2019 MERC 250 PRO XS 4s POOR PERFORMANCE….SLOW ?????

[washprotim]

2019 ranger with 250 4s poor performance
60 mph max speed
5400 max rpm
23 fury…correct prop with no issues
atlas plate….tried all different heights
motor sounds good and seems to run smooth
Anyone else had same issue or know what the issue may be ???
Will be taking to dealer for service ,thank you

[Extremeboating]

Based on the specs of Mercury's website it appears you need to be within the 5600 - 6200 RPM range. Of course I cannot give you exact information because you have not started if it is a ProXS and you haven't posted your serial number of the engine.

Based on the info I have at access to (which may or may not be right) it would almost seem as if the issue is actually an over pitched prop issue and you may need to go with a 21 Fury if that's design type prop you want to stay with. However, being that you have a very large prop and they are VERY expensive the bigger the motor I would consult with your nearest dealer and check to see if they offer a loaner program so you can try out a 21 pitch before you go out and just buy one. I would also use Mercury's prop selector web page just to confirm that the RPM range it will put you in will be one that will not put you in an overrev condition, though I doubt it will.

Better to be on the hotter side of the RPM range than the lower as it will ensure you are making the rated power your engine is at that RPM. As has been mentioned in other threads, it is a good baseline to go off, but it's not gospel (albeit I found their info matched my RPM output dead to rights for my setup, speed was pretty darn close too).

Don't expect to go much faster with a 21 foot boat though. My buddy's 20 footer glass boat has a 225 ProXS and he can go no faster than 63 MPH.

I'll let some others chime in, but I think this is pretty good initial info for you to go off of.

[fishnfireman]

First question. Has the throttle (demand linear) been set by computer ?

[SilverFox579]

Second first question engine serial number is?

[Bassin Bob71]

Not sure what 2019 Ranger you're running (520/521, L/C) but something surely isn't right given the numbers you're getting. The best setup on the boat in my siggy is motor height of 2.75 below pad and a true pitched 23P Fury 3 blade. I don't run a hot foot and my boat with twin 8' blades, dual console, Ghost TM and 4 group 31 batteries (non lithium) has ran 73.5 at 6150 RPM solo before I ran out of water. I know under the right conditions mine is a 74 and change boat and I've heard of others getting 75 with theirs.

If you have a hotfoot, its all about a correct demand linear setting, correct motor height and having the prop true pitched. Motor of course needs to be healthy as well.

[EuropeanAM]

Let's start here:

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

Also, have you had the engine put on the G3 Diagnostic System and confirmed for CERTAIN that you are reaching 100% Demand Linear at WOT?