All this time it was the damn tach

[Marsh Skeeter]

So the story goes like this. 2017 Bluewave Purebay 2000 bay boat w/ 175 Suzuki. First prop was a 16x21.5 Suzuki prop. Could hit 6100 rpm, 42ish mph. Swapped props to a 16 x23 pretty much no change. Suspected the tach might be off, but check out okay with a few simple test. Tried another prop 15.5 x25 Scorpion and it showed me that the tach was off badly.

So, got a new tach, 4 people, full of gas, very decent load. WOT 5800 rpm, 50.2 gps.

I should add that the tach was close to 1000 revs off

Glad that is over with. It was really frustrating because if you've ran boats you know the two most important gauges are your tach and water pressure.

[eliteangler]

That is why I ordered the C10 gauge. It is getting it's RPM off of the ECM. Much more reliable source for RPM. I can see how that would have been very frustrating for you. Glad you finally got it narrowed down.

[billnorman1]

You're talking about the Suzuki tach being 1000+- RPM off?

[Marsh Skeeter]

You're talking about the Suzuki tach being 1000+- RPM off?

Yes. Technically it was a Faria tach made for Bluewave.