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pumpguy wrote: ↑11:43 am Aug 18 2023 Here's something I would consider if I had this problem.

First, see if you can find the ID of the bore in new/unworn condition. You may be able to use your old cylinder for this.

Take both of your cylinders to a machine shop and explain your problem. Ask them to measure the IDs of both bores and ask if they can sleeve the oversize bore down to the bore on your old cylinder.

If I'm understanding this problem, this should be an easy fix for any decent machine shop.

Worth a try anyway.

JimmyB wrote: ↑03:05 pm Aug 18 2023 Any chance you could you post a video of a leak down test, are you loosing pressure from the Center shaft and seal if so this is the cause of the pressure drop, if not its somewhere else. That RH rod part # 46102-1384 and packing part #43049-1076 is a internal part of the motor and I can't see this being the cause of your pressure drop, you could leave that part and packing out and assemble the rest of the motor and do a leak down test to find if the motor is holding pressure, if you are losing pressure that RH Rod is not the cause..

JZ05220r wrote: ↑04:04 pm Aug 18 2023

JimmyB wrote: ↑03:05 pm Aug 18 2023 Any chance you could you post a video of a leak down test, are you loosing pressure from the Center shaft and seal if so this is the cause of the pressure drop, if not its somewhere else. That RH rod part # 46102-1384 and packing part #43049-1076 is a internal part of the motor and I can't see this being the cause of your pressure drop, you could leave that part and packing out and assemble the rest of the motor and do a leak down test to find if the motor is holding pressure, if you are losing pressure that RH Rod is not the cause..

The subvalves when closed are not perfectly air tight. Air will easily travel past the right side subvalve and through the packing seal. There are no problems with the left side because there is a slotted cap with an o ring for an air tight seal. By design Kawasaki wasn’t able to get an air tight seal on the right side because of the governor shaft. The main valve shaft is fine as is the seals for it. Thanks

JimmyB wrote: ↑06:51 pm Aug 18 2023

JZ05220r wrote: ↑04:04 pm Aug 18 2023

JimmyB wrote: ↑03:05 pm Aug 18 2023 Any chance you could you post a video of a leak down test, are you loosing pressure from the Center shaft and seal if so this is the cause of the pressure drop, if not its somewhere else. That RH rod part # 46102-1384 and packing part #43049-1076 is a internal part of the motor and I can't see this being the cause of your pressure drop, you could leave that part and packing out and assemble the rest of the motor and do a leak down test to find if the motor is holding pressure, if you are losing pressure that RH Rod is not the cause..

The subvalves when closed are not perfectly air tight. Air will easily travel past the right side subvalve and through the packing seal. There are no problems with the left side because there is a slotted cap with an o ring for an air tight seal. By design Kawasaki wasn’t able to get an air tight seal on the right side because of the governor shaft. The main valve shaft is fine as is the seals for it. Thanks

Very Sorry, my mistake, WTH was I thinking, for some reason I thought the center shaft seal was on the outer side of the RH rod on the cylinder.
You could try with the packing installed on the RH rod wrapping a few layers of Teflon tape over the packing and install it to see if it makes a difference for the pressure loss, might have to experiment with more layers depending how much it is worn, this won't hold up to running but will give you a better seal for a leak down test or wrap the inner grove for the packing with a narrow piece of Teflon tape to stretch out the o ring, would increase the OD a bit.
You could smooth the rough area, take a 1/4" rod, slot the end of it about 1" lengthwise and wrap it in fine emery cloth and hone it by hand. then experiment with o rings.

John_S wrote: ↑06:42 pm Aug 19 2023 This reminds me...I saw a video a while back from KDXDAZZ where he was trying to seal up the exhaust orings. (Going off of memory here) He took a teflon type of tape and wrapped it inside of the groove and then installed the oring. I wonder if running a layer or two around the groove in your shaft and then installing the packing would give it that little extra size that you need?
EDIT: sorry I see that Jimmy said the same thing above.

Molly's 70 wrote: ↑04:45 pm Aug 29 2023 My Fredette ported 220 w/ RB head & carb mods & Vforce reeds runs really well. I do run VP VPR fuel which is not necessary, but
it sure makes tuning a breeze.

Molly's 70 wrote: ↑04:55 pm Aug 30 2023 The VP fuel just brought the bike to life. The air idle adjustments were, I were more responsive. I know it's an oxygenated, leaded fuel.
Other than that, I can say it kicks ass over 10% ethanol 91 octane I can get out of the pump around here. I don't like the way it smells after combustion. It's over priced, but good quality fuel makes a difference.