DIY Aetna Tach Bezels 5" -4"

View attachment 77963
Based on what others have said, I was lucky I guess that my old tachs and sync gauge were fairly accurate. I do not have a synchronizer either so I was never really sure until I put in the Aetnas, but the sync gauge is right on at the lower rpms and off just a tiny bit at wot. Not enough to bother to adjust imo.
Hopefully you’ll be lucky and not have to adjust it also.
Nice WOT numbers there Mark. I'm about 25 rpm less than that but I'm a few tenths of an inch more pitch than you.
 
Thanks, that picture was taken maybe 2 days after I put the tachs in. We were on our way home from Florida and one of the tachs quit so I replaced it while in NY city. That was the first wot check with the new tachs while running up the Hudson. We were loaded down with full tankage for the last leg home, dinghy, and probably not the cleanest bottom.
She’ll do 2725 on 1/2 tanks and clean bottom.
What really was surprising to me was how close they run. Now I REALLY trust my prop guy :)
 
I have no sync gauge, but a switch that engages the sync. The port throttle becomes the slave and both engines are operated with the starboard throttle. Tachs always read with identical RPMs.

Bennett
+1 Like Bennett said, mine works as advertised
 
Thanks, that picture was taken maybe 2 days after I put the tachs in. We were on our way home from Florida and one of the tachs quit so I replaced it while in NY city. That was the first wot check with the new tachs while running up the Hudson. We were loaded down with full tankage for the last leg home, dinghy, and probably not the cleanest bottom.
She’ll do 2725 on 1/2 tanks and clean bottom.
What really was surprising to me was how close they run. Now I REALLY trust my prop guy :)

I just ran mine WOT getting 2720/2725 with fuel at about 1/3 full, full water and just myself onboard. I think this is about 8-9% overpropped. I’m thinking I need to add about 100-125 RPM to get up and over 2800. I usually fill the tanks, and have 6-8 people.

I’m planning to pull the boat this spring and do some bottom work. Opinions on the props/pitch? Tweet them or leave well enough alone.

FA967B3A-7C65-4607-923C-EC39D30ED819.jpeg
 
Dave,

On our 410DA with full fuel, 1/2 water, tabs down, and 2 people we would get 2800 RPM WOT on the Aetna's with freshly tuned 22" x 23" props.

-Tom
 
I just ran mine WOT getting 2720/2725 with fuel at about 1/3 full, full water and just myself onboard. I think this is about 8-9% overpropped. I’m thinking I need to add about 100-125 RPM to get up and over 2800. I usually fill the tanks, and have 6-8 people.

I’m planning to pull the boat this spring and do some bottom work. Opinions on the props/pitch? Tweet them or leave well enough alone.

View attachment 78312
My opinion is fill the fuel full, get your 6 people on board. Then run your WOT test. Then make your decision.
 

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