Re: 40 hp Big twin Selectric gearbox questions

[amuller]

quote FrankR:

1. The leads come out of the exhaust housing through the hole where you would normally access the shift rod coupling. Then up along the backside of the exh housing (inside the lower cover) and clamp at the cylinder head. There are rubber sleeves covering the disconnects

Thanks. Found them.

2.Yes, you can check the resistance between each lead and ground. I’d have to get the book out to see what it is supposed to be (4 Ohms???)
Measuring at the conector to the control box, I got 8 ohm in one and 10 in the other. Differences could easily be due to sketchy patch job on wiring.

3. Yes, continuous power is required to hold it in gear

I guess this is why the electric shift units all seem to have had generators? Is there a minimum voltage needed to keep the box engaged? When it drops too low will there be damaging slippage or a clean release?

4. Yes, you can apply 12V to each lead and ground. If running, clutch will engage and prop will turn. If on a stand, clutch will engage and lock the prop in one direction only. You will be able to turn prop in other direction with some drag felt.. WARNING–never apply power to both leads at the same time while running. Something will bust if you do.

Yes, it behaves just like you say, in both directions. The free backwards movement feels like a spring clutch releasing.

5. WRONG. The Hydro=Electric shift defaults to forward. Yours defaults to neutral

6. They actually are pretty reliable. Killers are water in gearcase (rust) and poor electrical connections (rotted wires). Shift switches in the control are hard to get and $$$$

Initial impression: The quality of the electrical stuff is not up to what one needs for a critical circuit in a marine environment. Need tinned wire of larger gauge, higher quality insulation, plated connectors, get rid of the spade terminals, better switch ….. What I see looks marginal for fresh water, probably would not last at all in Florida….

Question: I don’t see any interlock to prevent shifting at open throttle. Am I missing something?

Has anybody come up with a good substitute for the factory switch? Looks like it just needs a single-pole-double-throw, ideally with a delay through center-off.