Not a spun prop

[Bdugg1522]

I hit a sandbar last week not going very fast maybe 5 to 8 mph. I have a 25hp 2stroke yamaha. I took it to a prop guy and he said its not a spun prop... IF i give it some throttle it will go 3 or 4 mph. When I give it more gas the speed does not change but the engine RPM's so go up. No skipping or crazy sounds from the motor. Any suggestions???

BD

[bumperfood]

Put it in reverse, if it still has no thrust, go back to your prop man and get a known to be good prop to try. If that doesn't help, either something in the bottom end is broken or you may have stripped the splines in the crankshaft or driveshaft.

[robert graham]

Put that prop back on the motor, mark the prop and the hub with a Magic Marker, then run the motor until the problem occurs, then check prop and hub to see if the 2 marks still line up...then you'll know if it's spun or not....my guess is that it's spun. Good Luck!

[Bdugg1522]

I hope it is a spun prop. I filled a garbage can and ran the motor for 30 seconds, and nothing happened (marks still line up). I think I am going to run it in the river this weekend and see what happens under the load of the boat. I also have a new prop that I will try this weekend as well.

Thanks for you input.

[rodbolt17]

well lets take some logic scotty.
if you spun the crank/driveshaft splines the symtoms would be it wont do anything and it wont pee water and it over heats rapidly.
if you shattered a pinion or fwd gear or broke a prop shaft it would pump water but not go anywhere.
my bet is on a spun hub.
metal to metal mechanical failures simply quit.
that rubber can slip as load increases.

[Bdugg1522]

Ok, prop was spun, easy fix. new prop and now a repaired backup...
Thanks for the prop help...

Next problem yamaha 2006 25 ELR
Can only start by pulling the cord. When I try the key it gives a very faint click click. About 2 months ago this started to happen, but would work every other try. Now not at all, I need to pull start each time? Electric starter gone bad?

[99yam40]

bad battery, battery connections, cables, or start relay would be my guess.
Voltmeter attached to different points while turning the key would be best way to find the problem