No water Pumping johnson seahorse 35 Hp 1959

[jhromeli]

Hi every one
The motor starts real good in the first attempt, so I think I did a good job in the magneto area, now my problem is that I can?t get the water pumping , I change the impeller and after this, I test in the barrel and I don?t get the water flowing in the thermostat housing is totally dry.
When I tested it , it was without the thermostat, but the check valve , spring and plastic housing in place, All dry. I stop the engine real soon to avoid any damage.
I read so many posts about it (Water pumping) and alway explain the possible solutions.

So far what I have done
1) Change Impeller, new one
2) Check the key is in position
3) Rubber grommets are in place for the pump. And in the top looks good I don?t want to take it out
4) Now the LU ins out again after like 4 attempts.
5) I have to check for blockage passages


I am trying to understand how this pump works and the two cooper tubes. (Do you have a diagram to explain it?)

First question?
Which one of the cooper tubes is the pressure one , (Right or left ) looking from the bottom of the engine, I am assuming is the left one am I right?
I am assuming that one cooper tube is the pressure one to lift the water to the head, and the first place the water goes is in the left side of the head thermostat, when is closed, how it works.

Second Question
The left port of the thermostat housing when I blow itor water it , I just get air or water in the exhaust of the engine is it right? Or should I get water in the cooper tube, because I put water in the top and I get water down

Other Question:
How high it should be the water in the barrel, I am putting water until the prime hole in the water pump , until when it starts the external cover in the motor, the one you take out to change the impeller (A lot of Phillips Screws). Should it be higher?, some posts saids until the exhaust hole is it right?

Thanks for your advice.

Regards
Jhromeli

 

[Scurvy Knave]

Re: No water Pumping johnson seahorse 35 Hp 1959

Those pumps are not self priming. You have to maker sure that the pump casing (the bulge at the top of the LU) is submerged. It will not be able to pull water up the from the water inlet.

 

[ddwilson]

Re: No water Pumping johnson seahorse 35 Hp 1959

might check at the intake and make sure a spider nest is not blocking water from getting to the pump and water is high enough in the barrel, some times takes few seconds for water to get through the motor too.
Doug

 

[kfa4303]

Re: No water Pumping johnson seahorse 35 Hp 1959

HI jh. Scurvy is correct that t you need to run the motor in a test tank with water filled up to about 1"-2" below the main exhaust port on the back of the motor. Aligning the two copper water uptake tubes can be tricky, but you just have to be patient. Here are some handy links that may help with the job.

Reviving a Vintage Big Twin - Part 1
1959 Johnson RD-21 35 hp Outboard Motor Parts (parts catalog with exploded diagrams)

 

[kenmyfam]

Re: No water Pumping johnson seahorse 35 Hp 1959

Get it deep and try again. Quick and simple place to start.

 

[jhromeli]

Re: No water Pumping johnson seahorse 35 Hp 1959

Thanks Every One , I will put everthing Back ont the saturday and I will report Progress.

 

[Willyclay]

Re: No water Pumping johnson seahorse 35 Hp 1959

I am trying to understand how this pump works and the two cooper tubes. (Do you have a diagram to explain it?)

The right-side water tube (aft of the motor looking forward) is the inlet source for the pumped water. The left-side tube is for the recirculation of the water until the T-stat opens. When properly submerged as described by member kfa4303, normally you will only see a fine mist of water exiting the exhaust relief outlet hole. It should expel substantially more water when mounted on a boat that is underway after the motor warms up. The factory manual at the link below is loaded with pictures and diagrams that cover your motor. Check page 468. My RDSL-21 was a reliable runner for many years eventhough the PO had abused it. Good luck with that great old motor!

Boatinfo - 1922-1964 Johnson Service Manual

 

[HighTrim]

Re: No water Pumping johnson seahorse 35 Hp 1959

Cooling water from the lake is circulated through the circuit, then sent to the t stat. If the t stat decides the water is still not up to temp, it recirculates it back to the pump. This cycle continues until it reaches its operating temperature, at which time the t stat opens and the cooling water is expelled back into the lake. You will visibly see when this happens as the cooing water exiting the exhaust relief will become more powerful. You will still get a misting of water even when the t stat is closed, as it needs to keep the exhaust cool so it still expels some.

Here is the catch. You need an operating t stat and valve assembly, otherwise the pump will NOT work. You will get exhaust gas travelling back down to the pump. The water pump works great at pumping water, not so great at pumping air. Try intstalling a functioning t stat, and ensure the rest of the assembly is present and functional.

 

[Willyclay]

Re: No water Pumping johnson seahorse 35 Hp 1959

Great info as usual, Chris! Hope the OP looks at his thread again before Saturday. I would hate for him to overheat that beauty.

 

[jhromeli]

Re: No water Pumping johnson seahorse 35 Hp 1959

Thanks every one, looks thats finally I get w?ter in the system, two things rise up the water in the barrel up to 4 inches below the exhaust, and put the thermostat .

it ran the engine for about 3 minutes no problem in low and high speed, but to much smoke is that normal?

the water in the barrel it was really oily is that right?

 

[Willyclay]

Re: No water Pumping johnson seahorse 35 Hp 1959

Great news! Keep the water in the barrel very close to the exhaust relief outlet hole without covering it to insure the water pump is primed. Lots of smoke is normal when running a fuel/oil mix ratio of 24:1 which is what is specified for your motor. What color was the smoke? Oily barrel water is also normal for those old motors. FYI, be careful running that motor above 1,500 RPM's in the barrel because without the load of pushing a boat, sometimes they fly apart. BTDT, good luck!

 

[kfa4303]

Re: No water Pumping johnson seahorse 35 Hp 1959

+1. Keep the LU well submerged. You want the water level to be about 1"-2" below the main exhaust port. Don't worry about the smoke and yuky water. That's normal. They don't call them "2-smokes" for nothing. Not to worry, the smoke will decrease greatly once you've on the open water. Glad you got her running again.

 

[HighTrim]

Re: No water Pumping johnson seahorse 35 Hp 1959

Glad to hear. I have seen that mistake made by many on these dual line thermostatically controlled Big Twins.

As stated, dont really worry about the oil/smoke, will be less noticable on the water.