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Re: Tiny might propeller slip

Posted: Sun Oct 13, 2019 11:40 am
by kens
Whoaaa, NO, no.
You size the prop such that WOT rpm is held in check by prop size.
you have a too small a prop right now.
you need bigger prop not smaller;
if the engine is rated at 6000rpm, then you size the prop such that you do not exceed 6000 because of the size of the prop.

Bill, the clutch should be of enough ability to hold all the engine power.

A prior post said you had a 11x15 prop and 6000rpm. if at that point you were not WOT for fear of over-revving, then that is too small a prop right there.

Re: Tiny might propeller slip

Posted: Mon Nov 18, 2019 9:48 am
by JhlFin
Finally got new strut made, took long enough.

Had litte problems when welded strut, warpped strut housing. First bearing was destryed while installing. Little bit of work and i tought that now it would be good, but not... Second bearin installed, well guess what? too tight :D Well i sanded it a bit and now its ok for testing, just hoping that weather gets bit better.

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Re: Tiny might propeller slip

Posted: Mon Nov 18, 2019 7:52 pm
by kens
Very nice fabrication work.

Re: Tiny might propeller slip

Posted: Fri Nov 22, 2019 8:11 am
by JhlFin
Last testdrive for this season with new strut. New tachometer acted pretty much same as old, need to check wiring. Dont have accurate reading, but max speed was pretty much the same. So strut was not the issue. I feel like front of boat is too heavy or trim tabs were at wrong position. Lots of work to be done in winter, more testing in spring :)

https://youtu.be/cB0GuI2oyY0

Re: Tiny might propeller slip

Posted: Wed Nov 27, 2019 9:12 am
by JhlFin
Im thinking that my prop is not made for high speed/rpm, blades are thick and not even finished properly from what i can tell. i cant find any other suitable props in Finland. I would be very happy if someone could guide me to find and choose right steel prop. I think someone used 10x15 2 blade steel prop with honda 4cyl engine and it was fast, i have heavier engine, but horsepower i can match :) Would 2 blade propeller be better option, or atleast steel 3 blade?