1973 23' cc with bracket performance??

[BigLew]

If your cavitation plate is "on" the water while on plane, then I would bet you have a partial obstruction in you cooling system or a bad water pump/impeller. It sounds like when you need all the cooling you can get is when you have problems and the most significant contributor to cooling capacity is flow volume. Something is retarding your flow volume from achieving max flow. It could also be a bad/wrong thermastat; either not opening enough or something. Depending on the history of the engine, you might want to flush it with a salt/corrosion removal product/solution. If if hasn't been flushed in some time or stored open to entry of bugs, mice, etc., something could have gotten in and made themselves at home and something still in in hte system restricting the flow.

Just my 2 cents.

[Old'sCool]

I saw your boat today at Morris Is. I have a Yam. 250 on alum. bracket and might be able to help out. [email protected]

[travisrandall]

Yeah we saw you also, Reelescape, Great looking rig on the water. I removed the thermostats today. Might be able to water test wed. I put a new impeller in last week, just never seems to get much pressure. only about 5-6 psi on a new gauge.

[Bigshrimpin]

I have tried many different props, i can turn a 19 high enough but i dont get anymore speed than a 17 mirage. whenever i hit 33-34 mph the motor isnt getting enough water, the guage bounces around and eventually runs hot. I have the 225 merc mounted as low as possible on the bracket and it is in the water when on plane. do any of you guys have a 23' with bracket? and where are things positioned? i know i can get more than 35 mph out of her but not with heat issues.

Tbag - You gotta fix the motor overheat issue before you play with props. You can check the cavitation plate and make sure it's at least 3" - 5" up from the bottom of the boat (b/c of 30" setback). assuming that fine . . . start addressing the problem by replacing the water pump (impeller and housing) just to be safe . . . and see if that take care of the overheating problem. If you don't feel comfortable doing it yourself then find someone to look over the engine (check compession or do a leakdown test, clean carbs (if it's not an EFI), check plugs for lean condition (ashy color), Etc. You get the idea . . . once you think the motor is running well . . . you can mess with props.

[riptide]

I have a 3liter 225 Merc on my Sceptre with a Mirage plus 15" pitch prop. It jumps right up on plane and tops out at 42 mph at 5500 rpm.

[bbh57]

Armstrong only recomends 2 1/2 of lift on a 30" setback

[thehermit]

Well...recently I have studied this TOPIC quite a bit.

[travisrandall]

The motor was running on a 19' center console a week before and @6000 had no heat issues. I measured/eyeballed with a level and tape from the bottom of the hull to the top of the bracket and its about 25". might be too high, but when you take a straight edge from the hull bottom the cavitation/aeration plate is 3.5-4" above hull line. I have been trying to push a 21" prop and I know it is slipping like crazy maybe making too much turbulence and disturbing water flow. Im going to try a 15" prop and see what happens.