Don please help me

[grimmjsg1]

2012 Mercury proxs serial number 1B882588 I had the fuel filter changed as routine annual maintenance by a mercury dealer. First time running on water after filter was changed after running for about 5-10 minutes while I was at Wot the engine lost power like I hit the brakes dropping from 6k rpm to 4800 rpm I came off plane and ran back. It happened again on way back. Mercury mechanic checked replaced plugs, checked to make sure thermostats were not stuck open, no fault codes he identified it’s running rich (and still is). Now it won’t run over 5600 rpm and is sucking gas like Chevy 454 with dual 4 barrels. I had the cylinders checked all are winning 5 pounds of expected pressure, new plug wires. He draiend VST and found this black rubber. Fuel line is gray oem with blue writing. What can the issue be my faith is gone with local mercury mechanic if the computer don’t say he don’t know

[Bryanmc57]

Generally if you do something and something bad happens right afterwards, it's related to what you did. I remember reading on here about issues with non oem filters.

[lpugh]

Start at the tank, inspect and replace all fuel lines and bulb, O.H. the pulse pump, replace the new filter and inspect innards

[SilverFox579]

Start at the tank, inspect and replace all fuel lines and bulb, O.H. the pulse pump, replace the new filter and inspect innards

^^^^

[EuropeanAM]

Also would be a good idea to monitor air and fuel pressures while running on the water... if a second person is present, a RECORDING can be done with a cell phone (to review once off the water). Can be VERY valuable... if you determine the high pressure fuel is falling off, switch to LOW PRESSURE fuel (back of VST) and HIGH PRESSURE fuel (STB Rail). You can often see the low pressure side drop pressure first (indicating the VST does not have enough fuel being supplied (fuel supply restriction, pulse pump, filter, debris in passage, needle or float problem).

[grimmjsg1]

Don dropping her off at dealer (who I don’t have confidence in or trust). I told them to change fuel line, bulb, clean and rebuild pulse pump and place any items found in box/bag pulse pump came in. Remove vst clean and place anything found in box. Replace rubber grommets around high pressure pump change filter with oem and document fuel and air pressures in all locations. New clues for lack of better word boat runs better after being first cranked, when idling you can see a chemical film (unburned gas I assume on the water) which shouldn’t be with this motor. Idling is rough, 4500 rpm max before trimming up and slow coming on plane. If not so high I would get all diaphragms changed. I think mechanic failed to drain the vst and garbage got in the system and penetrated something as issue began immediately after he changed filter. Anything else I should mKe sure they check?

[Snowedin3]

I had many issue after changing the filter and pulled my hair out trying to fix them - did many of the same things. Never thought the fuel filter could be bad since it was new. It was bad. changed the filter and problems gone. - Try a new filter.

[scotty34]

I just had a customers 250 pro xs in for a fuel leak issue. His still ran ok but leaked found a piece of the red plastic filter element stuck in the VST needle and seat causing it to not seal and over flow out the vent. Food for thought.

[lpugh]

Don dropping her off at dealer (who I don’t have confidence in or trust). I told them to change fuel line, bulb, clean and rebuild pulse pump and place any items found in box/bag pulse pump came in. Remove vst clean and place anything found in box. Replace rubber grommets around high pressure pump change filter with oem and document fuel and air pressures in all locations. New clues for lack of better word boat runs better after being first cranked, when idling you can see a chemical film (unburned gas I assume on the water) which shouldn’t be with this motor. Idling is rough, 4500 rpm max before trimming up and slow coming on plane. If not so high I would get all diaphragms changed. I think mechanic failed to drain the vst and garbage got in the system and penetrated something as issue began immediately after he changed filter. Anything else I should mKe sure they check?

Need to inspect the needle valve while you are at it, for a quick test you can pump the bulb up till firm and keep applying pressure to, if you feel it slowly collapsing, check for fuel coming out of the VST vent. That would indicate it is not sealing and may very well be restricting flow as well

[EuropeanAM]

I just had a customers 250 pro xs in for a fuel leak issue. His still ran ok but leaked found a piece of the red plastic filter element stuck in the VST needle and seat causing it to not seal and over flow out the vent. Food for thought.

This is a possibility- see it occasionally where filters are installed DRY, and/or attempts to remove with inappropriate tools result in severe filter damage.

[grimmjsg1]

Dealer did what I ask changed all fuel lines pulse pump and cleaned the vst. Dealer says the compressor is “scarred” inside and is cause for loss of power on top end. This is the second compressor which was replaced under warranty. Dealer also says it can be driven for awhile it is not near failure. Does this sound legit or more like a word that sounds like legit ?

[Jtreed99]

If the cylinder walls of the compressor are scarred to the point it can’t keep of enough pressure to make power then the dealer is correct it is not near failure because it has already failed!!! I would not run that engine until I had verified the condition of the compressor and I would find a new dealer.

[SilverFox579]

If the cylinder walls of the compressor are scarred to the point it can’t keep of enough pressure to make power then the dealer is correct it is not near failure because it has already failed!!! I would not run that engine until I had verified the condition of the compressor and I would find a new dealer.

Me either!

[EuropeanAM]

+3... If the cylinder walls are scarred it HAS FAILED ALREADY, and metal is already being transferred into the rails and injectors. <-- note the period

[EuropeanAM]

Play nice with the help, please. Debris in the system is NOT the fault of the system- respectfully, the system is designed to be cooled by clean lake or sea water (not sand, silt, seaweed, hydrilla, sticks, bark, or whatever else may go "bump on the bottom").

If all basics have been checked- perhaps a look at the exhaust (and the passages the exhaust travels through the gearcase) would be a good idea.

[grimmjsg1]

My apologies to the prior gentleman trying to help he indeed was correct the freeze frame fault showed events of overheating; I am at wits end. I had the mechanic change fuel line pulse pump. Can send pics of the inside of the compressor mechanic took I see missing metal on the pics of those walls of compressor it went somewhere. After he changed fuel line and pulse pump ran it today it had less power, barely broke over plane and maxed out at 4800 rpm. You can smell unburned fuel, I had my son clean the prop hub before the run to see what happened and the inside of hub was dark and sooty after running one run. I called the mechanic and told them the same he said marine mechanics is not a exact thing. Don can I haul my bass cat to you I have no faith in the locals here. Again I am sorry to the gentleman I was abrasive to you were trying to help thank you. I forgot I had the compressor changed in 2016 I have read they had a batch with bad reeds and they would warranty out. Could this be the issue in my case causing this issue?

[EuropeanAM]

Drop me an email and we will set it up.

[grimmjsg1]

UPDATE Got my boat back when they called me he said it is running 79 mph turning 5900 rpm. They checked compression, air and fuel pressure, the compressor, and spark plugs. Also unplugged and replugged every connection. The only thing they done else is took the poppet valve out cleaned and put it back in. The boat before wouldn’t get over 127 degrees and run 5400 rpm max idling at 4 psi. Now if idles at 0.8 psi, heats up very quickly to 140 then starts cooling down when running and runs as fast as it did brand new running 20-24 lb water pressure at wot. . The only issue it is not known what was done to fix it. Any ideas based on the boat heating up more, running lower water pressure at idle than before, and running the right rpm range now? I need to know what to look for to prevent it from recurring. I was estatic but concerned since it seems to have just started running right. Has anyone seen a case like this before ?

[KJK]

+3... If the cylinder walls are scarred it HAS FAILED ALREADY, and metal is already being transferred into the rails and injectors. <-- note the period

Your still running the motor, with a SCARRED compressor, that Don recommended replacing, correct.???

[SilverFox579]

If the water pressure you posted is from a Smartcraft device it is below minimum idle water pressure specifications.