525 efi no power under load

[Bajap1]

So I did an oil change and changed out the fuel water separator...now I'm in Havasu and the boat has no power, won't get on a plane, idles fine, starts fine but just gutless, I'm thinking air in the fuel line, which I'd like to check first, anyone have any suggestions on the best way to go about it.

Much appreciated!

 

[02HoWaRd26]

Did you replace just the filter on the front starboard side or did you also do the small one on the rear port side?

If only front, not sure how you’d get air in it, unless the filter isn’t right, at which point I’d suggest buying a new filter and prefilling it prior to install and see what happens.

 

[Bajap1]

Did you replace just the filter on the front starboard side or did you also do the small one on the rear port side?

If only front, not sure how you’d get air in it, unless the filter isn’t right, at which point I’d suggest buying a new filter and prefilling it prior to install and see what happens.

Just the front starboard side, we put some fuel in it...only that which was in the old filter. I guess whay I'm saying is everything ran fine prior to changing the fuel filter, so it is the likely culprit

 

[02HoWaRd26]

Just the front starboard side, we put some fuel in it...only that which was in the old filter. I guess whay I'm saying is everything ran fine prior to changing the fuel filter, so it is the likely culprit

Yea I’d definitely go buy another new spin on filter and try that, it’s a self priming system with the low pressure pump that’s directly below that on your sea pump, but i still typically fill it the best i can. Seems as tho you have an air leak or a blocked passage in filter.
Are you having any audible alarms?

 

[Bajap1]

Yea I’d definitely go buy another new spin on filter and try that, it’s a self priming system with the low pressure pump that’s directly below that on your sea pump, but i still typically fill it the best i can. Seems as tho you have an air leak or a blocked passage in filter.
Are you having any audible alarms?

No alarms

 

[counterpart7]

Is the filter too tight?(mushrooming the o-ring) I have no experience with a 525 fuel filter, but I have seen it a few times on diesel trucks.

 

[Bajap1]

Yea I’d definitely go buy another new spin on filter and try that, it’s a self priming system with the low pressure pump that’s directly below that on your sea pump, but i still typically fill it the best i can. Seems as tho you have an air leak or a blocked passage in filter.
Are you having any audible alarms?

Figured it out...old ass gas...new to me boat figures

 

[Bajap1]

Is the filter too tight?(mushrooming the o-ring) I have no experience with a 525 fuel filter, but I have seen it a few times on diesel trucks.

Thanks for helping it always helps when your not the only one thinking lol

 

[02HoWaRd26]

@Bajap1
Great thread to watch here has a lot of great info on servicing that engine.

Mercury 525 Service

Either I am terrible at the search function (and Google) or there just isn’t much information on this. I have a 525. Roughly 150hrs. I’d like to replace the water fuel separator (currently have Sierra 18-7844 installed) and the oil filter (Merc 35-866340K01 installed). I feel as if there is at...

www.riverdavesplace.com

 

[Bajap1]

@Bajap1
Great thread to watch here has a lot of great info on servicing that engine.

Mercury 525 Service

Either I am terrible at the search function (and Google) or there just isn’t much information on this. I have a 525. Roughly 150hrs. I’d like to replace the water fuel separator (currently have Sierra 18-7844 installed) and the oil filter (Merc 35-866340K01 installed). I feel as if there is at...

www.riverdavesplace.com

Thank u

 

[Bajap1]

@Bajap1
Great thread to watch here has a lot of great info on servicing that engine.

Mercury 525 Service

Either I am terrible at the search function (and Google) or there just isn’t much information on this. I have a 525. Roughly 150hrs. I’d like to replace the water fuel separator (currently have Sierra 18-7844 installed) and the oil filter (Merc 35-866340K01 installed). I feel as if there is at...

www.riverdavesplace.com

Well that wasn't it...still runs like balls, I'm gonna change the fuel filter and see if that maybe it....won't get on plane drives like a turd under load, in idle sounds great fml

 

[Bajap1]

@Bajap1
Great thread to watch here has a lot of great info on servicing that engine.

Mercury 525 Service

Either I am terrible at the search function (and Google) or there just isn’t much information on this. I have a 525. Roughly 150hrs. I’d like to replace the water fuel separator (currently have Sierra 18-7844 installed) and the oil filter (Merc 35-866340K01 installed). I feel as if there is at...

www.riverdavesplace.com

Is there a place in havasu that sells the code reader...wondering about limp mode and obviously if any codes, no alarms or anything but I'm wondering

 

[wishiknew]

Have you tried a different prop

 

[Bajap1]

Have you tried a different prop

I have a 4 blade I was going to switch out tomorrow and see...currently a 5

 

[mjc]

Is there a place in havasu that sells the code reader...wondering about limp mode and obviously if any codes, no alarms or anything but I'm wondering

I have reader in my garage in havasu if you still need one.

 

[Icky]

I have a 4 blade I was going to switch out tomorrow and see...currently a 5

This was a joke

 

[port austin pirate]

As was said change filter again make sure you fill it with as much fuel as you can lube the gasket, and try that sometimes the elecric pump will bite the bullet and give out, mine was running fine at speed slowed down idled for a while just quit bad electric pump I also believe there is a small mesh filter on or near the electric pump. if it ran fine befor more than likely filter change will correct it, but check all hose connecters and line for looseness or cracks good luck

 

[Bajap1]

This was a joke

Ya know I've seen It a bunch of times mentioned and always laughed....lil different when it u lol

 

[Bajap1]

As was said change filter again make sure you fill it with as much fuel as you can lube the gasket, and try that sometimes the elecric pump will bite the bullet and give out, mine was running fine at speed slowed down idled for a while just quit bad electric pump I also believe there is a small mesh filter on or near the electric pump. if it ran fine befor more than likely filter change will correct it, but check all hose connecters and line for looseness or cracks good luck

 

[Bajap1]

I have reader in my garage in havasu if you still need one.

Thank you for the offer, it's really appreciated

 

[Fun Times]

Is your engine serial number handy?
There should be a second filter up higher towards the rear...The serial numbers helps tell which design you have to contend with.

 

[Bajap1]

Is your engine serial number handy?
There should be a second filter up higher towards the rear...The serial numbers helps tell which design you have to contend with.

It's the old style inline, not the cartridge style

 

[Bajap1]

This was a joke

Funny thing about a joke....it was the prop lol, boats running bitchn!

 

[wishiknew]

This was a joke

No I was serious also had this problem before

 

[Starloans]

You know, I had a 525 once in a DCB 28 and the same thing happened to me. Idle, crank fine but as soon as you put the gas on it, nothing. It turns out it was a throttle/shifter link thingy on top of the engine where the throttle linkage connects and there is like this throttle travel path dealio on the linkage when you shift into gear that rides a track up and down when you shift to go forward that tells the computer that you are adding throttle and in gear and if it's not on the track or something then you don't go. I know this sounds kooky but it's been a long time and I don't remember all the details. Check the throttle/drive shifter linkage on top of the engine for proper movement and actuation of the throttle assembly to make sure it's working right. It's a very minor part or fix for a very major activity. Good Luck.

 

[Bajap1]

No I was serious also had this problem before

You were correct I was using a maximus 5 blade 26p...changed to a bravo 4 blade 24...world's different

You know, I had a 525 once in a DCB 28 and the same thing happened to me. Idle, crank fine but as soon as you put the gas on it, nothing. It turns out it was a throttle/shifter link thingy on top of the engine where the throttle linkage connects and there is like this throttle travel path dealio on the linkage when you shift into gear that rides a track up and down when you shift to go forward that tells the computer that you are adding throttle and in gear and if it's not on the track or something then you don't go. I know this sounds kooky but it's been a long time and I don't remember all the details. Check the throttle/drive shifter linkage on top of the engine for proper movement and actuation of the throttle assembly to make sure it's working right. It's a very minor part or fix for a very major activity. Good Luck.

 

[DarkHorseRacing]

You were correct I was using a maximus 5 blade 26p...changed to a bravo 4 blade 24...world's different

Whats the spec on that 26p Maximus? LH or RH rotation? 15"? Is it in good shape?

If its a 15x26 LH Maximus and you'd sell it I'd be interested. Doesnt sound like it would do you any good to keep it.

 

[Bajap1]

Thank you I will take a look

 

[Bajap1]

Whats the spec on that 26p Maximus? LH or RH rotation? 15"? Is it in good shape?

If its a 15x26 LH Maximus and you'd sell it I'd be interested. Doesnt sound like it would do you any good to keep it.

It's a 15" RH sorry

 

[Teague_JR]

have you ever run the boat? you said its new to you. I dont think the spin on fuel filter is related to this.

 

[Teague_JR]

if there are no alarms or buzzers going off and it wont get on plane I would be inclined to think it is substantially down on fuel pressure under load. could be a bad or clogged high pressure pump in the cool fuel unit

 

[Bajap1]

have you ever run the boat? you said its new to you. I dont think the spin on fuel filter is related to this.

Test drive before purchase...it's not related to the spin on filter, I replaced it again