amount of corrosion will interrupt the ground path. This should be the first step in correcting electrical gremlins.

 

[Nordicnorm]

My B-11 (built in 2006) has two ground wires, one from the battery and one from the wiring harness. These were both grounded to a 6mm stud/sleeve nut combo (13mm head) that also holds the plastic cover for the starter motor. If you open the ring terminal from the harness to 8mm, you can ground it to the bell-housing bolt inside and slightly above the starter. You can tighten the heck out of it.
Then use the 6mm stud for the battery ground only. This will help the stud reach a little deeper into the threaded hole in the case for a more secure hold. The 13mm head is an invitation to overtighten the 6mm bolt. Be careful, or it is heli-coil time.

My last two startus-interruptus events before I did the MPH mod, taught me that if I wiggled this fitting with a wrench, the bike would start. So yes, it is quite sensitive to a poor ground connection here. That was 8 years ago. No issues since.

 

[Roblatt]

I have the same set up as Nordicnorm. I'm aware of all the ground wires that need cleaning as I've done them before. I'll try grounding to the bell housing. Out of curiosity, is it safe to run an earth direct from the battery to the starter where the 6mm bolt is?

thanks

Robert

 

[john zibell]

I have the same set up as Nordicnorm. I'm aware of all the ground wires that need cleaning as I've done them before. I'll try grounding to the bell housing. Out of curiosity, is it safe to run an earth direct from the battery to the starter where the 6mm bolt is?

thanks

Robert

No reason you can't. I'd recommend 10 gauge wire at a minimum and go to one of the 8mm mounting bolts.

 

[scott_m]

Just remember, contrary to popular belief (WHICH IS COMPLETELY WRONG) electricity does not take the shortest or least resistive pathway. Electrons take all available pathways, at the same time, every time, and in inverse proportion to the impedance in the circuit.

 

[Roblatt]

Thanks Gents. I have added the extra wire exactly as John suggested. While doing the work, I found the original earth wire is damaged - nicked by rubbing on the frame. I wonder if this caused the issue. Anyway, I've added the extra wire so hopefully now it should be good. Unfortunately/fortunately we're about to have a spate of warm nights so I will be unable to see if the extra wire helps for at least a few days.

Thanks again for every ones help, it is appreciated.

Robert

 

[john zibell]

Thanks Gents. I have added the extra wire exactly as John suggested. While doing the work, I found the original earth wire is damaged - nicked by rubbing on the frame. I wonder if this caused the issue. Anyway, I've added the extra wire so hopefully now it should be good. Unfortunately/fortunately we're about to have a spate of warm nights so I will be unable to see if the extra wire helps for at least a few days.

Thanks again for every ones help, it is appreciated.

Robert

Loss of insulation on a ground wire isn't an issue. For some vehicles the ground is a braided wire strap with no insulation.

 

[Brian UK]

The heavier gauge the wire, the better it works. Adding an extra one just adds to the overall cross section, so it will help. And as John said, use one of the 8mm bolts on the starter for best connection. That 6mm one holding the plastic cover has caused many problems for many owners.

 

[Roblatt]

Update.

I've had the chance to leave the bike outside for a couple of cold nights when the no start problem usually occurs. It has started perfectly each morning so it appears, thus far, that this fix has helped.

I also noted that other problems have disappeared. First, the revs no longer oscillate and second, when the bike was left in the sun, motor off, for periods of time, the tacho would creep up and I'd have to cycle the ignition a few times to get it back down. This no longer occurs. It may be just coincidence but.... a good earth wire, maybe fixes more than the obvious.

The tacho problem is a faulty stepper motor. I've had the problem for few years, the speedo was the same. I bought 2 steppers and changed the speedo stepper and left the tacho stepper until it fails completely as it wasn't a concern as I'd just cover it with by bandana when I had it in the sun.

cheers

Robert

 

[scott_m]

Nicely spotted! Well done.

Good info.