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Hawaiian
06-25-2001, 01:22 PM
When I run it with a hose it stays real cold. However when i run in the river with the gate valve wide open it runs at 180 degrees to 240 degrees. Is there a problem with the pump? the pump seems to be ok. I also back blew the gate valve and water did come out of the nozzle. Last year I did not have this problem? Any help is appriciated.
Thanx

spectras only
06-25-2001, 01:44 PM
Hawaiian,the gardenhose supplies way too much water to your engine,hence the cooler temp.I suspect you have a restrictor a tad small on your exit,that slows the flow too much.What diameter size hoses you run for your cooling?

Hawaiian
06-25-2001, 05:47 PM
3/4" from the jet to T. 5/8" through out the rest.?

spectras only
06-25-2001, 08:48 PM
your hose size is right,so I would look into the restriction scenario!

JOESHOW
06-26-2001, 12:06 PM
Hawaiian, try changing your gate valve to an actual restrictor valve. They look very similiar on the outside but are actually made to restrict flow, where a gate valve is not. A gate valve uses small discs in conjunction with the brass gate to seal off the flow. If aren't used at either the fully open or closed postion it will vibrate the discs (this is not audible in a boat) and can soon cause the discs to come loose in the valve. This can restrict the flow but can sometimes be hard to discover because different flow pressures may affect it differently (i.e. garden hose vs. feed from your pump) The restricter valves are about $6.00 at any plumbing store. Maybe this will help. I am new to jet boats but not to plumbing. Good luck! -Shane

SB
06-26-2001, 12:20 PM
Is there any downside to making another hole in the jet on the opposite side of the hole already there? Twice the water, right?

spectras only
06-26-2001, 01:52 PM
Bump, http://free.***boat.net/ubb/confused.gifsuction housings usually have two waterholes ,what jet you're running?
if it's a YJ JACUZZI it has a screen in the impeller side ,try to remove the nipple and see if it's free of debris.[This message has been edited by spectras only (edited June 26, 2001).]
[This message has been edited by spectras only (edited June 26, 2001).]
[This message has been edited by spectras only (edited June 26, 2001).]

Hawaiian
06-26-2001, 05:26 PM
Can i bad seal in the Jet housing be the culprit. I fill the housing and it seems to drain into the flow? I think.

Oldsquirt
06-26-2001, 06:11 PM
Hawaiian, any chance you loaded up your block with sand, silt or weeds? Only times(twice)
the old Tahiti ever ran hot, this was the problem. Try removing drain plugs on either side of block after running some water thru from garden hose. Residual water in block should run out freely. If not, probe into holes with a small screwdriver. If still no flow, turn hose on LOW and see what happens. If you can't get any water to come out, you may well have a block that is full of debris. I actually had to remove my freeze plugs to get sand out on one occasion.

spectras only
06-26-2001, 09:43 PM
When I rebuild an engine,the first thing I do is drilling and tap the drainholes for a garden hose fitting [brass] so after running into some sandy conditions I can hook up the garden hose to this fitting and reverse flush the block.If you don't get the sand out ,it will pack your block filled up with hardened sand,thus insulate the main bearing caps from the water.It then can cause the bottom end to overheat and destroy the bearings. The expandable plugs in the frustplug holes are an other alternative to quickly removing sand if you have acces to them between the exhaust manifold and stringers.These plugs would withstand the waterpressure from the bowl no problem.

spectras only
06-26-2001, 09:44 PM
When I rebuild an engine,the first thing I do is drilling and tap the drainholes for a garden hose fitting [brass] so after running into some sandy conditions I can hook up the garden hose to this fitting and reverse flush the block.If you don't get the sand out ,it will pack your block filled up with hardened sand,thus insulate the main bearing caps from the water.It then can cause the bottom end to overheat and destroy the bearings. The expandable plugs in the frustplug holes are an other alternative to quickly removing sand if you have acces to them between the exhaust manifold and stringers.These plugs would withstand the waterpressure from the bowl no problem. Sorry for the double post
[This message has been edited by spectras only (edited June 26, 2001).]

SB
06-27-2001, 07:43 AM
When flushing with a garden hose, how do you make sure some water gets to the jet?

rivercrazy
06-27-2001, 07:56 AM
I put a T fitting on my intake water line. When I hook up my water hose to the intake line, water flows both to the engine and the pump. Depending on your setup you might need some restriction in the water line to the engine (past the T fitting)

LS7
06-27-2001, 08:19 AM
I'm sure this has been discussed here before, but I figured I might drop in and refresh you here.
First off many have stated that they have no problems running on the trailer with or without water passing through the pump wjile on the trailer. Since I have not seen these boaters impellers / wear rings I must take them for there word.
Now the theory,
Impeller clearances are tight, the front bearing has radial play and the rear bushing is a support. Thus the impeller is floating, your (for a lack of a better term) O ring is the water between the impeller and wear ring, unless the bowl is filled with water and perssured you can not properly float / center your impeller inside the wear ring.
Sure running water through a tee as described above will supply some cooling but certainly there can not be enough water pressure to center the impleller.
To be absolutely sure of no possible damage disconnect your drive line, or just go by what others have claimed. Just keep in mind every .001 of non seal "might" be another clamp on passing you by.
LS

Oldsquirt
06-27-2001, 09:16 AM
For the record, I was not implying(nor was Spectra Only, I'm sure) that one should run the engine while flushing. The idea is simply to let the water hose pressure remove as much accumulated debris from block as possible.

LS7
06-27-2001, 09:28 AM
Olds,
No problem, just saw a few post here regarding the water hose. Just wanted refresh those that might be removing debris with the motor running.
LS

SB
06-27-2001, 10:13 AM
Excuse my ignorance, my limited experience was with a jet ski. On the ski, I ran the engine with a hose connected to the exhaust pipe and observed some water coming out the nozzle. With my new boat, I will be running in salt, are you saying I can effectively flush without running the engine? I have since observed 2 jet boats, the one I bought running the engine with a garden hose attached. I just rebuilt the jet. Another guy had a garden hose attachment with a visegrips on the hose going to the jet. He said he was letting only a small amount of water to the jet with the rest going to the engine. I didn't buy his boat because the jet made noise which he claimed was normal. I confess to being mystified as to how water can go backwards into the jet to lube it. Do you guys really disconnect the jet every time you start the engine in the yard to work on it?

Oldsquirt
06-27-2001, 10:14 AM
That's what I figured, but thought I should clarify my own post.

spectras only
06-27-2001, 03:29 PM
Oldsquirt answered for me about reverse flushing the block with engine off.Make sure you disconnect the inlet hose at the suction piece ,so the sand won't get to the impeller.
[This message has been edited by spectras only (edited June 27, 2001).]

SB
06-29-2001, 09:54 AM
I don't want this thread to die just yet.

mister460
06-29-2001, 10:49 AM
Just remember if you're flushing the block with the motor off and you have headers that you disconnect, clamp off, or turn your gate valve to the injection lines off. Hydro locking an engine sucks way more than a little overheating!
Oh yeah! I forgot one thing. Could most definitely be sand or crud. I just took my motor out and when it was flipped down side up, out came the sand! About 3lbs of it!
[This message has been edited by mister460 (edited June 29, 2001).]