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Can you please post pictures of the top of both carbs so we can see the area where the choke lever sits.

It almost looks like someone fitted a chock (enricher) to the carb that doesn't have a brass tube and left the choke out of the other carb.  Or someone really messed up with mismatched carbs.
 

On the dyno, we removed the red sox and gained a hp or so.  Then we removed the filters completely and added another 1.

So I fitted the short rounded intakes 9 Too short to call them bell mouths and added another 2 HP at the top end.

I don't think I scanned the dyno chart, so I will have to look for them to see the effect on AFR of the changes.

AFAIK, that is an 87 FZR400 rear wheel.  I have an almost identical 88 FZR400 wheel here that I was planning to use in an RD350 project.

I worked it out 

Did someone mention TZ top ends on air cooled cases? Back in the day, TZ cases used to wear out and replacements were not always available, so racers took to modifying RD cases to take the TZ crank arrangement. Others bougt TZ top ends and fitted them to RD bottom ends.

This is a set of RD cases with a TZ crank and water pump with RD400 transmission and 40900 (64mm bore) top end with bigger reeds. 40970/40971 66.25 TZ750 C/D/E top ends also drop straight an to an Air cooled bottom end.


I forgot how to insert and image.  I'll be right back as soon as I work that out.

A couple of observations.  The ports are close to TZ350 or TZ750 dimensions, and at 17.5cc the heads have been machines to raise compression. Looks to me like someone wanted a full race tune.  Squish is much too large.  The inner squish dimension is supposed to be larger than the outer measurement. It may have been designed to run without a head gasket, but inserting a gasket would increase squish even more.

Looks like the head was machined to be dowelled to the cylinders. The squish band looks to be very wide which is usually for lower RPM motors and the transition from squish to the combustion chamber should not be as radiused. It's as if the tuner wanted to use that head to stock the motor from revving too high even though the ports would support very high revs.

If you are racing it, use 100 octane race gas, but for the street, I would be looking for a pair of stock heads or get that pair machined to take O rings and reduce the compression and make the squish band less wide.

The top one is supposed to be a stock RD350.  The lower one is a full production race TR3 porting.  Do not attempt to port an RD to TR specs.

Sweet.  How do your ignition curves compare to stock?  That's quite a lot of advance as you get close to peak HP revs.  I was also surprised to see less advance at lower TPS settings.  I was expecting to see more advance at lower load (TPS).  We never changed the curves on the Cup bikes but did change Power Valve timing which did change the dyno curves. 

That Wicked design is similar to the way that they do 3 into 1s on a sled with very short header section. The first one has two parallel headers into what is barely any sort of chamber, so I would expect performance to be worse than stock but with a cool sound.

Left side usually runs lean when the oil seal behind the ignition/alternator starts to leak. Clearly that is not what is happening in this case. A couple of thoughts:  Did you do a leakdown test yet? On a Yamaha twin with lab seal it's harder to locate the leak than some other designs, but it's a good place to start.

I wonder if the oil feed nipple or hole in the left carb is somehow larger than the right and allowing surplus oil into the left side. On Suzukis that isn't possible with the pump design, but it's been too long since I messed with an RD pump to know for sure.

Just a point on TZ cranks.  They absolutely do fail and do so quite dramatically.  They are safe on a 250 to about 11k or so and 10.5 on a 350.  More than that and the #3 crank wheel cracks open.

Roller main bearings are great in a bike with straight cut primary gears, but with stock primaries, they need to be ball bearings.

TZ motors have rubber mounts, like an RD400, on the front mounts so as the motor vibrates and moves around, it tears the rear upper mount out of the castings along with the tacho drive.  That's why TZ riders usually leave the upper rear mount at home.

If ALL the crankcase mounts are rubber isolated, then keep the upper rear but if that rear mount is solid and lower mounts are rubber, it could become an issue

PVL race ignitions are great.  Simple and fairly reliable. None of the features of a modern 12v DC CDI, but if you don't have them you don't miss them. They are a race ignition though with no battery charging capacity.

Yes they are.  I haven't ridden hard enough to find any downsides so far. Seem like great tires for an RZ

https://www.continental-tires.com/products/motorcycle/tires/conticlassicattack/

That's what I fitted on the RZ

the needle jet is fixed in the casting

That is probably true for a genuine PWK and would be consistent with Keihin not supplying parts.  Unfortunately the knockoffs are a little different - no surprises there eh - and use the standard 2.60 needle jet as a PWK38.

I wonder what's in clone PWK34's