RZ350 on E bay

[suey1958]

https://www.ebay.com/itm/1985-Yamaha-Rz350/233827693485?hash=item36713773ad%3Ag%3AsZYAAOSwtwFf3jNT&LH_ItemCondition=3000

[pdxjim]

Non-PV 421 cylinders, probably a handful.

[rodneya]

Non-PV 421 cylinders, probably a handful.

2 into 1 intake and those pipes are probably holding back a lot of power on that setup

[Czakky]

What does pv421 cylinders mean?

[RDFL]

PV- Power Valve, 421cc's He is referring to power delivery, would be abrupt.

[pdxjim]

Stock RZ cylinders have servo controlled variable exhaust ports called the YPVS (Yamaha Power Valve) system. 

These here are aftermarket 421cc cylinders, without power valves.  Typically a Banshee application.

The power valves smooth out the power delivery, and lessen the powerband hit.

Smooth power delivery is less of an issue on a dirt/sand vehicle with limited traction.

[Czakky]

Got it. I'm slow sometimes...

[RDFL]

6500 and reserve met.

[Evans Ward]

Probably a "light switch" abrupt power band but I don't understand the choice to fit the 2-1 with one carb?  Has to be robbing HP and goes against the choice of the mill. I personally prefer the function of YPVS. 

[RDFL]

Be interesting to see if winner comes thru with the cash. seem to rarely do.

[RustyRD]

Here is a collection
https://sacramento.craigslist.org/mpo/d/citrus-heights-yamaha-rz350s/7252083017.html

[rodneya]

Here is a collection
https://sacramento.craigslist.org/mpo/d/citrus-heights-yamaha-rz350s/7252083017.html

Pretty sure that was the guy in a post a while back that sold a RD400 DG swingarm for big $ and when the buyer received his package it was a stock arm.