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Old 11-20-2012, 08:46 PM   #71493
Gnarly Adventurer
Joined: Aug 2010
Location: Anchorage, Alaska
Oddometer: 189

Originally Posted by Jammin View Post
Need your advice, fellow DR riders:

As you may know, I was having electrical problems with my bike in western Tanzania (she's a 1998 with 74,000+ miles). She was dying after a few minutes of running and a reworked carb, a newer CDI, rectifier and ignition coil didn't solve the problem, so I figured it was the stator. I got a new stator shipped in, the 250W uprated one and installed that along with slightly-newer parts from parted DRs: a CDI from a 2006 and a rectifier from a 2001. After those parts, she fired up and sounded really good. I did 50 kms of test rides and was confident the problem was solved, so got back on the trail heading south.

But now, after 400 kms (250 miles), the problem is back. She died on me today in the middle of muddy roads. It felt like a loss of power. I let her cool, we rode a bit more and then she died again. I figured since I didn't replace the original ignition coil, maybe it was acting up now. I put in the coil from the 2001 bike and she died again in a few kms. Then I unplugged the generator and we ran for a while before same failure. Then I unplugged the rectifier and we ran fine for a few kms before she died again. The longer I let her cool down before trying again, the longer she lasts before dying again. To me, this sounds like something is heating up and causing the loss of power. It doesn't feel like a fuel (carb) issue. It feels like something is cutting power to the spark plugs. I limped her back to a small town.

I'm running on the Shorai battery and have a voltage monitor and after unplugging both stator and rectifier, battery was holding charge at 13.45 and after two starts with no stator, it dropped to 13.35 V.

I have a replacement wiring harness from the 2006 bike. Is mounting that on going to help? That's all I can think of now. I'm close to throwing in the towel and putting her on a truck and heading back to a good mechanic in Nairobi. Argghhh!!!!

I'm sure you have done this but I've been looking through the wiring diagram for you. Things that we know (or are pretty sure) are good:
CDI: You've tried 3 of them I think, including the original. They can't all be bad.
Regulator/Rectifier: You have tried a couple, with no change. Also, you tried with it unplugged with no change in bike's response.
Ignition Coil: You've tried 2 or 3 of them with no change. Again, they cannot all be bad. I would consider this an unlikely failure point.
Stator: You've replaced it with a brand new one, so both of it's coils should be fine.
Clutch Switch: The bike starts, so that shouldn't be a problem.
Battery: The bike starts fine, has good voltage, and the regulator is fine.
Plug Wires: I'm pretty sure you have replaced them.

When the problem occurs, do you notice any other electrical problems? such as flickering headlights? That could indicate corrosion or poor seating of the main fuse. I'd call this unlikely.

Check the ignition switch and its connector as well.

As far as the bike running, the current needs to get past the side stand safety switch and relay, neutral safety switch, and kill switch before it gets to the cdi. I expect that you bypassed the neutral safety switch and side stand switch when you initially prepped the bike? Maybe give them a quick check. I would also recommend checking the handlebar kill switch even though it is not heat related, it could be wet or dirty or corroded or something and be causing a shut down.

The CDI has 2 wires that end up going nowhere, 2 grounds, 1 power feed (depending on the safety switches), and 1 wire to the ignition coil. That should all be good.
It also has 2 wires coming from the source coil, which is wrapped on top of the charging coils on the stator. Since the stator is new, and the bike runs a bit, it is probably connected properly and fine.
The last two wires come from the ignitor/pickup coil. This would certainly be subjected to engine heat and have been known to fail. Have you replaced this? It's the little black box in the top of this picture.

So, in short from least likely to most likely: Main fuse, Safety switches, Ignition switch, Pickup Coil.
If the problem is indeed electrical (starting to have my doubts), and it's none of these, then it's gotta be a problem with the harness.
Feelers is offline   Reply With Quote