04' 40 hp yamaha power loss and dies

mojolandry

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Jul 2, 2012
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4
running full throttle, motor losses power and dies. tried to crank, and acted like dead battery. let sit for a few minutes and it cranked up. at full throttle but half the power and then died again. then repeated above. any suggestions?
 

99yam40

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Sep 7, 2008
Messages
8,851
Re: 04' 40 hp yamaha power loss and dies

Sounds like motor is binding up.
Need to check compression to see if you have damaged pistons and cylinders
 

mojolandry

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Jul 2, 2012
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Re: 04' 40 hp yamaha power loss and dies

so that would cause it not to crank right away?
 

99yam40

Fleet Admiral
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Messages
8,851
Re: 04' 40 hp yamaha power loss and dies

Can not turn a motor over means to me it locked up from mechanical binding, either pistons are locking up in cylinders or maybe the lower unit is locking up and the drive shaft will not let motor turn. After cooling off it loosens up.
Either way it does not sound good, but you need to test and inspect things to see what the problem is.

Do not keep running it
 

mojolandry

Recruit
Joined
Jul 2, 2012
Messages
4
Re: 04' 40 hp yamaha power loss and dies

the mechanic said that all 3 pistons were scared and would cost $1800 to $2000 to fix.

I have 2 questions for you and would like your opinion please:
1. Is it worth fixing?
2. Is this something I can do myself?

2004 40hp yamaha 2 stroke.


thanks ahead for your help.
 
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