Messages

Ordering a coil assbly, plug caps and YPVS cables from Yambits before doing anything else 

Mark, I see your post on swapping leads and don't know what to swap without changing the wrong thing.

I envision doing that, having the same problem but with the other cylinder, and verifying with the temp gun. Then, not knowing what to look for to fix it.

Assembled everything after going through the carbs again. Terrorized the neighborhood and starting to conclude that a cylinder must be dropping out. Starts/idles great, struggles through the low range (apparently on one cylinder) and furiously breaks loose from 6000+ rpm.
Plugs look good, they are gapped right. Left cylinder on the temp gun is a little cooler.
Not the coil, I assume.
Once the drop-out starts, it doesn't recover until the higher rpm.
Will look behind the left crank end cover just to do something.
Off on another path.

Does the RZ have ignition timing control that could have a segment of rpm drop out, due to loss of output?

Thank you guys for the seasoned suggestions!
Matt, this bike is too beautiful to be a turd.

Mine with a Zeel controller cycles when you turn the key on and seems to come back to where it was with the key off. Start bike and it hasn't moved. At 5000 it starts to rotate, 6000 and away it goes and really cranks open.

Actually, that might be just what mine is doing with the revs going up.
I'll watch it while having someone else rev 5 - 6k.
Will raise the needles back up 1/2 step too.
There's still the possibility that it's something stupid simple.

My '74 H1 CDI went bad. I was in college and electronics nerd Ralph down the hall fixed it for me. He had me pick out all the potting first and attained instant hero status.

Oh, it ran great until now. I'm into the carbs and everything is looking fine - so far. Double checking needle heights later, but they were sticking through the mains the same on both sides.
The power valve cycles and goes closed when it starts. Then, doesn't really budge until rpm goes to the power band range. Maybe I'm missing the opening steps in between.
Would be cool to drop in a known good YPVS controller to check before spending the dollars.
So, not discouraged, just feeling challenged. It's an old friend that needs some new parts.

zeel money is smart money spent. 

You can increase the area under the hp/torque curve, right?

I'll tear into the carbs again, just to see if something is amiss. YPVS seems to be moving appropriately. Carbs were synced mechanically, (although the right slide has a longer overall stroke length ) Gonna compare the carb internal lever lengths to see what gives.

Always room for an error on my part.
...hits so hard on the power band.

The cables have seen better days, I'm sure. Sounds like a concern that should be addressed.

Hoping that Zeel money won't have to be spent...

I'll be taking the cover off and revving it to watch valve movement, too.

Loosened up the cables a bit and checked that it was coming to rest in the right place last night.
The bike didn't stall out, but almost did on both rides. I could hear the YPVS hunting around as it was idling way too slow. Hoping that's what the prob was. Will have to report back later.

Also seeing where someone replaced the transistors on the board and "restored" the controller.

That looks really good, Les. Simple programmability, too. Priced pretty good for that. Thanks!

Took the tank off the RZ for lining and 2K clear coat. Not to make it pretty, but to make it hold gas fumes inside instead of bubbling up the paint in a couple spots. Also, ordered a new needle from Toomey because the left one looked a little chewed up. Installed that. Put it all together and rode around the neighborhood.

The YPVS had previously been a little off, so I got it lined up before ever taking off the tank.

While rolling on it in 1st or 2nd, it seems to bog, (or be missing a lot of torque). Then suddenly, about when the YPVS should have done it's thing and is getting out of the way, there is a sudden torque hit. I mean light switch sudden. Learned to lean over the tank just to compensate for that.

Got back to the house (twice) and the YPVS is full clockwise with the engine off. Should be at counter-clockwise "home" position. Turned the key on and instead of 2 moves turning clockwise to open and then back to home, it makes three moves and DOES find home position by itself. Both times. Seems like it should be fine. Why would something go wrong?

Then, what did I do? Maybe disturbed a wire? This was a carb and tank related exercise. Maybe #1 and #2 YPVS cables became too tight and caught up with me?

If any clues, please let me know.

It bothered me that the original petcock would continually drip really slow when I would pull the tank. It was epoxy-modded. so reserve was not a thing anymore.

If you have the OG petcock and there's no vacuum line, it probably has epoxy in the the rotating stem passageway.

There's a thread above from Kawtriplefreak where he did a splendid job working out an RD400 lever style petcock to make it work with an RZ knob. Probably lined up just right. I took the lazy boy route.

As you can see, it is more recessed and a little high. Certainly easy enough for me to turn it though. I'm going with it for now. Would be cool to mix and match parts, but no good plan has materialized.

Had one in the garage. Wasn't nearly as nice. Was gifted to me and had to give it away.

Very nice acquisition!

I would make voluntary runs to the grocery store on one. The wife would be happy about that.

Please share photos if you acquire this little jewel

Bought the TZR125 petcock for $20-something on eBay.
It didn't look good at first. Could have been a couple millimeters lower and could have had a longer extension on the knob shaft to reach out of the side cover hole. The feed barb faces out the back, but it still works.

Has the same familiar positions as the RD400 unit.