on lake powell 2017 ar190 top end gone

[tdonoughue]

You are probably off the water by now. I would give the pumps a good once over--pull them if you can to check the impellers.

That is a lot of drop, but it could be altitude, easily. Especially if there is some poor gas in there, too. I don't think that would be just 'not using premium'--it would have to be water in the gas or something. I run regular (with ethanol) all the time, with Stabil 360, and have no issues. Pick up SeaFoam and treat your gas with that. Then I recommend Stabil at each fillup (my regular fill up routine).

And, @Scottintexas , I didn't get an alert on this one either...

 

[steve0617]

Powell is about 3600’ or so. On a NA engine, you’re going to lose RPMs for sure. Where do you normally boat?

 

[dzeppos]

Powell is about 3600’ or so. On a NA engine, you’re going to lose RPMs for sure. Where do you normally boat?

I just returned from lake Powell (altitude 3700 feet). and then went boating at lake mead (1000 feet). You looking at 3700 altitude - equates to a drop of 10-12%power.
Try boating at 5700 feet - more like 20% drop in power

The power drop is noted by the engine spinning less. That’s why your RPMs are in the higher 6890s. On my 242 - i can spin at 7500+rpms or more. Hitting 45-50mph debending upon fuel-weight

At 3700 feet my engines spin at about 6900-7100 rpms. Top speed 41-45.

At 5700 feet - engines spin at 6700rpm - top speed 38-41

Options for high altitude include the “ribbon delete” and or getting higher pitch impellers.

If you will frequent lake Powell and other high altitude laKES - so ribbon delete - good for an extra 3-4 mph

 

[Tlcaffall]

Thanks all that have chimed in. Got back late last night. Haven't gotten out to see if the impeller is dinged. I will try your suggestions. Normally run a local lake at 1500 feet elevation.

 

[Tlcaffall]

Anyone have a link for the best instructions on a ribbon delete. Sounds like that combined with the L13 cone and a new airfilter are the first upgrades.....

 

[sysinu]

This is my YouTube video of it on a 2014 242LS. I have a set of Lake Powell screws. I normally boat at 6500’ altitude. LP is 3500’ - 3600’ altitude based on lake level.

 

[Tlcaffall]

Thank you for all the help, this forum is awesome. Got home and went through mandatory dry out from Lake Powell. Took the boat out and it is running great. So I will say it was just the 2000 ft elevation gain that stole probably 400 rpm's. I would have never guessed. I ordered the L13 cone some 5200 sealant and the ribbon delete kit and hopefully I wont have these problems at higher elevation again.