MR1 Top Speed and RPM limited to low 9k: AR230 and 05 FX HO

[CruzinCarlz]

I'm trying to get to the bottom of some performance reductions in both my 07 AR230, and my two 05 FX HO's (All with the MR1 motors). Any help is much appreciated! Thank you.

No warning lights on any of them.

'07 AR230, 400hrs 15hrs since oil, plugs service
- Just had a service by the dealer and everything was said to have checked out.
Problem [HASH=459]#1:[/HASH] Speed seems to be reduced. When the boat was new to me in 2017 and only had 45hrs on it, the speedometer would show ~50mph (I did not check phone GPS speed back then). It now only reads 33-38mph and GPS at 38.2mph in mostly smooth water.
Problem [HASH=460]#2:[/HASH] The port side motor only goes up to around 9400rpm, while the starboard will go to 10200ish rpm. The dealer said they made an adjustment and the computer then showed 100% throttle, but it is the same now as before I had them service it.
Problem [HASH=461]#3:[/HASH] Unrelated to performance, but when the boat is not used for about 2+ weeks the starboard motor will not want to idle at first start. After a couple rounds of cranking it for 20sec, it will start up and idle like normal.

2x: 2005 FX HO, 120hr/ea. 20hr since oil, plugs service.
Problem [HASH=4287]#1[/HASH]: When I first purchased them about 4mo ago, the speedometers would read 54-60mph at full throttle (didn't check with phone GPS) . Now they are both only reading around 38mph at full throttle. Once I noticed this reduction, I did GPS them and it showed a max speed of 45mph. The RPM's on both also seem to be in the 9k's instead of 10k+

 

[Scuba_ref]

Seems odd to be happening in three separate machines. The only thing common to all three would be the fuel. Any chance you have bad fuel in them? There was a gas station on the way to the lake that I learned to avoid - had water in the fuel only after filling there.

 

[CruzinCarlz]

That would be a common factor. They are in a slip, and I fill up with the marina dock, only option is 89 octane. It is a busy marina, so I'm thinking it is probably not old gas.

I called up a local rental shop that services their own rentals. The guy said they used to have a fleet of FX HO's, and they would run 2 cans of seafoam in a full tank of gas once a year to keep them going strong. I'm going to give that a try before pulling them from the water and taking them to be looked at.

 

[MartyParty]

I'm trying to get to the bottom of some performance reductions in both my 07 AR230, and my two 05 FX HO's (All with the MR1 motors). Any help is much appreciated! Thank you.

No warning lights on any of them.

'07 AR230, 400hrs 15hrs since oil, plugs service
- Just had a service by the dealer and everything was said to have checked out.
Problem [HASH=459]#1:[/HASH] Speed seems to be reduced. When the boat was new to me in 2017 and only had 45hrs on it, the speedometer would show ~50mph (I did not check phone GPS speed back then). It now only reads 33-38mph and GPS at 38.2mph in mostly smooth water.
Problem [HASH=460]#2:[/HASH] The port side motor only goes up to around 9400rpm, while the starboard will go to 10200ish rpm. The dealer said they made an adjustment and the computer then showed 100% throttle, but it is the same now as before I had them service it.
Problem [HASH=461]#3:[/HASH] Unrelated to performance, but when the boat is not used for about 2+ weeks the starboard motor will not want to idle at first start. After a couple rounds of cranking it for 20sec, it will start up and idle like normal.

2x: 2005 FX HO, 120hr/ea. 20hr since oil, plugs service.
Problem [HASH=4287]#1[/HASH]: When I first purchased them about 4mo ago, the speedometers would read 54-60mph at full throttle (didn't check with phone GPS) . Now they are both only reading around 38mph at full throttle. Once I noticed this reduction, I did GPS them and it showed a max speed of 45mph. The RPM's on both also seem to be in the 9k's instead of 10k+

Problem 3
Same happened to me. I was not blowing out/revving the water out of my engines after use on the trailer. Once I started doing that, seemed to fix it 95% of the time