Need help with converting MSD toilet to just portable, carry off and dump.

[ChooChooSnakeMan]

Hi all new to this forum. A little background. I've owned fish and ski and bass boats for 40 years but this year my wife and I took the plunge and purchased a 26 1/2' bowrider (Ebbtide 2660 Ztrak) so we can enjoy the lake with our daughter's families. Total of 6 adults and 5 kids under the age of 10. The boat has a head with a Dometic 964 MSD toilet. It is plumbed into the boats pump out and vent ports. I don't plan to use the pump out (vacuum really I think) feature so I disconnected the 5/8" vent and 1 1/2" sanitary fittings and removed the toilet from the boat. It appears to have not been used or if used very little. I cleaned it up, filled the upper tank with water and pushed down on the plunger. It works very well and the gate seal is good. So I see no reason I can't use this in the boat but as a remove and just dump at home type system. I need to seal off the 1 1/2" main and 5/8" vent male thread fittings that stick out of the back of the lower toilet holding tank. I've searched for Dometic diagrams and parts list and I cannot find a kit to purchase to seal those two fitting off nor can I find what the threads are so I can just purchase female threaded caps from the hardware store in pvc to block the openings. I'm hoping someone on this forum has already done this and can steer me in the right place. I'm happy to have found this forum as I'm sure I will have lots of questions. My new to me Ebbtide has less than 100 hours on a Volvo Penta 8.1 Gi-J dual prop outdrive. It seems really big to me when compared to my bass boats, even the 21' Skeeter that I traded in. I'm totally new to this type of boat and am already concerned about docking without a trolling motor to help me, LOL! Any help with the fitting threads or point me to a kit that has the two caps to block off the ports will be greatly appreciated. My grandkids are beyond excited for summer to get here so GDaddy can take them out on the lake

 

[Horigan]

Welcome to the forum. I did this years ago and believe I was able to get the conversion parts. Maybe find the part number of the portable toilet you're looking to convert to and look up spare parts on their website.

 

[ChooChooSnakeMan]

Thanks Horigan for the quick reply. All I know is my toilet is a Dometic 964MSD. I've looked at spare parts for that model and I don't find any "kit" to cap the ports off nor is Dometic free with telling what the threads are. I am glad to know that you did it so it can be done. Hopefully someone will post the kit part number or even better what the thread designations are so I can just buy some pvc caps. Thanks again!

 

[dingbat]

Kids only need to go to the bathroom after you leave the dock

Cleaning out a portable head a couple of times in the middle of summer will have you wishing you left well enough alone....lol

After putting the "if you use it, you clean it rule" into effect, its strange how the kids no longer needed to go to the head on the boat.

 

[flashback]

Try environmental marine. Google 964 MSD parts.

 

[ChooChooSnakeMan]

Kids only need to go to the bathroom after you leave the dock

Cleaning out a portable head a couple of times in the middle of summer will have you wishing you left well enough alone....lol

After putting the "if you use it, you clean it rule" into effect, its strange how the kids no longer needed to go to the head on the boat.

Hey Dingbat, LOL at your post and I'm sure you are exactly correct. I plan to strongly encourage non-use of the boat toilet but I know that it will get used some in emergencies. I hope it will be used so infrequently that removing it a few times (it is not heavy at all) and dumping it at home will be more convenient than making an extra stop at a dock with a pump out station. Time will tell, thanks for your input.

 

[ChooChooSnakeMan]

Try environmental marine. Google 964 MSD parts.

Thanks Flashback. I went there and the site will be a great resource but "no joy" for what I need. Hopefully someone will post the part numbers or at least the thread size and thread pitch numbers so I can just purchase female threaded caps.

 

[dingbat]

Hey Dingbat, LOL at your post and I'm sure you are exactly correct. I plan to strongly encourage non-use of the boat toilet but I know that it will get used some in emergencies.

Your too kind....any "emergencies" on my boat involves a 5 gallon bucket

Looking at the parts manual for said unit, the unit has

• Discharge: PVC fitting connects to 1.5-in. (38 mm) ID discharge plumbing.
• Vent: 5/8-in. (16 mm) ID hose fitting

Discharge - 1-1/2" Schedule 40 PVC Cap or Plug depending on the gender
Vent - Could be 1/2" or 3/4" PVC Cap or Plug depending on the gender

 

[ChooChooSnakeMan]

Dingbat, you are on it! Ok in order to help others who might have this problem in the future this is what I was able to find once the members of this forum steered me in the right direction. I contacted marinesan.com for help. Very quickly I got a response from Sonja. She said that they don't carry those toilets or parts anymore but as an example of above and beyond service even when no sale will result she sent me the manual for my toilet which I didn't have and most importantly the part number for the Dometic kit that has the plugs. I've got a kit on order, it has not arrived yet so as a disclaimer while I'm sure this is what I need I don't yet have it in my hands. I will post once it arrives to confirm it is correct and let everyone know the source but in the meantime the kit part number which has both plugs is: 385310236- Pumpout/Vent Caps, SaniPottie 960. I hope this helps someone and saves them some searching. Everyone be safe and have a very blessed CHRISTmas. You can't have Christmas without Christ, Amen

 

[ChooChooSnakeMan]

Well I thought I had a parts kit on order but I got a call today from the supplier who took my order and was told that they had thrown all those parts away:-( Looks like I'm going to pick up a 1 1/2" schedule 40 pvc female threaded cap and a 1/2" schedule 40 and maybe a 3/4" schedule 40 pvc female threaded caps just in case from a hardware store this evening per info from dingbat. I'll post tomorrow if the caps work? Good news is the pvc caps are cheap compared to the advertised cost of the kit that the supplier couldn't furnish. I know way more about porta-potties than I ever wanted to know, new boats just open up lots of learning opportunities

 

[dingbat]

Well I thought I had a parts kit on order but I got a call today from the supplier who took my order and was told that they had thrown all those parts away:-( Looks like I'm going to pick up a 1 1/2" schedule 40 pvc female threaded cap and a 1/2" schedule 40 and maybe a 3/4" schedule 40 pvc female threaded caps just in case from a hardware store this evening per info from dingbat. I'll post tomorrow if the caps work? Good news is the pvc caps are cheap compared to the advertised cost of the kit that the supplier couldn't furnish.

After looking at the kit you posted, the larger of the two certainly is not 1-1/2 NPT threaded cap as evidenced by the two piece design. Looks like a collar off a 1-1/2" trap adapter with a plastic thread protector as the cap

The smaller one still looks to be a NPT cap, but the larger one certainly is not. I'm not so sure about those thread sizes.

 

[ChooChooSnakeMan]

After looking at the kit you posted, the larger of the two certainly is not 1-1/2 NPT threaded cap as evidenced by the two piece design. Looks like a collar off a 1-1/2" trap adapter with a plastic thread protector as the cap

The smaller one still looks to be a NPT cap, but the larger one certainly is not. I'm not so sure about those thread sizes.

View attachment 392604

Well this has been an adventure so far. I purchased a 1 1/2" schedule 40 pvc female threaded cap and a 3/4" schedule 40 pvc female threaded cap on the way home yesterday from work. The 1 1/2" cap fit perfect so the actual pump out opening is now sealed. The 3/4 cap was too small. Looking at the male thread on the toilet fitting it doesn't look tapered. I measured it at 1 1/16" outside diameter. The thread pitch is around 10 or so threads to the inch best I could measure. I believe this might be just a 3/4" Garden hose male thread. The spec for 3/4 GHT is a major diameter of 1 1/16" with 11.5 threads per inch. I will try a simple plastic garden hose cap with a washer in it this afternoon and let you all know if it works but I'm pretty sure this will be the fix. Ace hardware has two 3/4" GHT plastic caps with washers for $2.99 so I'll have a spare if it works.

 

[ChooChooSnakeMan]

I hope this helps anyone wanting to convert their MSD version Dometic portable toilet from pump out to just carry off the boat and dump. The pump out fitting that you have to cap off takes a 1 1/2" schedule 40 PVC female threaded cap ( 1 1/2 Female pipe threads). The vent port fitting needs a 3/4 female threaded garden hose cap. Both items are easily purchased at your local hardware store. Now I've got the toilet converted it's time to move to the next task which for me is to add roller guides to my trailer. My Ebbtide 2660 Ztrak will very easily float off the bunks at the rear of the hull if there is the slightest wind or current. I'm adding roller guides which I'm having custom bent to match the angle of the hull. On my boat it is pretty steep, only 7 degrees or so on the sides of the hull right at the back.