Polaris ATV Forum banner

Water Pump Mod for 400 2 stroke

30K views 23 replies 12 participants last post by  lateburd 
#1 · (Edited)
Hi all,

I'm tired of this worrying about water pump seals and bearings going out
in the 400 2 stroke engines :motz:, so I am coming up with a Mod for them.
I am getting RID of the WATER pump in the Engine and replacing it with
an Electric water pump!

I'll take out the water pump housing and cap off the water pump pipes on the case. then connect the Electric water pump to the Radiator and the
other side to the Head/Jug to pump fresh cold water into then leave the return hooked up as it normally is.

The water pump I am looking at will handle 24 hours a day by 7 days
a week, with a life of 20,000 hours or 5 years running all the time.

It is also designed to be water proof as it can be submerged in water and
can pump boiling hot water up to 212 deg F, which is great as the 400
over temp light kicks in at 205 deg F.

Here are the specs for the pump, when I get one and install it I'll let you all know how good it works. If it works as good as I think it will, everyone can stop worrying about the water pump going out and destroying your engine!!!

I'll take pictures of the install when I get the pump installed and tested!

Specification:

Input: DC 9V~12V
Motor type: *** 3 Phase ***
Speed control: 0-5V analog or TTL
Output: 30.0L/min (8 gallon/min)
Pressure: 6.0psi <-- (Maybe a problem the Radiator is 13 PSI Max)
Current: 3.8A @12V
Intake: G1/2 (20mm)
Outlet: G1/2 (20mm)
Life span: > 20,000hrs @ 1,600rpm~6,00rpm
Noise: << 35dB
Self prime: no <--(Not a problem as the water pump is at the bottom)
Working Temp: 100'C (boiling water) = 100°C = 212°F
Envir Temp: <50'C (submersible)
Size(L*W*D): See picture
Weight (net): 18.0oz
Weight (Pkg): (2lb)

If it works this should be a sticky for all 400 engines!! :nixweiss:

Mike. :trink4:
 

Attachments

See less See more
1
#2 · (Edited)
Found what maybe a even better pump than the other one I first listed! It handles up to 260 Deg (F)!!! That's over 55 Deg more than the engine will ever get! and it' Cheaper! About $50 cheaper, at a cost of around$55 and sold in the US.

It also accepts a wider range of voltages, from 9VDC to 24VDC with a normal operating voltage o 12VDC.(Don't know anyone who rides 24/7 but if you do it's good for 4 years!)

I'll keep everyone up to date as I test out these Electric Water pumps.

Thanks!
Mike
 

Attachments

#4 ·
Hi,

The TS5 for $55 in the second post is better and runs from 8V to 24V so you don't have to worry about over voltaging it when charging, voltage on ATV willl run from 12V to 14V while charging.

I haven't been able to test it yet due to cash flow problems, my 400 is still none working :(

The GPM should be more than needed, and I think it will put out at least the same if not 2x or more than the original pump, so the motor should stay nice and cool.

You would have to close up a lot of holes and to make sure no WATER from mud n such get into the motor and by removing the water pump I would put the water pump case back in just leave out the bearings and pump itself, also it will take more counter balance oil to fill in the open pump area but that's not a problem.

Let me know if you want more info.
Mike
 
#5 ·
You could also put the pump casing back in and put the water pump gasket and shaft seals in it to seal up the pump so the counter balance oil dosn't leak out thur the pump.

also seal up the WEEP hole with blue glue (gasket) this way the counter balance shaft can still ride in the water pump case but be sealed up from leaking out your oil, and seal the inlet and outlet water pipes on the outside, you can find rubber caps to go over them somewhere I am sure I'v seen them.

Mike
 
#8 ·
polaris 400 water pump mod

I just got mine all put together and seems to be working flawlessly. The only problem i can see is the ts5 is not waterproof. In the info it came with it said "water contact will destroy the pump". If I would'of known that I would have got the first pump. I plan on taking the water pump housing and impeller off and tig welding all the holes. I will try 2 get some pics up. Also I'm going to attempt to waterproof this pump.
 
#10 ·
Update

Well so far so good. Everything seems to be working fine as far as i know (its been like 20 degrees out lately so i havnt felt the need to ride it for a long time) but one day it was about 40 and i rode it almost an hour and everything went well, but still not putting very much stress on the cooling system. It is really important that you get all of the air bubbles out of the system. The pump will shut down if it senses it is dry running. I think I got the pump waterproofed fairly well also. What i did was took a 3" piece of radiatior hose from a chevy 350 (lol) (u could use any 1 3/4" hose). Made a cap using a 2" hole saw out of a random piece of sheet metal. I clamped the steel plug the hole saw cut out into the radiator hose and ran the wires through the pilot hole and silicone-d them up. Wala only time will tell if it worked. Oh yeah one other thing you will get raped if you get brass fittings for the pump $40! ouch!
 
#11 ·
I see, you got screw on brass fittings to connect the Radiator hoses to the pump. I thought the Ts5 was water proof, but sorry if I made a mistake. I think a water proof electrical plastic box would be good to put the pump in.
Would like to know if you think it is pumping as much or more water than the built in water pump of the 400? Does your radiator stay cool too, that is a sign the water flow is keeping the engine cool if it flows more water thur the motor than it can heat up.

I am glad someone tried this, I was going to do it myself but ran into engine problems :( need to rebuild the whole thing. what did you do for the water pump in/out pipes on the engine and did you notice it took more counter balance oil?

Mike
 
#12 ·
Well there's not really a lot of room to put the pump inside of something plus it would be kinda hard to seal around the hoses inlet and outlet. I took the 400 out into the snow last week and the pump is still workin after my waterproof job so it mustof worked. The pump flows plenty of fluid, I can feel the head get really cold when I turn the ignition on. It is still below freezing out still so I cant tell a lot untill summer... I just got some rubber caps for the inlet and outlet of the pump and left the balancer in.
 
#17 · (Edited)
I've got a Davies Craig electric pump. These are built for this application.
It's an EBP23 part No: 9050 for 500cc to 1000cc bikes. (23LPM)
the EBP15 (9002) for bikes up to 500cc (15LPM)

They are a DC brushless motor that can handle -40 > +120 Celsius.

Saves a full tear down of the motor as the water pump comes off the oil pump.
In my case the shaft has snapped on the water pump side so I have no choice but to use the electric pump. ... works like a charm. Only a few hrs on the pump but where i live its desert hot in summer and in the minus in winter... yep stupid weather.

I'm also considering installing a water flow meter, as a fail safe. It'll alarm if the electric pump fails.

Does anyone out there actually know the flow rate of the original water pump. I'm sure 23lmp is fine but it would put my mind at easy a little.
 
#21 ·
I just picked up an ebp15 as well and plan to install on my 97 xpress 400. Have the same issue with the on board water pump. Motor still runs strong and I don’t want to throw a ton on money at something the kids will putt around on. I plan to go pre mix and run it. Sorry to revive an old post but this gave me some inspiration to get this old Polaris runnning again, so thank you!
 
#22 ·
No need to go premix - the counter balance drives both the water pump and oil pump - as long as the crankshaft drives the counter balance, the oil pump will still be operational even though the water pump has been bypassed.
 
#24 ·
If you are not going to remove the oil pump, you need to run a line from the in to out fittings with oil in the line - the oil pump will seize if let run dry and damage the gear on the counter balance - if that happens it will let pieces float around the crankcase (not good) - running a line from one side to the other will let the pump circulate oil and not run dry.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top