Honda 20hp

[CHRIBS]

Hi all I have bought a second hand sib with a Honda 20hp outboard, it starts without problem every time but when I’m on full throttle it sounds like it’s been knocked into neutral and revs high, as soon as I ease of the gas it recovers and is fine but I can’t run at full speed as it keeps doing this .....any ideas ?? Thanks

[Poly]

Slipping prop hub?

[CHRIBS]

I’ve just googled it and the videos do sound like what I have ...what’s the solution ?

[Gazzago]

Search for ventilating propellor or ventilation and you should find some answers. Mine does it sometimes under some conditions too.

[Poly]

Originally Posted by CHRIBS

I’ve just googled it and the videos do sound like what I have ...what’s the solution ?

Test it first of all by marking the prop across the hub (tipex is sometimes suggested) and taking it for a spin. If when you come back the mark is no longer one continuous line then the centre of the prop and the outside are rotating at different rates some of the time. You need a new prop or to get that prop reconditioned by a specialist (a new prop is roughly £100, a repair including shipping is probably not going to give you much change from 50).