Yamaha 25 fuel power issues

Okay, here's the deal. I have no knowledge of Outboards. But, after 66 years of wanting one, I finally purchased a 23' Proline Walkaround Cuddy. Problem: the first time I took it out it cranked up fine and idled great. I have an extra long no wake zone where I live and made it through there fine. When I got through the zone, I punched it --- couldn't get it up on plane. Max RPM at WOT 3000. Came back frustrated. Checked fuel for water - didn't find any but changed fuel/water seperator - "just in case." Took it out again. FINALLY got up to 4000 RPM but still couldn't get on plane. According to GPS data on 22 mph. Road around for about an hour trying to get more speed to no avail. Here's the kicker - that hour cost me 42 gallons of fuel. What gives? Is the boat too heavy for the 250? Or could there be carburation problems? I'm sick. Any help will be appreciated.
Thanks in advance - Skypilot30

Re: Yamaha 25 fuel power issues

What is this rig and motor? Model # would help
New ,used , just put motor on boat and never run before,?
Did you test run before buying?
Has it ever run properly?
Is motor set up properly on boat and what prop does it have on it?
How old was/is the fuel?
What kind of maintenance has been done to this and when?

Re: Yamaha 25 fuel power issues

Do a compression test first to determine the motor is still worthy. If ok then proceed to fuel system for cleaning

Re: Yamaha 25 fuel power issues

1993 Yamaha VX250 76 degree 250TXRR
Compression test 110 per cyl.
just found out that there is no fire to one cyl - excessive fuel use
max 4000 RPM
can't get 23' proline up on plane
bogs down @ WTO
Ran fine last season - What gives???