Yamaha F70 overheat after 40 hours

cv1057

Recruit
Joined
May 1, 2013
Messages
1
Have a 2010 F70A 4 stroke bought new with boat, and overheated. Replaced all oils and filters, gaped plugs, and replaced Impeller, with all Yamaha parts. Worked fine and only 5 hours more on motor and doing it again. I never run full throttle Anyone have any ideas what can be causing this?:confused:
 

Capt Ken

Commander
Joined
Jul 30, 2002
Messages
2,269
Re: Yamaha F70 overheat after 40 hours

Sounds like a possible thermostat not opening or pressure valve sticking open.
 
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