Outboard issue- New prop or something else? "stuck in the hole"

 Hi guys,

I have recently purchased a 5.5 southwind (fibreglass) with a 130 yamaha 2 stroke salt water series outboard. 

I find the boat is sluggish when moving above the speed of around 8 knots and then over-revs  (35-40k rpm) without accelerating too much while trying to get on the plane.

It is also hard to drive at speeds from 10-20 knots. 

Eventually it seems to engage and manages to get on the plane where it drives nicely (30+knts). 

Do you think this is prop related or something else? 

The hulls were originally owned by Yamaha so I dont think that it would be an issue with the length of the leg but i could be wrong. 

Any ideas? 


Posts: 4050

Date Joined: 01/02/10

 Sounds like a bit of

Tue, 2020-02-18 20:10

 Sounds like a bit of cavitation. 8-17 knots or so is a bit of no mans land for boat speed. Too fast for putting around but too slow for a clean plane. 


Does anyone know where the love of god goes, when the waves turn the minutes to hours?

Posts: 281

Date Joined: 28/11/16

Are you trimmed all the way

Tue, 2020-02-18 20:47

Are you trimmed all the way down when getting onto plane? Or too much weight aft? Maybe prop hub spinning however I wouldn’t believe so being able to get onto plane 

sea-kem's picture

Posts: 12074

Date Joined: 30/11/09

 Definitely cavitation issue,

Tue, 2020-02-18 20:48

 Definitely cavitation issue, prop change and all else fails a set of wings will get it up on the plane.


Love the West!

Faulkner Family's picture

Posts: 15622

Date Joined: 11/03/08

 Try playing around with the

Wed, 2020-02-19 05:32

 Try playing around with the trim levels. I did that with my boat until I found the sweet spot. 


RUSS and SANDY. A family that fishes together stays together

Posts: 346

Date Joined: 17/07/07

check motor hieght

Wed, 2020-02-19 06:16

 before you hit the water next time check the motor hieght on the transom

as a general rule of thumb the cavitation plate on the motor should be in line

with the bottom of the keel. if it`s too high you will get a lot of cavitiation.

Posts: 536

Date Joined: 21/05/12

if its a second hand boat -

Wed, 2020-02-19 06:17

if its a second hand boat - would expect the prop would be the right size

i m sure u would have trimmed it in and out by now

u might have spun the rubber bushing  in the prop - it will get worse as time goes by till it only does about 5-6 kn

just for interest look up cavitation vs aeration - it wont be cavitation


i have a spare prop - would be a  bit course for your boat - but would straight away tell u if it is the rubber

 i m about 5 mins from a ramp - if u wanna bring the rig down we can chuck a prop on and go test it - will take about 30 minutes

in rocko

if u are NOR  take the prop to Solas in o/park -they should eb able to check the rubber bushing- and they can push in new bushing

brown364's picture

Posts: 185

Date Joined: 25/08/15


Fri, 2020-02-21 06:57

 Issue with the thunderbird with a 115 salty on it. I will follow this one and try the above mentioned to see if this makes a differance aswell. thanks for the input peeps.