YPVS Loses Position(?)

[m in sc]

I wish it was like an episode of house. we would have been done in an hour then had time for donuts 🍩  😅

[teazer]

I did measure them to compare with higher quality calipers.
They were really close to each other at the tip, midway and near the top, plus overall length.

That still doesn't explain why I'm running the highway or interstate in the good rpm range and it slowly winds down to a crawl or completely stops

If it does come to a stop, it will kick back to life like nothing happened. This behavior started the bowls-running-dry theory that has been disproven and appears electrical in nature.

That particular symptom sounds exactly like a partially blocked air vent in the filler cap. Bowls run dry and when the bike stops, enough air gets in to allow fuel to flow. 

[RDnuTZ]

yep, I thought vapor lock too, and it's easy enough to check (on dirt bikes at least) by removing rubber gasket and locating breather hole in the cap and blowing compressed air through it. Had a couple plugged holes in my lifetime. Only other thing that mimics the "runs for a while, shuts down, and starts up easily again" is an ignition coil that goes open circuit winding when hot, but cools down, closes the circuit and starts again. Mark has tons more experience in this stuff than me so I expect he'll solve it soon enough.

[m in sc]

that too has been tested, i thought the same thing.

[2steve]

There is a brand new coil on it. Had never taken it for a long enough ride with the old coil to compare the shut down symptom. So, there's that.

[85RZwade]

https://www.economycycle.com/product/1984-1985-rz350-usa-wiring-harness-48h-82590-50-00-reproduction-harness/
I am generally critical of firing the parts cannon at a problem, but $150 to replace 40 year-old wiring seems like a reasonable step. I surely have an extra harness you could borrow for testing, but once you've paid to ship it across the country twice and gone to the trouble of swapping it out, you could have supple new wires and clean connections and eliminated a possible cause.

[2steve]

I agree, Wade.
And maybe the new coil is part of the problem(s). I have the original to try out on the highway. Separate issue?

John has a plug kit for the aftermarket Zeel to plug into the original harness. So that, along with his harness, is a serious consideration that I'll likely go with.

Then there is the offer from Mark and Marc to help with carbs.

I'll be working thru it all in the usual throw everything at it so when it runs right, I don't know exactly why.

The parts cannon has been a problem so far, and it usually is.

Still thinking about the previous reminder that I changed a rough looking needle to a new Toomey. The reason was because the carbs wouldn't act like they were synch'd but not because it wouldn't really run well. That was probably the left side float difference.