Need help with power issue

[AirtoMud]

2004 SANTE that has always run great. I had the interior completely redone at C and S Marine this winter and I also had the carpet and throttle panel redone. I put the boat in last week and drove it 30 minutes to our dock. Ran great. I loaded the bags up to surf my son and I couldn’t maintain 10 mph. The Perfect Pass kept saying more throttle but I had the throttle lever almost full forward. RPMs were normal around 3400. I turned PP off and had the same issue. So- unweighted the boat drives fine and planes out. Weighted- I can’t maintain 10 MPH and it seems like the throttle lever is against the stops. I’m wondering if this could be some kind of throttle linkage/cable tension issue. Thanks for any suggestions

[jpwhit]

Go here and do the Linkage Test and the Servo Motor Auto Tighten Test as a first step.

https://perfectpass.com/support

[AirtoMud]

Thanks! I’ll start with that.

[AirtoMud]

Ok I completed both those test and everything worked the way it was supposed to. Any suggestions on what to try next?

[jpwhit]

Has the boat worked before with the amount of weight and prop for surfing?

Also, do you know the boat's typical top speed before without ballast or many people in the boat? If so, what is the top speed now.

It sounds like the engine may simply be down on power. But I asked the first questions to make sure nothing significant has changed since you knew it worked.

[AirtoMud]

It definitely worked no problem with full ballast for surfing and the 1578 prop I use. Took a little longer when wakeboarding but this is a significant drop off from one season to the next. That’s what makes me think it’s something specific that’s happened. This is just a guess but top speed when it’s only me in the boat is a little over 30 I think.

[jpwhit]

Sounds like the engine just is putting out as much power as it did before. Unfortunately that's not easy to diagnose over a forum. Can you tell if it's possibly missing on a cylinder. If it's a GM 5.7L based engine the cap and rotor on those are known for causing misfires and cross-firing if they haven't been replace regularly.

[AirtoMud]

There seems to be a very faint clicking noise at idle. I replaced the serpentine belt last year and that doesn’t seem to be where the noise is coming from. Again, it’s very faint. I haven’t noticed any noise that seems like it’s missing on a cylinder. I have the engine serviced every winter at the Nautique dealer and I know they changed the plugs in the last 2 years.

[Rednucleus]

When was last time for change of wires, cap & rotor. I would hange all these & plugs if at 2yrs+

[AirtoMud]

I’ve had the boat about 8 years and I’m not sure I’ve ever had the wires, ,cap, or rotor changed. I’ll check with the dealer today to see if they have changed those.

[srock]

Yes on checking the wires, cap, rotor. Have you serviced your fuel filters?

[AirtoMud]

Thanks for all the great info! After reading the responses about the spark plugs and wires I decided to investigate the slight clicking noise I was hearing. I couldn’t tell if it was a cylinder missing but I also couldn’t rule that out. I changed all the plugs, took the boat out and it ran great. Loaded all the ballast and it still ran great and got up to speed better than it has in a year or more. I should’ve checked the plugs first. Again, thanks to everyone who had suggestions!

[bturner]

Wow, I'm surprised that fixed it but great!

[malibud]

get that cap and rotor !