Expected revs?

[Dry Run]

Hi,

Anyone know what sort of max revs I should get from a Yamaha 150 HPDI?

Cheers

Steve

[simonl]

I never take mine past 5200

[Dry Run]

Cheers for that

[Pikey Dave]

Originally Posted by Dry Run

Cheers for that

You still need to be able to achieve max WOT rpm though. What is the max RPM for that engine?

[wellhouse]

Originally Posted by Pikey Dave

You still need to be able to achieve max WOT rpm though. What is the max RPM for that engine?

officially yamaha quote WOT as 4500-5500 depending on prop/hull type, bear in mind the newest ones will be 13-14 years old now so like anything getting on a bit, i wouldn't expect it to be like a new engine unless it has been rebuilt. Depending on prop, anything over 4500 is fine, 4800 to 5200 is probably on the limit of expectations at that age on a 15 to 17 inch pitch prop but hull shape/weight/engine height will have an effect.

[simonl]

This prompted me to rev the tits off mine today briefly & note the max revs. It did actually go up to 5400, with a 19" prop. It still sounded sweet but I didn't stay there for long..

[wellhouse]

Originally Posted by simonl

This prompted me to rev the tits off mine today briefly & note the max revs. It did actually go up to 5400, with a 19" prop. It still sounded sweet but I didn't stay there for long..

sounds about right on a 5.5m ish ski boat. Your boat is a bit smaller/lighter/streamlined than 'Dry Runs' ribtec (?) so you will get a few more revs as the engine doesn't have so much to push along. (power to weight ratio versus waterline length and drag). Once you are up to 7-8m rib and approx 1.5 ton you need to run a 15-17 pitch and will loose a few revs with the 150hp. Yours looks good though.