1900 sr2 4.3L high rpm problem

[pip]

Hello everybody, i just bought a 1900 sr2.
And i am new to boating :-)

I have some problems with speed and high rpm.
The engine runs smoothly and the last owner claims his top speed was around 55-60 mph just a couple of weeks ago.

But I can only get it up to around 40-42mph WOT running 4800- 5000 rpm i have played a lot with the trimming but i only get 2 mph out of it = 42mph.

And of course im not running WOT more than a couple of minutes ;-)

25mph = 3200-3500 rpm

I think my holeshot is decent but doing a lot of rpms approx 3500- 4000 before it settles down. (without me knowing if thats okay)

Some specs.

1900 sr2 Anniversary edition 1996 or 1997 can't remember
Mercruiser 4.3lx gen+
Alpha drive one gen - Gear ratio 1.81
Quiksilver mirage stainless steel prop - pitch 23 with 3 blades

Any suggestions is appreciated :-)

[mmwjr]

Welcome aboard

WOT for this engine is 4400-4800 so you are a little high.

Did you witness this 60 mph speed yourself? Seems high to me. Where are you boating? Ocean, river, lake and what are the water conditions. Also how many people and gear weight?

[pip]

Thank you!

No i didn't witness it myself i was googling and found that this boats top speed is approx 50mph depending on the prop, gear ratio etc with the 4.3 engine. It doesn't matter for me if it can sail 60 mph. but it would be nice to have it close to the 48-50's

Im boating i Denmark near Copenhagen.
To people each 85kg (187 lb) no waves, salt water, gear weight only some life jackets and a wet carpet not soaked it was raining in the morning that day but sunny when we were sailing.

[mmwjr]

I would think you should get closer to 50 mph, did you try running against and with the current? Going up one size in prop pitch should get you closer.