Yamaha 70 (small lower) Cooling..

Hi,
for those with experience running the small 70CES lower (or the 48/55/60hp 2Cyl lower) on either the 70 or the 2Cyl 55/60hp engines, I'm looking for suggestions:

- run with or without a thermostat? (poppet too, on the 2Cyl)
- use a different tell tail pickup location..? (top of the head on a stock 70 to mimic the CES head?)
- epoxy the top half of the plastic water inlet inserts..?
- custom inserts that "scoop" more water..?
- what kind of pressure numbers should one see (with and/or without thermostat)?


I am not running a nose cone, and low pickups are not allowed. I can only use the inlet location above the prop shaft on the sides of the lower (stock location).
I am currently running both the Yamaha 850cc 70hp and 760CC 55hp 2Cyl, they share the same lowers. Both are on padded v-bottom hulls (Delta and a Voodoo).

cheers,
M

bump.
still looking for opinions.

2 scoops on the hull to shoot water to the stock inlet

Don't think our rules will allow that.

Wondering mostly if people run with fully stock water pickup inserts, without a nose cone, and if they have any issues running the prop shaft high for a surfacing prop on a v-hull (T850)..

Quote:

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Originally Posted by hydrospeed77

Don't think our rules will allow that.

Wondering mostly if people run with fully stock water pickup inserts, without a nose cone, and if they have any issues running the prop shaft high for a surfacing prop on a v-hull (T850)..

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same for any outboard, you raise the engine till you run out of water pressure, then down a bit when you have to run stock

Quote:

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Originally Posted by Powerabout

same for any outboard, you raise the engine till you run out of water pressure, then down a bit when you have to run stock

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Already done that. Also tried both partially blocked inserts and stock inserts. Looking for peoples' opinions on the specifics in my original post. Wanna know what they've found trying various things...

I'm thinking of building some scoop-style inserts.

Interesting that some have said run without thermostat, some have said run with a hotter thermostat... No one has said anything about the poppet valve or mentioned safe pressure/flow/temps..