250 Pro XS issue

[coachmks]

2016 Pro XS 250. Serial number 2B116352. Last three times I had it out, it is hard to start. After starting, it idles fine. When I hit the throttle to take off, it seems fine, then bogs down and loses RPM. It does this a few times till I plane out. Once planed out, I trim up and use more throttle and the motor responds, then bogs down a couple more times. I lose about 1000 RPM when it bogs down. After about a mile, it runs fine and runs fine the rest of the day. Gas is ethanol free and I add Quickcare and Quickleen to every tank of gas. Any idea what I may be experiencing? I also replaced the water separating filter before I ran it yesterday, but still had the same issue.

[Savage]

Make sure the VST is full of fuel by pumping the primer bulb, until it is rock hard.

[coachmks]

I do that every time I go to the lake.

[EuropeanAM]

I do that every time I go to the lake.

But do you do that every time you start the engine? Important question...

[coachmks]

No I do not. I’ve always pumped it up when I unload the boat. That’s how I have done it with every boat I’ve owned and I’ve done it that way with this boat every time I launch. Just strange that it’s doing it the first run of the day then runs ok the rest of the day.

[EuropeanAM]

What's worked with primer bulbs in the past is honestly just that... in the past. Today's fuels are NOT what we used in yester-years.

Since you indicate it happens even on the very first start of the day, you'll want to check all of the BASICS: Compression, Spark, Air/Fuel Pressure Tests and verify all maintenance is up to date.

When were the fuel filter and spark plugs last changed?

One other area to check: Use an INCH lbs. torque wrench, set to 70 lbs/in, and test the belt tensioner to see if you achieve 70 lbs/in prior to the tensioner contacting the end of it's travel (ie: spring should achieve 70 lbs/in somewhere in it's range of travel). A worn belt or tensioner spring can cause this type of problem.

[coachmks]

Thank you. That gives me a few things to start with.