Can I run engine on trailer with pump and impeller removed?

[Diezel44]

I just bought a 2007 SX230 HO with only 137 hrs on each engine. This is my first Jetboat, but have been doing all my own work on boats for years. I have read quite a bit about the noise like rattling cans or marbles in a tin can. My starboard engine sounds extremely loud to me. I just changed plugs and oil, and no change. It definitely sounds like it's coming from either the pump housing or Intermediate bearing. I removed the pump housing, wear ring does not appear to have any swell marks or gouges, and the impeller looks good. I ordered new housings for both anyway.
My question is, can I start the motor with the pump housing/ impeller off real quick just to see if the noise is coming from the intermediate bearing? I figured that would narrow it down before I install the new housing and re-install the impeller. I don't want to put it all back together just to find out the IM bearing is bad and needs to be replaced. I also noticed that the hose from the zerk fitting to the IM bearing house was off. I pumped the hose full of fresh grease and then installed it back on the IM bearing house nipple and gave it 2 pumps of the grease gun. We shall see if that helps.

 

[Acard7]

You’ll know if your intermediate bearing is bad if you get on the water and it leaks around the bearing, or reach down behind the engine and give the shaft a jiggle since you have the pump pulled. If it moves then you know the bearing is going bad. I don’t see why you couldn’t run the engine without the pump in, less resistance!

 

[Scottintexas]

Yes with the hose connected, wouldn't hurt to check the cone and bearing for water intrusion

 

[FSH 210 Sport]

I don’t think you can run the engine on the hose with the pump removed because there may Not be enough water flow through the engine with cooling water line from the pump totally exposed. I could easily be wrong about that but it seems plausible.

 

[Beachbummer]

You want to review the house routing and pinch the inbound water hose from the pump, same as if you were towing.

 

[2kwik4u]

I don’t think you can run the engine on the hose with the pump removed because there may Not be enough water flow through the engine with cooling water line from the pump totally exposed. I could easily be wrong about that but it seems plausible.

Agreed. Clamp off the cooling line from the pump to the engine to ensure flush water flows to the engine and not reverse out the inlet line.

Otherwise should be no problem. Heads up, it's going to rev REALLY REALLY fast, so I would use as little throttle as you can get away with.

 

[Diezel44]

Much appreciated guys.

 

[Julian]

A quick 5-10 second run should be no problem. I wouldn't run it above idle or longer than that.

 

[Scottintexas]

here's a video I made running without the impellers and showing how much hose water backflows out the normal cooling water "entrance" without clamping the hose in the engine compartment

 

[haknslash]

Nobody clamps with a impeller housing and pump in when flushing out of the water as you would still have water pouring out the pump. It’s not like the pump is sealing or largely pressurizing the cooling water when on the trailer. It’s just passages where water flows. All clamping would do it increase water pressure to the engine side but even with pump in place you’d still be losing that water pressure. The small strainer holes might give some backpressure but not enough to be significant or rob the engine of cooling IMO.

 

[Scottintexas]

Nobody clamps with a impeller housing and pump in when flushing out of the water as you would still have water pouring out the pump. It’s not like the pump is sealing or largely pressurizing the cooling water when on the trailer. It’s just passages where water flows. All clamping would do it increase water pressure to the engine side but even with pump in place you’d still be losing that water pressure. The small strainer holes might give some backpressure but not enough to be significant or rob the engine of cooling IMO.

I'm confused by this post (maybe I can't translate 5:28am thoughts into my 10am mind)

Are you saying it's not good to clamp your inbound strainer/jet cooling line before the 'Y" connection when flushing your engine on the hose ?

 

[haknslash]

I'm confused by this post (maybe I can't translate 5:28am thoughts into my 10am mind)

Are you saying it's not good to clamp your inbound strainer/jet cooling line before the 'Y" connection when flushing your engine on the hose ?

No that is not what I’m saying.

Im simply saying if you remove the pump (or not) you don’t have to clamp the line. Some were thinking you need to clamp the line IF you remove the pump but I don’t see how that is needed. The pump is not sealing in terms of the cooling passages and doesn’t provide any significant back pressure I can think of. If you add all the holes on the white strainer it likely equates to at least the same diameter of the cooling passage.

Clamping a line or adding shutoff valves is only a thing to do when your IN the water for rescue towing or wanting to flush with non-salt water while docked / wet slipped in the water.

 

[Scottintexas]

No that is not what I’m saying.

Im simply saying if you remove the pump (or not) you don’t have to clamp the line. Some were thinking you need to clamp the line IF you remove the pump but I don’t see how that is needed. The pump is not sealing in terms of the cooling passages and doesn’t provide any significant back pressure I can think of. If you add all the holes on the white strainer it likely equates to at least the same diameter of the cooling passage.

ok, I definitely agree, it's now 1pm so my CPU must be processing better

Clamping a line or adding shutoff valves is only a thing to do when your IN the water for rescue towing or wanting to flush with non-salt water while docked / wet slipped in the water.

or you're trying to push all your salt-away through the engine instead of sending some out the jet intake
or you've got low water pressure at home on the hose and need all your water going into your engine while flushing in the driveway

 

[2kwik4u]

No that is not what I’m saying.

Im simply saying if you remove the pump (or not) you don’t have to clamp the line. Some were thinking you need to clamp the line IF you remove the pump but I don’t see how that is needed. The pump is not sealing in terms of the cooling passages and doesn’t provide any significant back pressure I can think of. If you add all the holes on the white strainer it likely equates to at least the same diameter of the cooling passage.

Clamping a line or adding shutoff valves is only a thing to do when your IN the water for rescue towing or wanting to flush with non-salt water while docked / wet slipped in the water.

I agree and disagree.

I agree the clamp isn't needed because you removed the pump.

I disagree in that I think everyone that flushes on the trailer should use a clamp (or valve) to get increased flow through the engine from the flush port.

 

[haknslash]

To increase flow I raised the water pressure on my house. Around 70 psi gets really good flow.