Looking to test run buy a 15" prop for 2stroke 90 HP yama

[Lakesport90]

Lately been somewhat disapointed in the way boat has preformed.
Runs well, but RPM's are off buy a few hundered and now plowing throught water
vs on plain. When trim all the way out motor becomes louder as though trimmed
to high.

Currently run 13 1/4 by 17. max rpm are 5400. With a 15" RPM were 5800 and slightly above.

Any suggestions.

[rangerman1981]

my dad has a tx17 with a 60 we are running a 21 pitch prop on it turning 5700 rpms and the boat rund 42 gps . we took all the wood out and put alum. decks

[Rebel1]

Is this with a new prop or what?

[Lakesport90]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rebel1 &raquo;</TD></TR><TR><TD CLASS="quote">Is this with a new prop or what? </TD></TR></TABLE>

Props about yr old. Had a 15" but was turning 5800 with throttle left.
WOT and trim 6300 with 42 mps by GPs.

17" 5300 Trimmed out but don't have the lift.
This is with 1 person 22 gal gas and fishing gear.

[Rebel1]

The 17 could have a blade that is not right. I would have the prop checked first.

[Gun Runner]

That didnt sound right to me either !!!!!!!!! There shoulda only been 400 Rs difference in the 2 props !!!!!!!!!!!!!

[RogerR]

Damn Gun you been learning from Doug.

[Gun Runner]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RogerR &raquo;</TD></TR><TR><TD CLASS="quote">Damn Gun you been learning from Doug. </TD></TR></TABLE>Dont cuss me like that , Im self taught !!!!!!!!!!!!!

[Gun Runner]

Alotta ppl will tell you different , but Ive owned A few aluminum boats and Ive found that by putting A hydrofoil on some them it will give you A lil more bow lift and pick the Rs and the speed up A lil and also help the hole shot and cornering on the boat . Most aluminum boats keep the motor deeper in the water so the cavitation plate is still in the water while on plane , thats how it helps aluminum boats buy giving it more of A platform to ride on , but most glass boats you can jack the motor up so that only the prop is in the water !!!!!!!!!!!!! Just something to think about . I had A aluminum bass cat that was 18 ft with A 125 merc and buy installing A hyrofoil I was able to play with the jack plate and get more bow lift and A lil more speed ( about 4 mph ) , hope this helps !!!!!!!!!!!!!

[Lakesport90]

sounds good. I have a jack plate, just instaled WP gauge, I think I'll start playing around with that 1st.