Oh boy...not another prop ?

B

BillTex

Junior Member
87 V20, 2000 Johnson 150 Ocean Runner running Solas 15 x 15 alum. Engine was decarbed this spring. Plugs are new.

With just me, full fuel, usual boat/fishing gear (not 'lightly" loaded) I can only get 5k at wot.

Boat cruises 28 mph at 4k burning 8-9 gph.

Tach was verified with timing light. She jumps right up on plane quick. Cruises very nice at 4k with full load (4-5 People).

I'm a fisherman, not a racer, and I am happy with this performance...but shouldn't I be seeing more than 5k with this prop?
I don't want to be lugging engine.

Thoughts?

Tx, Bill
 
5,000 rpms trimmed up to just before loosing bite ......or with motor down ?
What mounting hole you using ?

Should see the cav plate on surface of water when trimmed out and on plane.

Yes, I'd think 5,600 rpm with 15" prop for sure......or more.
 
That is a lower rpm engine. 5500 is it for it, so 5000 isn't that bad(reccomended wot rpm range is 4500-5500). My question is, has it always ran this way? Many times people get there prop rebuilt, and lose speed, they think it was the engine, but in reality it was just the die the prop shop used to reshape the blade. I will say in my opinion, a 15" diameter prop is a large prop for that small v-6 to be turning. It's not always just pitch you need to look at. I would think a smaller diameter prop would get your rpm's up, but chances are you'll lose some bite and mid range performance.
 
Thanks guys, yes I just found specs on-line also 4500-5500 so I am right in the middle of range.
Cavitation plate running at proper depth.

Thanx for the gut check.

Life is good...lovin our V!

Bill
 
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