2012 VZ150TLR HPDI 2-Stroke won't do speeds between 10-20ish MPH

[jpreardon23]

Background- I bought a used 2013 Xpress XP200 with a 2012 VZ150TLR HPDI 2 stroke on it about two-three years ago. The previous owner had bought the setup new in 2012 and then moved halfway across the country and only ended up putting about 25 hours on it in total. He had it looked over and worked on by a shop before i bought it and it had good compression and they said it was fine. I put about 50 more hours on it the first year i had it and then took it in to a shop before duck season to have them do a complete service on it to serve as my personal maintenance baseline to reference moving forward. They replaced some old items (filters, hoses, etc), did some maintenance just due to the fact it was so old with so few hours, did a link and sync, and test drove it and said it was good to go. I have since put about 50-80 more hours on it this past year and had sponson pods welded on the back to help the transom sit higher.

Issue- At slower, no wake, speeds the bow sits very high and the more i throttle down it just raises higher and higher and i just plow water. I can do this until about 9mph and then once i get it past that point the RPMs and speed will just keep increasing until im going over 20mph even if i dont continue to increase the throttle. On the reverse side of things, when i am on plane and trying to slow my speed as much as possible when staying on plane, it will not hold speed or rpms below about 23mph. It will just keep dropping rpms and speed even without me decreasing throttle.

Bottom line is that I cant hit any speeds between 10-20MPH.

Question- Is this just due to the boat length and not having much weight out front? Is this an engine issue? Is this just the way the engine is due to size, model, etc? Is there a way to solve this or make it any better?

Appreciate any help/feedback!
-Joe

[99yam40]

move some weight forward of put trim tabs on it

[DennisG01]

I googled for your boat - looks like a flat bottom boat. With a 150HP on it, that should scream and come out of the hole VERY easily. The good thing here is that it sounds like your "fix" is a freebie and can simply be chalked up to user error and/or inexperience in how to properly trim an engine for best performance. It sounds like you are not trimming down far enough and possibly not using throttle properly. When taking off, trim all the way down and smoothly increase throttle quite a bit until the bow comes back down. This SHOULD happen very quickly with such a small/lightweight boat. As the bow comes down, trim up a bit and back off throttle to control your speed. To stay on plane at a slower speed, it's a combination of throttle input and trim.

The more weight you have in the back, the more it will squat. But don't put all your weight forward, either - you ABSOLUTELY don't want to plow and end up stuffing the bow.

[99yam40]

my little 1999 16 Xpress came with a tail on the 40TLRX when I picked it up used in 2008.
I worked on the motor and got it running well and took the tail off.
the 1st time I took it out after removing the tail, I had to get my brother to get on the front to keep the bow down even when running WOT.
I put the tail back on and it has done well since.
I think the transom angle is wrong and would require wedges to let the motor trim in far enough to get control without the tail on the motor.
Maybe you have something similar going on

[pstephens46]

So the boat has done this the entire time you have owned it?

Looking at performance reports for bass style hulls in that hp range and higher, many plane at 20 plus MPH. Meaning, there isn’t a 10-20 mph option. You might be able to get a different prop that may help with lower planing speeds. Ken at PropGods gives good advice.