Labatt, you asked, "Would it be better for us to just flush fresh water through the unit and pump it a bunch to clean it out, and then remove the cap from by the Joker valve?"

Don't even THINK of doing that! Or pumping the toilet any more. K.O. can stay in it till it freezes without harm to the system.

You do NOT have to remove the toilet or even remove the bowl. Spend a little time actually looking at the drawing in manual. Remove the shroud (part # 1246W)....As you can see in the drawing, the base is a pipe...the bowl mounts at one end, the pump mounts on the other end. The plug is at "bowl" end of it. It's threaded in...back it out. Can't recall at the moment whether that requires a screw driver or a wrench...whichever, don't be a gorilla with it. You'll prob'ly have bend over far enough to put your nose at the same level so you can see it...if you're not built to get that low, find a kid who can. Reach into the pipe with anything that'll fit that let you grab onto the cap and pull it out. You MIGHT need to wrap the threads in teflon tape when you replace the plug.

Gene, why not print out the complete owners manual instead of only the drawing? http://www.raritaneng.com/pdf_files/ph_II/L04v0505.pdf

Now about the joker valve... Vic Willman, tech services manager at Raritan contributed the following to my files:

JOKER VALVE 101 (applies to ALL manual marine toilets, not just the PH II)

Most people think that the only thing the joker valve does is acts as a check valve to stop backflow from returning to the toilet or odor from the tank from escaping through the toilet. But that's not a joker valve's most important function...in fact, the joker valve is THE single most important replaceable part in a manual toilet.

Here’s how the discharge half of the pump works: On the upstroke of the piston, a vacuum is created in the area beneath the piston. This causes the joker valve to close tightly, and the flapper valve beneath the pump to open, allowing some of the contents of the toilet bowl to be drawn into the bottom half of the pump. Then, on the down stroke of the piston, the flapper valve is slammed shut, and the effluent is forced out of the bottom of the pump, through the joker valve, and off down the line. But when the joker valve becomes worn and/or there's a buildup of sea water minerals on it, it can no longer seal tightly on the upstroke of the piston...less vacuum is generated when you pump it. And as it becomes more worn less and less vacuum, till finally the bowl contents simply move up and down a bit, but don't go anywhere. Sometimes the flapper valve needs to be replaced too, which is why toilets should also be rebuilt at least every 5-6 years as PREVENTIVE MAINTENANCE.

You prob'ly won't notice the loss of efficiency at first because it's so gradual...same as we don't see that we've gotten a little older than we were yesterday when we look in the mirror each morning. But I guarantee you that if it's been two years or longer since you replaced the joker valve, you need to pump the toilet at least 50% more times to move the bowl contents to the tank or all the way out the thru-hull....IF they're getting there at all any more.

Marine toilets have moving parts that require maintenance. PREVENTIVE maintenance is called that because it PREVENTS problems that have to be fixed. You get to do PREVENTIVE maintenance on YOUR terms, when it's convenient for YOU...unlike repairs, which NEVER are needed at a convenient time.

Oil does not dissolve sea water minerals..it just lubricates 'em.