2022 Mercury 450R Issues

[FISHSTIK]

1. Engine Serial Number 1E089515
2. Year/Make/Model - 2022, Mercury, 450R - 14500013A
3. Prop you are Running - 28 Bravo1, 48-831916
4. Current Maximum RPM - 6,440
5. Idle and WOT Water Pressure Readings - 6 / 25 psi
6. Smartcraft or Analog Instruments? Smartcraft

The motor feels sluggish in the middle rpm range most of the time but not always.
Sometimes when trying to plane out the engine will just surge from 3,000 to 2,500 RPMs. It will continue to do this until you let off the throttle and get back on it at which time it planes like normal - about 5 seconds. It has never done this off the trailer, always later in the day when changing locations.
There are no DTCs
I would greatly appreciate any advice or thoughts.

[EuropeanAM]

May possibly be a fuel supply problem (and by problem, I mean that it may simply be VAPORIZED fuel in the system).

Try permitting the engine to idle (in neutral) a minimum of 60 seconds before shutdown, and a minimum of 60 seconds after startup.

Also suggest trying a totally different fuel BRAND and STATION to rule out some unusual blend of fuel that contributes to the vaporizing problem.

BTW.. that's REALLY healthy water pressure at idle!

[FISHSTIK]

Will do thanks.

[Boatmechanic]

1. It will continue to do this until you let off the throttle...

As Don says, that is typical behavior of a fuel supply problem.

Check hoses, primer bulb, etc, as well.

[EuropeanAM]

There's no primer bulb on a 450R (at least there better not be).

[EuropeanAM]

Hi!

I have exactly the same problem with my 450r. Did you solve the problem?

Please take a moment to review the Announcements at the top of this Forum, and open your own separate thread for your engine/serial number. Be happy to help you then.

Thanks!

[Capt James]

As Don says, that is typical behavior of a fuel supply problem.

Check hoses, primer bulb, etc, as well.

Check FUEL VENT also and make sure it's not restricted. Could also have a bad hose that's collapsing somewhere. I think you should put gauges on it and verify fuel pressure.

[Tim Powell]

The 450 does limit power based on oil temp as well but thats typically only an issue at first holeshot of the day or during the winter. I have also seen issues when running hard to a spot, shutting down suddenly to fish without a proper cool down and ending up vapor locked on restart.

[EuropeanAM]

The 450 does limit power based on oil temp as well but thats typically only an issue at first holeshot of the day or during the winter. I have also seen issues when running hard to a spot, shutting down suddenly to fish without a proper cool down and ending up vapor locked on restart.

Good info, Tim.

And as with ANY Supercharged engine it's always wise to provide adequate warm-up time before hammering it, and ample cool down time before shutting down the engine. This is perhaps just as important as regular/proper maintenance.

[mikeym]

curious if you ever found resolution to this problem? i have triple setup, but having same issues with engine stumbling getting on plane, week mid range, and only pulling 38-39gph at 6000 WOT. motor with same prop previously revved out to 6400 and 44-45gph. replaced all spark plugs 25 hours ago, found one bad plug, all else was good. the motor with fouled plug is burning 10% more fuel at cruise.

im not getting any codes either.

[EuropeanAM]

curious if you ever found resolution to this problem? i have triple setup, but having same issues with engine stumbling getting on plane, week mid range, and only pulling 38-39gph at 6000 WOT. motor with same prop previously revved out to 6400 and 44-45gph. replaced all spark plugs 25 hours ago, found one bad plug, all else was good. the motor with fouled plug is burning 10% more fuel at cruise.

im not getting any codes either.

You would need to open a separate post for your engine, and provide the engine serial number. If you would, please take a moment to review the Forum Announcements (top of Forum) and be sure to follow when posting. Thanks!