RX4 Charging Issue
 

Me again - new month, new RX4 issue...

Bike died on me again, leaving me stranded on side of the road for the 3rd time in less than a year. Just under 5,000 miles now. Electrical issue this time.

Poked around at the battery, the negative terminal was very corroded. Cleaned it up and jump start, wouldn't idle without dying. Bought a new battery, seemed to run okay. Ride into work today and the voltage started at 12 and steadily dropped until I arrived at around 9.6 volts (~45min commute). Surprised it go as far as it did...

Any tips on where I should start looking first?

Also, the tachometer has been intermittent for the last month or so. Sometimes it works normally, sometimes it displays wacky results, sometimes it shows nothing at all.

Thanks

sounds like your alternator is bad, it's not charging the battery.

I'm no expert, but wouldn't it be the Stator on a bike?

That was my thought, is the "alternator". Looks like that is a stator/rotor + rectifier on a motorcycle.

CSC said to check these items and replace as needed. Waiting for some clarification on how to test them. Service manual is pretty vague.

I've got it torn apart now and don't see any obvious mechanical failures. Connections look good.

Mostly posting on here to see if anybody else has been down this path and what the culprit was...

You should be seeing 14V with the engine running at about 3K rpm. Sounds like you are getting nothing from the charging system. After you check the connections to insure they are solid you are left with the components themselves.
The charging system only has a few parts...stator, rotor and R/R (regulator/rectifier). Of the three I'd guess the R/R to be the one to fail more often, particularly on a new or low mileage machine. In my experience with other brands (Ducati and Moto Guzzi) the R/R tended to over charge which led to battery failure. I think it's just a place where the manufacturer cut corners to safe a few bucks. In the past, when I had any doubt I just replaced the R/R with a MOSFET one. A Google search will give you all the reasons to upgrade and also suppliers. As I recall, I had to make connectors in order to plug into my wiring harness. The R/R is usually a sealed unit, thus nothing to tinker with.

Lots more information here: https://adventuremotorcycle.com/tech...ully%20charged.

Thanks for the tips. I tested the stator and it is not giving any resistance reading between the 3 phases, and outputs no voltage when running. Going to start by replacing the stator and rotor while its open. Or I will as soon as CSC has it back in stock. Might just get a new R/R while I'm at it and be done with it. Tired of messing with this.

Sounds like you have isolated the problem. That's a really odd failure. It would be interesting to learn what caused this.

Finally got around to digging into this further, I've had a new stator/magneto/rectifier sitting here for awhile and just put them on last night. Charging normal at around 14v idle like it is supposed to. See image for the culprit. The wire was disintegrated to the point that just brushing it with my finger broke it in half... any ideas on what could cause this at only 5,000 miles? Routine oil changes, with oil purchased from CSC. The engine got a little toasty there for a few trips when the thermostat broke. Seems like that wiring should be able to hold up to much more.

That looks brutal..... Was it hard to replace?
Glad the repair worked

Not overly difficult to get to the stator. Drain oil, remove a panel on the left side of the bike, disconnect the wires, disconnect the clutch cable. Then a handful of bolts holding the case on. 4 small bolts holding the stator onto the case.

The magneto on the other hand I did struggle with. You need a 28mm flywheel puller to get it off, and either an impact wrench or some way to lock the flywheel in place. I tried a bunch of wrong ways getting it off with no luck before breaking down and buying the tool...