# Water Pressure Gauge Install



## Chad Cohn (Mar 8, 2018)

So I'm installing my WP gauge with the kit. I have a 2010 Mercury Optimax 90 2 stroke and it apparently is pre plumbed for a WP Kit. My problem is the stock hose is smaller diameter than the hose in my kit. What is the best way to join them? I cannot use the stock compression fitting because of the hose diameter issue. Any help would be greatly appreciated as I am in a crunch time situation.

Thanks,
CC


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## Gatorgrizz27 (Apr 4, 2015)

I’d go to Home Depot and get a compression adapter. The volume difference between smaller and larger hoses may throw off the reading, but you’ll know if it has pressure or not.


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## Smackdaddy53 (Dec 31, 2012)

Is it the hard line kit? Just take a piece of fuel hose that slips over both and use some small hose clamps to suck them tight. 20-25psi is not going to have enough pressure to blow the hose off.


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## Chad Cohn (Mar 8, 2018)

So, installed kit and well either the hose is kinked or I have the wrong wiring. I replace the volt meter instead of drilling a new hole because I don't have a lot of space on my console. I'm going to unplug the water to the gauge and check flow first and than I guess play with wiring. I couldn't find any compression fitting that would work with both sizes of hose so I improvised. If all else fails, I'll remove all of the factory hose and use the same size as the kit. On a good note Atlas Micro Jacker is in and works beautifully. WP kit has become the bane of my existence, too many tight spots for someone of my size. lol


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## Vertigo (Jun 3, 2012)

If you're using an analog hose type gauge, wiring only powers the light. Put the motor on muffs, crank it up, and if water is coming out of the gauge end of the hose, your problem is the gauge itself.


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## Smackdaddy53 (Dec 31, 2012)

Is that a high pressure low volume or low pressure high volume cooling system? 
My Merc 90 2 stroke was high pressure and I usually had around 15-18psi. My Yamaha 70 2 stroke is low pressure, I do good to see 1-2psi WOT. I just like to watch the telltale more than a gauge.


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## Vertigo (Jun 3, 2012)

Here's what you need:
https://www.usplastic.com/catalog/i...tprekmDm-4O5XrmAa96NgW117S0ViONUaApavEALw_wcB


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## Chad Cohn (Mar 8, 2018)

Vertigo said:


> If you're using an analog hose type gauge, wiring only powers the light. Put the motor on muffs, crank it up, and if water is coming out of the gauge end of the hose, your problem is the gauge itself.


 Gauge is brand new, so I'll be checking the line today or tomorrow. Gotta get my yard (1.5 acres) mowed before Thursday, not missing my fishing trip for grass.



Smackdaddy53 said:


> Is that a high pressure low volume or low pressure high volume cooling system?
> My Merc 90 2 stroke was high pressure and I usually had around 15-18psi. My Yamaha 70 2 stroke is low pressure, I do good to see 1-2psi WOT. I just like to watch the telltale more than a gauge.


 I believe it is a high pressure low volume, but I'm not super sure. It didn't read any water pressure at all. Bad thing is also under the deck was super duper tight so I am hoping it's a or something.

Stay Tuned!!!!


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## Chad Cohn (Mar 8, 2018)

So pulled the water line and hooked the hose the factory flush connection and with water flowing and motor running (in idle), nothing. I went ahead and disconnected where I had married the 2 hoses and still nothing. Any suggestions? I'm thinking I'm going to have to run new hose all of the same diameter.


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## DONAGHUE (Nov 18, 2017)

New hose all the way... old hose is kinked or has some other restriction.... use the old hose as a pull snake for new hose....


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## Chad Cohn (Mar 8, 2018)

DONAGHUE said:


> New hose all the way... old hose is kinked or has some other restriction.... use the old hose as a pull snake for new hose....


I used new hose to the gauge, the factory installed hose isn't flowing either.


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## Smackdaddy53 (Dec 31, 2012)

Have you checked the fitting at the head for restriction? They like to get plugged up because there is no real flow through them, just pressure.


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## Chad Cohn (Mar 8, 2018)

Smackdaddy53 said:


> Have you checked the fitting at the head for restriction? They like to get plugged up because there is no real flow through them, just pressure.


That's my next stop on this train but that will take more than a few minutes to do and since I'm working I don't have time for that one. That'll hopefully be tomorrow.


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## Chad Cohn (Mar 8, 2018)

So first off, thanks to everyone that offered suggestions. Turns out the factory Merc hose was obstructed. I clear said obstruction and hooked it to the hose and I saw a trace of movement in the gauge and I didn't have time then to take it to the lake. So fast fwd a few days and down on the coast once I got it in the water gauge and hose started working like charm. Now still working on finding the sweet spot but at one point my 90 was cranking 37-39 mph at roughly 5800 rpm. More than happy and fast enough for me, we were even able to overtake a few 115's at WOT on the Laguna Madre & ICW.


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