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prop wont spin after 3000 rpm.

S

subman86

New member
I have a Johnson outboard motor 200 hp 1994 vintage. Prop spins until you reach 3000 rpm then you hear a whirling noise and prop won't spin. I was thinking it must be in the transmission. I'm a car guy so this is foreign to me.
 
Is this the prop pushing a boat faster until you reach the 3000 rpms. Then the the engine suddenly speeds up but the prop stops pushing & the boat slows down ?
 
Has the prop ever hit anything while running ? Do you know if it is a correct prop for the engine ? Is this a sudden problem on a engine that ran with no problems /
 
it is a sudden problem. ran fine previously. im checking with my cousin on the condition of the prop as this is his boat that im helping with.
 
i did ask him about the engine rpm increasing and if the boat speed slowed down at the same time. i will get back to you. what type of drive line connects the prop to the engine. is there any sort of transmission? or is it connected and a 1:1 ratio always
 
Quick guess is a slipping drive hub between the prop shaft & the prop. Not sure if the prop has a hub ventilator ring, that may be gone.

so many items to check some times

Has he raised the prop up in the air & seen if the prop is covered with tough weeds ?
 
racerone said:
try another prop.----Sounds like the rubber drive hub is slipping inside the prop.
Click to expand...
he has removed the boat from water and didn't see anything obvious on the prop. he said it will run below 2800 rpms but if you try to go above it gets real loud and rpms jump and you lose all thrust. if you bring it back to neutral engine it works again. i heart someone mention possible cavitation issue. is the drive hub what is between the prop and the prop shaft or... i couldn't find a decent picture of it
 
O K guys. :)

Tell him about prop height / clearence below the bottom of the boat. Motor angles with a person in the boat when viewed from the side
Lets hope for a simple fix.
 
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