81-550T, R/R tested good, but?

[Buffalo Bill]

Thanks, that's useful?

Thanks, that's useful?

The Hanging idle concept could be correct, because as a reaction I can unscrew the fast idle screw until it reaches an exact point, then it just plummets down from 2200 and dies. This only happens after the engine is completely warmed up by riding.
I was suspecting things like the base of the vacuum tube for the petcock on the #2 carb. The valve ends could be letting air in too.
Thanks. Bill
P.S. I think this was my 1000-th post!

 

[tom203]

Your first post said that idle was ok with headlight off- which implied an electrical problem; maybe bad connection in headlight circuit or a r/r that doesn't deliver at low rpms dropping system voltage. That stator loop to left hand switch is useless IF you run with your headlight on- you're better off just sending stator output to r/r. But the r/r has to be working at 1500 rpm as well as 4000. A faulty r/r could deliver 15 volts at 4k thanks to higher frequency, but fall way off at low rpms.
On my bike, when I bypassed that loop ( and cleaned connections), my output went from 12.3 v ( nothing) to about 12.8 v ( something) at 2000 rpm. I'm still using the original r/r and I check it over the rpm range to ensure it's behaving. IF you notice excessive loading at idle, I'd suspect a poor r/r, especially since your battery is fairly new.

 

[Buffalo Bill]

Thanks?

Thanks?

Thanks Tom.
I'll check out the charging volts again, now that I've bypassed the headlight loop. However I'm using a cheap analog multitester, not accurate to .1 volts.
Bill

 

[Redman]

Bill,

15volts should charge the battery just fine, I have gone years and years with less than 14 (better now).

You measuring that at the battery?
Or at the R/R?
If measuring at the R/R, it is possible to be loosing several tents or more along the way to the battery, if any bad connections. Is real easy for a bad connection to be loosing a volt and a half or so, and that volt and a half make it so batteryt really isnt being charged well and make it seem like it is loosing charge over time when really it just wasnt charged that well to start with.

Stator papers have you measure for any voltage drop beteen batt+ and RR hot, and then also between batt- and RR-. And you can do that with your analog meter. I often use my 18 dollar radio shack analog meter rather than going and getting my better digital meter from my work tool kit.

Dave

.