Bravo 1 low water pressure

alldodge

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When cold my mechanical gauge (open cool, attached to block drain port) showed at around 7 psi cold. Thermostat opened and would see 4 to 5 psi.

Cruising (3600 to 3800 RPM) would see around 25 to 30 and on end of year 2 on impeller would see 20 - 25 at cruise
 

skyman2112

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Aug 7, 2015
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When cold my mechanical gauge (open cool, attached to block drain port) showed at around 7 psi cold. Thermostat opened and would see 4 to 5 psi.

Cruising (3600 to 3800 RPM) would see around 25 to 30 and on end of year 2 on impeller would see 20 - 25 at cruise
Those are great numbers. Mine takes about 5 seconds to get 2.5 psi cold at idle, and 25 seconds to get 2 psi warmed up at idle. Crazy
 

skyman2112

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My condition is worse, low PSI even when starting it cold, only 5-10psi at cruise. Thinking it may be a problem on the intake side of the pump. Hose looks perfect going from L/U to Transom. Could be the transom fitting i may pull the drive and look inside with a scope.
Checked the new pump and impeller just to make sure i didnt break a blade off, backflushed the water hoses at the inlet of the pump and the drain housing that goes back to the pump outlet, water was flowing didnt seem like it was plugged. Ill attach some vids. About ready to add a seperate water intake/ thru hull fitting next.
 

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Scott Danforth

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Are you reading pressure on vessel view or eith a mechanical gauge?
 

tpenfield

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Your outdrive has the nose cone inlets as well as the side inlets. You should block off the nose cone inlets while running on the muffs.


A cloth and a couple of bungee cords will do the trick.
 

skyman2112

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Your outdrive has the nose cone inlets as well as the side inlets. You should block off the nose cone inlets while running on the muffs.


A cloth and a couple of bungee cords will do the trick.
didnt you see my duct tape LOL. I only removed the tape when i was back flushing the hose
 

alldodge

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I'm not seeing any issue with water flow. Hope someday someone will come up with a fix to fake the sensor to the ECM
 

Scott Danforth

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rinda and vessel view are looking at the failure prone sensor

I would unscrew the sensor and screw in a good quality mechanical gauge and read what is going on.
 

skyman2112

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rinda and vessel view are looking at the failure prone sensor

I would unscrew the sensor and screw in a good quality mechanical gauge and read what is going on.
this is my 4th sensor. Clearly theres enough water coming through the hose as seen in the videos. Not sure why its so hard to build pressure on startup. Gonna pull the drive and check the thru hull fitting, after that ill add another external thru hull pickup this problem is 5 years old
 

skyman2112

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I'm not seeing any issue with water flow. Hope someday someone will come up with a fix to fake the sensor to the ECM
i had a sudden drop in pressure readings this year, as if a blade had broken off. When i found it the impeller was fine i started reposting to this thread. Since changing the sensor didnt do anything i assumed my problem is getting worse after years of staying the same. If im using the muffs and forcing water into the drive with a hose, everything functions normally weather the engine is hot or cold. Instantly has 2.3 pounds of pressure. In the lake it takes 30 seconds or more to finally get that much pressure. And at cruise its only reading 5-10 psi now where before it was hitting 15.
 

ScottinAZ

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i had a sudden drop in pressure readings this year, as if a blade had broken off. When i found it the impeller was fine i started reposting to this thread. Since changing the sensor didnt do anything i assumed my problem is getting worse after years of staying the same. If im using the muffs and forcing water into the drive with a hose, everything functions normally weather the engine is hot or cold. Instantly has 2.3 pounds of pressure. In the lake it takes 30 seconds or more to finally get that much pressure. And at cruise its only reading 5-10 psi now where before it was hitting 15.
You may have hit on your issue when you stated there is no issue on muffs. As stated the muffs are pressure feeing the pump. In the lake you don’t have that, so I would be checking the suction side of the pump for air leaks. It won’t take much to ruin your suction and cause flow issues.
 

skyman2112

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You may have hit on your issue when you stated there is no issue on muffs. As stated the muffs are pressure feeing the pump. In the lake you don’t have that, so I would be checking the suction side of the pump for air leaks. It won’t take much to ruin your suction and cause flow issues.
yeah i posted a video of the water flow through the transom. I hooked up a garden hose inside the boat and back flushed it. Seems like enough flow but if i had an air leak it would not show up in this kind of test. Maybe i should look on the inside of the transom to see if the fitting is leaking water. I could try and hook up a clear hose to the pump and check for air in it with the boat in the water the same test i did years ago with no luck but maybe its worse now, anyways see for yourself in my previous post and let me know what you think about the water flow. Thanks
 

skyman2112

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Well i stuck a camera on the transom to check out the thru-hull fitting and doesnt seem like a problem but its hard to get a good angle on it. Can see a little grease dripping off the steering arm from above, at first i thought it was rust but when i zoomed in its just grease. im gonna focus on checking for air leaks next.
 

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skyman2112

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Finally found the problem, piece of impeller stuck in the cool fuel fitting. The hole in the fitting is only the size of your finger, even though the hose is 1.5 inch. So the v shaped piece of impeller perfectly wedged into the hole but allowed enough water through to function.
When the thermostat was closed, it would allow the pressure to build quicker and keep the alarm from going off. When the thermostat was open then it couldnt suck enough water in time to build pressure before the alarm went off. That was the main obstacle in troubleshooting this thing. 5 year problem solved. Neve knew the cool fuel fitting existed let alone had such a small opening. Thanks again for everyone who spent time on this over the years!!! Special thanks to alldodge
 

skyman2112

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I'm not seeing any issue with water flow. Hope someday someone will come up with a fix to fake the sensor to the ECM
Thanks for all your help over the years, i just posted the solution to my problem it was indeed a restriction. I owe you dinner buddy
 
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