Trouble with H20B Yamaha VF115 SHO

[H20B115SHOProblems]

Howdy folks,

I have been stalking the forum reading what other people have done with similar problems, tried everything I could find, but still no dice.

I have a 2016 VF115 SHO that is failing to get to 6300 RPM WOT with trim fully down. Gets to ~4000rpm WOT fully trimmed down, but the more I trim up, rpms go up all the way to 6300, but getting little bite due to being trimmed so high up.

Motor has only 25 hours, 220 compression all around.

Replaced the following:

Fuel Bulb
Fuel line from bulb to motor
Canister Fuel/Water separator
Primary Fuel Filter
In-line Fuel Filter
VST Fuel Filter
Spark Plugs
All new batteries.

Cleaned Injectors.
Emptied all old fuel and replaced with fresh ethanol free with yamalube and star-tron.


I am stumped. I don't know what else I could replace? Perhaps low pressure/high pressure pump? I wonder if it might be the valve for the VST Float? Seems like it's not getting enough fuel?
Perhaps lower unit needs service?

Could I have too much prop? it's a proptech ptr3.

Based on readout from motor, the engine has zero hours at 5000-6000 and 6000-7000 rpm range, so it has never performed right. (probably an hour now that I ran it a bit trimmed up)

[bottomfisher]

There is a whole thread dedicated pretty much to your boat / setup at the top of this forum. Quit waisting money on things you think are wrong with the motor and start by ditching the powertech propellor. It is well known they do not perform well on the xpress hulls. Read through the thread linked below.
http://www.bbcboards.net/showthread.php?t=478679

[Arkyarcher]

Do you have a jack plate and what is you prop to pad measurement ?

[jgleu]

In my experiences, I have to agree with Bottomfisher, start with changing that prop!! My X21 came in a year and a half ago with a stamped 25p powertech and only ran up to 5,000rpms. I had the prop tested at a shop and the shop told me it was actually a 28p prop. They said Powertech props are famous for that. I bought a new 25p FXP prop and it handles and performs way better!

[H20B115SHOProblems]

Thank you for the input. So All the way trimmed down, getting 4100 rpm, 32mph is normal? I have to trim up a LOT for the rpms to start going up.


Around 6000rpm, I'm basically kicking water straight up in the air, going 25mph or less.


The prop is the one supplied with the boat new. I may go by the prop store and see about getting a new prop and see if the powertech prop is the problem.


Currently no jackplate, thought I have one on backorder.

[jgleu]

Sounds like its a prop issue to me. Once you do get a jackplate, that will help also but start with trying different props. If I had to guess, you should have around a 21p prop. Try out a 19p prop that is not powertech if my guess is accurate.

[footballfetch]

The powertech prop slips like crazy. I went to a trophy - lost some top end but that sucker jumps on plane and carves now.