possible water flow issue

[jerry]

I am using a 2004 700 efi sportsman motor in my buggy. The stock wire harness had to be bypassed for the water temp sensor. I am using a spall fan and spall sensor that i had to drill out the stock temp senor hole to 3/8 npt to fit the spall sensor into ( the spall sensor senseing end is at least twice as large as the stock sensor end was : this may be an issue: i am not sure). I think the fan is ooming on more then it should i have no way to judge it itis just a feeling. The system cools down great when the fan comes on and i have not overheated yet (i have only been out a few times. The stock and spall sensor are both 195's. The stock sensor could not have been used because it was a two wire and the spall system needed a one wire.

My question is two parted is there a way to check if the spall sensor is causing a flow issue and or how can i find a temp sensor that is a 195 and would work with a single wire system (the auto part store guys were no help: they told me they could get me what i need if i could tell them want the sensor i needed was out of). I have reducer that would work with the stock sized sensor if it were a single wire.

[nutz4sand]

First off if the spall sensor is twice the size where it threads in is it a restricted passage? (Pics would help)

Since you reengineered it you need to check your work.

I have made temp sensors that go in radiator hoses so I could monitor the coolant temps so I would know whats going on. You can buy these too at some places. Sometimes you need to use brass plumbing fixtures to fit the hoses you have and have a threaded fitting on the side for the temp guage. I have even placed these before and after the radiator so I knew how much heat it was loosing.

I am not overly familier with spall but the fan may be coming on just fine and not too much.

The engine may be pushing a lot more weight now than it did? It may have a lot less free air around the motor and the radiator system may have to work more to get rid of the heat?

Not to mention you may have too small of a radiator?

[jerry]

The sensing end is twice a large (in the motor): the passage in the motor is tight. I tried to get a good pic of the passage in the motor but it was not possible.

I have a temp gauge inline before the radator it reads about 205 when the fan kicks on. I have another temp gauge setup inline after the radator and when the fan comes on the temp drops to 160.

The radatoris is out of a honda del sol and is aluminum and has pretty direct air flow

[rockslut]

it sounds fine to me if the fan is cooling it that good.

[Glamisman]

single wire or 2 wire sensor... it does not make any difference which one you use. The single wire sensor requires what it is threaded into to provide the ground whereas the 2 wire sensor requires the wire that is not going to the temp guage or the fan to be grounded.

[jerry]

Glamisman I am not sure I follow the two wire deal: Are you saying that I can run one wire off the two wire sensor to a ground and the other wire to the fan. And when the sensor reaches its given temp the ground is completed thus turning the fan on

[Johnyg]

I have a temperature evaluate inline before the radator it flows about 205 when the fan sneakers on. I have another temperature evaluate installation inline after the radator and when the fan comes on the temperature falls to 160.

The radatoris is out of a ford del sol and is metal and has fairly immediate air flow

[chuckorlando]

Our polaris 400's run up to 205 as well before the fan kicks on and also drops back to 165-170 range. These are 2 strokes and cant get as hot as the 4 banger. Our 500's I beleve run up around 215 or so. I'll double check later on the 700 as my buddy has one in a buggy.

One thing I know pretty certain.... When these polaris engines have a bubble, clogged rad, any blockage, they dont tend to cool back. They tend to boil over and alot of time ruin the head gasket. In some cases they warp heads to. And they are prone to air bubbles in some cases as well. I tend to force fill mine now with the engine running. Shove a water hose in the top of the intake hose before the pump and let it go till the rad over flows

[nutz4sand]

Originally Posted by chuckorlando

Our polaris 400's run up to 205 as well before the fan kicks on and also drops back to 165-170 range. These are 2 strokes and cant get as hot as the 4 banger. Our 500's I beleve run up around 215 or so. I'll double check later on the 700 as my buddy has one in a buggy.

One thing I know pretty certain.... When these polaris engines have a bubble, clogged rad, any blockage, they dont tend to cool back. They tend to boil over and alot of time ruin the head gasket. In some cases they warp heads to. And they are prone to air bubbles in some cases as well. I tend to force fill mine now with the engine running. Shove a water hose in the top of the intake hose before the pump and let it go till the rad over flows

Dunno if you know Chuck but the Polaris 400's I had (many) all had bleed screws on the top of the head to get the air out.

[chuckorlando]

I have an hpd billet head that does not have one. My first go around I did'nt realize there was bleeder till it was to late. In fact I had a ton of over heat problem with the first engine. Bad fan switch, air bubble, head gasket, clogged radiator.