New Motor for CP23

[lochinvar]

Been busy and have bought two motors, one for my CP19 being refirbished and one for the CP23 I am picking up in Oklahoma in a couple of weeks.

I was originally going to use the 6hp tohatsu on the CP23 but found a really good deal on another tohatsu.

It is a Tohatsu 8 hp longshaft and it is so much smoother than the 6hp. Has anyone run this motor? I bought the charging coil and voltage regulator to put on it as well.



I added the Solas 4-blade high-thrust prop. This one does not have a remote control as the 6hp does. Do any of you run the remote control setup on the 23 and how do you like it if so?

[jcatkeson]

I assume that by remote control you mean shifter and throttle being located in the cockpit. I had inquired about one for a Honda and was startled by the price.

[skip1930]

" I added the Solas 4-blade high-thrust prop "

I not sure what 'High Thrust' really means. More blades usually means less pitch.
I have no idea why four blades are fitted to those British Sea Gull two strokes.

Generally;
Four blades are not that efficient when compared to three blades. The fourth blade is in the way. At 1000 rpm that is 4000 pulses a minute.
Three blades are the most efficient to produce that desired helix. At 1000 rpm that is 3000 pulses a minute.
Two blades are even more efficient then three blades. But two blades are usually too large in diameter.
And of course a single blade is the most efficient but can't be balanced.

Side bar; On some record setting ultra high speed U-Control model aeroplanes use a single blade prop with a big lump at the other end.
But your talking a circle 50 foot [?] and 200+ mph at 22,000 rpm on nitro.

skip.

[Shawn]

"I not sure what 'High Thrust' really means. More blades usually means less pitch. "

That is the whole point. A lower pitch propeller gives higher thrust...  the HP of the engine is trying to push a smaller amount of water. The trade off is the expensive of top speed.

"I have no idea why four blades are fitted to those British Sea Gull two strokes."

Their highest thrust models had 5 blades. The reason it had that is because it was geared to be a very slow moving propeller compared to what is on an engine designed for a planning hull.



"Side bar; On some record setting ultra high speed U-Control model aeroplanes use a single blade prop with a big lump at the other end."

That is completely the opposite of what is needed for a sailboat. Design of a propeller is different for high speed operation compared to low speed as used on a displacement hull.

Shawn