YPVS Loses Position(?)

[m in sc]

not a heat issue.

[2steve]

Looking at the Zeel wiring, I only see +12 vdc and the wires to the coil that could be suspicious since they are still embedded in the harness. Everything else has been changed out with the same symptoms as a result.

[m in sc]

yup. look there.

OR, bypass them and make new ones.

[mnein]

Seems like if it isn't fuel starving it has to be heat or something that breaks down with current (amp) load.

[m in sc]

it does it from dead cold startup as well. like said, confounding.

[2steve]

Seems like the continuous 55 to 70 mph speed just kills it off somehow. At that time, with the 15t front sprocket, the RPMs are up in a "good" range. Maybe wiring getting too hot from load and going open or increasing resistance. I dunno.

Yeah Matt, feels just like the bowls go empty but Mark would add that the bowls going empty would make the bike lurch on its way out. With this RZ, it just winds down smoothly to only low rpm or altogether cut off. Got a higher flow petcock on now, for sure.

I rewired the coil ground straight to the battery terminal and the the other coil wire straight to the orange coil wire from the Zeel. Checked the + wire to the Zeel from the fuses and there's no smoking gun. Changed the fuse, just in case. Fuses get weird sometimes. Haven't gotten to try it out yet.

Yambits came in today - 3 days I think. FedEx - NO TARIFF surcharge on $260. I'm even happier about the genuine Yambits sticker I found inside one of the parts boxes.

[1976RD400C]

I'm somewhat confused and possibly a bit stupid. Isn't that the power valve controller in the center of the picture? Do you have a Zeel controller (VCDI10VT)?  Why are you using the oem power valve controller? 

[m in sc]

no the originsl powervalve controller isn't being used and its not on the boke

[2steve]

I'm somewhat confused and possibly a bit stupid. Isn't that the power valve controller in the center of the picture? Do you have a Zeel controller (VCDI10VT)?  Why are you using the oem power valve controller? 

The original power valve controller was still good (located much further back when it was previously in). Yes, that PV control is also built into the Zeel I got from John at Economy Cycle. He very conveniently had it in stock. That black cube in the photo is, uh... I don't know. Red and black wires are the new overly fat coil wires. The new coil from Yambits with the "H" on it didn't help.

[m in sc]

we verified PV operation as well. its good.

[mnein]

The black cube in the photo modulates flatulence output. And at least you got a Yambits sticker to aid in the happiness of this RZ journey that began in Michigan.

[teazer]

I just read back through the whole thread.  Before I did that I was thinking filler cap not breathing, but I got back to the first page and it looks like the same problem is still there after all sorts of changes.

If that is right, then what changed since it ran right, or maybe it never ran right since it was built. If it ever ran properly then the question is what changed. In either scenario I would start by borrowing a different set of pipes and see if that eliminates the issue.

It does sound like incomplete combustion above idle and below say 4,000 which may be an adverse pipe resonance effect. I don't have any dimensions for the #375 needle jet, so I have nothing to recommend as a possible alternate, but I suspect they are like #284 on late model RD400 which were an air bleed type but with the tall discharge nozzle.

[m in sc]

it ran perfect, nothing was changed.tgis was also on a fairly fresh motor. it came on suddenly. therein lies the rub.

[1976RD400C]

Side stand control unit??? That is electronic with a scr in it and is connected to the engine kill circuit. Maybe try disconnecting it.   

[85RZwade]

Any chance you have access to another wiring harness? Swapnostics is a valid technique!