'95 Yamaha I/O 5.7 overheating

sickofboatsguy

Recruit
Joined
Aug 2, 2010
Messages
3
I have a '95 VIP boat with a 5.7 yamaha. boat over heats when running on muffs or in the lake. Boat runs at normal operating temp when bypassing the outdrive and running on a garden hose hooked into one of the cooling lines. There are no blockages in the outdrive or any of the cooling lines. Water pump appears to be working fine with a new impeller. Any suggestions?
 

Mercnoob

Cadet
Joined
Jun 20, 2010
Messages
18
Re: '95 Yamaha I/O 5.7 overheating

did your impeller fail before? You may have debris in the drive or in the hose coming out causing a blockage. you can hook up a vaccume to the hose leading out of the drive and suck any debris out.
 

sickofboatsguy

Recruit
Joined
Aug 2, 2010
Messages
3
Re: '95 Yamaha I/O 5.7 overheating

Hoses have been flushed and are free of obstructions and the drive was removed, disassembled and re assembled with no obstructions found.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Re: '95 Yamaha I/O 5.7 overheating

Water pump appears to be working fine with a new impeller.

Ayuh,.... How did you determine That,..??
 

sickofboatsguy

Recruit
Joined
Aug 2, 2010
Messages
3
Re: '95 Yamaha I/O 5.7 overheating

it pumps water. It has to be somewhere between the outdrive and the transom.
 
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