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Old 04-06-2009, 10:09 AM   #21
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Have you checked the rubber seal at the top of the water tube, beneath the powerhead?
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Old 04-06-2009, 10:13 AM   #22
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Just had a thought....have you tried putting a hose on the end of the water tube where it would normally go into the waterpump, run the engine and see what the pressure is.
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Old 04-06-2009, 10:58 AM   #23
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Originally Posted by blackbeard View Post
gave her a test last night, still shit psi
realy dont know what 2 try nxt agggghhhhhh
1 Was the pressure high and has now dropped?

2 If it has dropped what changes were made if any?
3 Do you have a poppet valve fitted or just a dump hose?

4 What size washers if any, do you have instead of thermostats?

5 Single or 2 piece adapter plate?

6 All water pressure is obtained by restricting the flow out of the exits, so if you have no restricting washers in thermostats or poppett/dump you will not make any pressure, but will flow lots of water and over cool the motor

Karl
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Old 04-06-2009, 02:24 PM   #24
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Just had a thought....have you tried putting a hose on the end of the water tube where it would normally go into the waterpump, run the engine and see what the pressure is.
jus dropped box and tried putting hose on copper pipe, stil no pressure seems like its dumping water straight out of exshust, took thermstat housing off and can see water in heads but not enough 2 fill them up.
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Old 04-06-2009, 02:29 PM   #25
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Originally Posted by marshan162 View Post
1 Was the pressure high and has now dropped?

2 If it has dropped what changes were made if any?
3 Do you have a poppet valve fitted or just a dump hose?

4 What size washers if any, do you have instead of thermostats?

5 Single or 2 piece adapter plate?

6 All water pressure is obtained by restricting the flow out of the exits, so if you have no restricting washers in thermostats or poppett/dump you will not make any pressure, but will flow lots of water and over cool the motor

Karl
pressure has always been low, powerhead mid and box all fitted 2gether this season,poppet is jus a dump and has right restriction washers in stat housing
i got a single piece adaptor plate and a very sore head lol. .
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Old 04-06-2009, 03:00 PM   #26
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What pressure are you seeing and at what RPM.

Have you got a restrictor in the Dump aswell as the T'stat housings.
Your one piece plate has probably got 4 x 1/8 -3/16(Can't remember exact size) holes in it. Add all these things together and you may have an area bigger than the 1/2 inch feed from the pump and hence low pressure.
I would guess that you are not seeing any temp in the heads either
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Old 04-06-2009, 04:03 PM   #27
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Can you regulate the pressure by restricting the tell tale outlet pipe with a cable tie ?.
The pipework you use from the thermostats etc has to have the right internal dia as well.
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Old 04-06-2009, 05:01 PM   #28
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What pressure are you seeing and at what RPM.

Have you got a restrictor in the Dump aswell as the T'stat housings.
Your one piece plate has probably got 4 x 1/8 -3/16(Can't remember exact size) holes in it. Add all these things together and you may have an area bigger than the 1/2 inch feed from the pump and hence low pressure.
I would guess that you are not seeing any temp in the heads either
not getting any reading on gauge, brand new gauge and pipe 2
havent got temp gauge so cant see any temp avent run her long enough any way
looks like powerheads coming off
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Old 04-06-2009, 05:26 PM   #29
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Before you pull the block off close off the t'stat and dump hose outlets and see if you get a reading

What size holes do you have in all the washers?

If still no reading
check the gauge at the engine end of the hose. you can push the end of a can of WD40 on the end to see the gauge registers. I had a similar situation with a speedo hose pinched and not showing a reading.


If you are getting lots of water flow but no pressure you are not going to find a restriction in the block

I think your only problem is to large outlet area especially for a 2 hole cle
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Old 04-06-2009, 06:11 PM   #30
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the holes in restrictors are small rekon no more then 6mm, il try blocking off outlets in morn and see what happens then
thanks everyone for advise fkn boats
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Old 04-06-2009, 08:27 PM   #31
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Sorry to hear that BB.
I've never known an XR2 to have pressure problems, however there has been a few questions ask on this site about PSI in conjuntion with a CLE & Sportsmaster.
I'm confused, because the 2.5 I now have ran perfectly OK with the standard gearbox (without a pressure gauge), I've added the CLE & a gauge resulting in a problem the same as you have.
There must be some wisard here that can sort things out?
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Old 04-06-2009, 08:47 PM   #32
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I dont think that a gearcase will matter for water pressure on top end.
The water that gets to the water pump is way more the waterpump is able to pump up.

That's what i think... But thats only for high rpm's. I think it can affect it at idle.
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Old 04-06-2009, 08:53 PM   #33
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Roger that BB.
My problem started when running high RPM.
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Old 05-06-2009, 12:09 AM   #34
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Quote:
Originally Posted by marshan162 View Post

6 All water pressure is obtained by restricting the flow out of the exits, so if you have no restricting washers in thermostats or poppett/dump you will not make any pressure, but will flow lots of water and over cool the motor

Karl
Wrong!!!

lots of flow will make the motor run hot as it won't have time to transfer the heat into the water
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Old 05-06-2009, 12:46 AM   #35
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Wrong!!!

lots of flow will make the motor run hot as it won't have time to transfer the heat into the water
So how did you derive that logic.
So you are saying that when the t'stats reach opening temp that they flow more water and the motor gets even hotter?

Or the more water flowing the hotter it will get, so if we reduce the water flow right down to a trickle it will run very cool

I don't think so
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Old 05-06-2009, 05:45 AM   #36
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Wrong!!!

lots of flow will make the motor run hot as it won't have time to transfer the heat into the water
thats right is it the correct size dump holes in the adaptor plate for a steel bore motor or is it a 260 plate with large holes in that dumps to much water, not allowing it to build pressure and hold water in the block to transfer the heat.

steel bore motors don,t transfer the heat as well as nicom thats why they had two piece plates
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Old 05-06-2009, 07:39 AM   #37
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I reckon its the one piece adapter plate thats causing the problem. I tried everything when I had one on my 2.5 and in the end I went back to the standard 2 piece. Theres a guide on Scream and Fly on changing the one piece plate to work on a steel bore motor.
I think the steel bore motors need water pressure to cool the block and the 260/280 (one piece plate) cools using lots of water flow.
Good luck
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Old 05-06-2009, 07:49 AM   #38
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its not quite as simple as that as the 260/280's run a 3/4" pick up tube instead of a 1/2" like in the xr2's etc
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Old 05-06-2009, 07:59 AM   #39
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Quote:
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So how did you derive that logic.
So you are saying that when the t'stats reach opening temp that they flow more water and the motor gets even hotter?

Or the more water flowing the hotter it will get, so if we reduce the water flow right down to a trickle it will run very cool

I don't think so
No, cooling systems on the motors are different, standard 2 piece adaptor plates have the powerhead cooling pipes connected to them and a single small tell tale outlet, the one piece plates do away with the water connections and have 2 larger tell tales/dumps. The thermostats/poppet valves are there on a standard motor to build the heat until it gets hot enough to run correctly, they then open to give correct flow for the cooling system fitted
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Old 05-06-2009, 08:15 AM   #40
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About the 2 piece and 1 piece adapters: I thought all the Xr2's with offshore mids came with a 2 piece adapter plate? Or am I wrong?

I am also converting my 2.5 200 from 1 piece to a 2 piece adapter.
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