74 850 left me stranded

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We all know, owning a Norton is a Love / Hate relationship.
You'll get it, and then fall in love again......
 
maylar said:
Need to test the gas tank vent. It's about the only unknown remaining. ~SOMETHING~ is up with the fuel.
Click to expand...

baz said:
Disconnect one of the fuel tap pipes and run into a container
With the fuel tank cap on open the petcock
You should see a constant stream of fuel going into the container,not slowing or stopping
Click to expand...

A similar test with the cap closed will see the stream slow if the vent is blocked.
 
concours said:
This is GOOD. A hard short. Inspect the wiring relevant to the RR. Then prepare to replace the device. FLA, AGM bat, not LiFe, correct?
Sorry about the rain.
Click to expand...
So, I went out to the garage yesterday with my trusty Fluke to have a look-see. Without touching anything else I measured the resistance of the regulator wire to ground, expecting to find a dead short. Nope. High resistance, that behaved like a capacitor charging (low resistance at first, increasing to infinity within a few seconds). Connected that wire back to the harness and the fuse didn't blow. I put an ammeter in the battery line and it read about 1/4 amp static and 2.5 amps with LED lights. Started the engine -- all was normal. Ammeter showed charge direction at 1200-1300 RPM as usual. Went for a 10 mile ride with no issues (first stop was the auto parts store for more fuses).

That wire goes directly from the battery harness (ignition switch) and the R/R, nowhere else. Wiring is well insulated and supported. My only conclusion is that something inside the Shindegen is shorting to ground when it gets hot. It can't be a solid state device failing, because the regulator still works.

A new R/R is on order.
 
Tornado said:
Curious when you said cap not getting fuel on it....it will with each and every slosh about from below with more than say 1/2 a tank full. Carb spray squirt into the cap vent hole should clear it up....maybe follow with a wire poke or two for good measure.
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Anybody know what size the vent hole should be? I'm considering running a drill bit through it (there is rust there).
 
maylar said:
Anybody know what size the vent hole should be? I'm considering running a drill bit through it (there is rust there).
Click to expand...
Sorry if I'm stating the obvious, but there are vent holes on the top plate and bottom plate but they don't align, so any probe from either side will meet with obstruction.
If fuel flows freely when the cap is closed it must be functioning okay, IMHO....
 
maylar said:
So, I went out to the garage yesterday with my trusty Fluke to have a look-see. Without touching anything else I measured the resistance of the regulator wire to ground, expecting to find a dead short. Nope. High resistance, that behaved like a capacitor charging (low resistance at first, increasing to infinity within a few seconds). Connected that wire back to the harness and the fuse didn't blow. I put an ammeter in the battery line and it read about 1/4 amp static and 2.5 amps with LED lights. Started the engine -- all was normal. Ammeter showed charge direction at 1200-1300 RPM as usual. Went for a 10 mile ride with no issues (first stop was the auto parts store for more fuses).

That wire goes directly from the battery harness (ignition switch) and the R/R, nowhere else. Wiring is well insulated and supported. My only conclusion is that something inside the Shindegen is shorting to ground when it gets hot. It can't be a solid state device failing, because the regulator still works.

A new R/R is on order.
Click to expand...
Are you replacing your R/R with another Shindengen unit? Or something else?
 
Derek Wilson said:
Are you replacing your R/R with another Shindengen unit? Or something else?
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Yes, another Shindengen. One thing I love about them is the weather tight connectors that they use. Much easier to deal with than the individual wires of other designs. Besides, they're rated for 35 amps and no other brand is. I'm considering this to be a non-typical failure and don't expect to see it again.

Lets hope that the gremlins agree with that assessment.
 
There are many sub standard fake Shindengen’s out there I’ve been told.

Are you / did you buy from a trusted source ?
 
"Shorai LiFePO4 battery"

Just noting, that I have low confidence in this type of battery technology, and a failing battery could be the culprit. Not wanting to derail the thread, start a flame festival, or call anyone's baby ugly, just my views. They save weight.​
 
concours said:
"Shorai LiFePO4 battery"

Just noting, that I have low confidence in this type of battery technology, and a failing battery could be the culprit. Not wanting to derail the thread, start a flame festival, or call anyone's baby ugly, just my views. They save weight.​
Click to expand...
I don't share your distrust. The battery blew 20 amp fuses multiple times while troubleshooting, and ultimately got me home (3 miles) without a charger attached. Next morning it was still 13.3 volts and e-started the bike without complaint. I like them.
 
Hopefully this is my final update here.
Replaced the Shindengen and it seems to be working fine. I have a charge warning light, but I'll also put my volt meter back on today.
BTW, for those in the US this guy sells the real deal SHINDENGEN MOSFET FH020AA

My gas tank cap vent did look clogged with rust, and I poked it clean. A rebuild kit is on the list for this winter.

Went for a 30 mile ride and the bike was flawless. Unfortunately the rain made it ugly which will take a few hours to correct. But not today, it'll be 70° and sunny and I want to RIDE.
 
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