Engine loses rpm's and runs rough after 1 hour running

[NautiqueSS]

First I'd just like to say I love my nautique. It's a 97 super sport with 800 hours on it (bought in 98 with 75) and I honestly have never touched anything in the engine compartment besides clean out the water strainer and change the oil every 50 hours. I run it year round at least 3 times a week and it has never not started, stalled ran rough or died on me so I can't complain but now it is losing rpm's only after at least an hour of use and it takes the boat down to idle no matter how much throttle I give it and will idle rough until I shut it off and re start it. I just changed the v-drive oil cleaned the strainer on it, changed the fuel filter (looked pretty bad) and am going to put a new impeller in today. The temps always stay right at 160 and lately it been getting up to 175 so I'm going to go ahead and replace it since it supposed to be changed every season. So if it's not the impeller I don't know where alse to look. So if anyone has any ideas let me know. I'm glad the site is finally up I was missing the old website. All in all it's been a great boat and I either got really lucky or Correct Craft builds an awesome boat. After 800 hours she's probably just starving for some attention.

[skinautique]

Did you have the fuel control cell update done on it? That could be your problem right there. Also, is your engine light on? Probably isn't that but I figured I would ask. Fill me in some more and I can probably get it dialed in for you

[NautiqueSS]

FCC update?

Well I put the new impeller in and it seemed to run fine. I also drained the FCC to see if anymore gunk had gotten in there but it looked clean. I only ran it for about an hour so can't say that it's fixed for sure but the new impeller did drop the temp down to right at 160 even though the old one looked fine. Are you talking about the light that comes on if the engine is overheated or lost oil pressure cause I don't even know if that one works (it's never come on) or the one that goes off above 1200 or so rpm's which always goes off but I think it has to do with the transmission, right? But let me know about that update, what's bad about the factory one? So far so good. Thanks

[skinautique]

the 1200 rpm light deals with the v drive unit itself. The update for the FCC had to do with the fuel lines near the pump. If you don't think you had it done, have your dealer scope it out. It is an important one to have done. Changing the impeller will not change the amount of RPM's your engine draws.

[lawrence]

Read the second post about uncommanded limp mode. You have the same problem, and will require the same fix.