No mid range on throttle?? Please Advise

[Toyoduck]

Hi All. This is my first post on this website, although i have been a long time reader.  Thanks for all the great info on here. There is very little I have not been able to find.  I have a 2001 SX22 Vdrive. I am out of utah and im usually running the boat at around 6k in elevation.  It is fairly new to me and we have had a blast on it so far. Engine idles perfect, gets out of the hole great and when i pin the throttle it has a great powerful high end. The problem I am having is when i have the ballasts full and the boat is loaded with people i dont seem to have much of a mid range, from about 40-80% throttle nothing really happens as i move the throttle, then at about 80% it seems to hit a giant surge of power that Feels like WOT. when surfing I can either hold around 8-9 mph and slowly move the throttle and nothing happens till about 80% and it jumps to about 13-14 MPH which is to fast. Same when pulling a wake boarder. Holds about 15mph no problem and i need just a little more throttle i slowly engage it until it hits a spot where it really opens up and ill shoot to like 25+. Cant seem to find a sweet spot in between no matter how slow i move the throttle it does not do much until that same spot and it has a blast of power and its to fast. Just curious if anyone knows if this is Electronically regulated or if it has to do with throttle cable or what? Any advice would be appreciated.

I have made sure the throttle cable has no slack in it and it is nice and sooth and tight.
Spark plugs have been changed and the engine has solid compression all around. Starts Great, idles great.
Any Ideas??
Thanks in advance,
Matt

[Sammamish Skier]

This sounds similar to something I experienced last year. Clogged fuel injectors. At mid throttle the boat would surge and stutter. After a tank or two of fuel and injector cleaner the problem resolved itself.

[Toyoduck]

Appreciate the tip. I'll get some good fuel injector cleaner and use it for the next couple tanks of gas and see if it gets any better.

[ootyboy]

Have you always used this at 6000 feet? Given the thinner air you might to change your prop. I had the same issue when I moved my boat to Tahoe - I could not get over 10 MPH until I changed the prop. I think @ 6000 feet you lose nearly 20% of your engine power. 

[Capt Rick]

That's why we offered a change to v-drive from 1;2 to a 1:4 ratio.  $2230. exchange
Also remove and clean mass air flow sensor noting how it is installed. 

Factory used a Acme prop depends on max rpm when loaded with ballast and empty

Capt Rick

[Toyoduck]

Appreciate the advice. This is my first Vdrive and i am pretty novice. Not sure if the prop thats on it is the right one for higher elevation but some advice on if its the right pitch or recommendations would be great. Numbers on Prop are 449 13x12.625v No idea what brand it is or if its at all what i want.  Its a 3 blade. Will clean the MAF Sensor as well. Thanks again. Matt