2004 Yamaha 150 four stroke high idle problem

Bronzer

Cadet
Joined
Dec 18, 2016
Messages
14
I just bought a bass boat with a 2004 Yamaha 150 four stroke outboard. It idles around 1200-1300 rpm, and it grinds when I put it in gear. Even once in gear, it idles at the 1200-1300 level. The previous owner says it has been that way the whole time he has owned it. I know it should be around 750 rpm at idle. Is this something that I can adjust or am I going to have to take it to a mechanic?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,128
need to take to a Yamaha shop with a Yamaha master tech if you do not have the knowledge and tools to find the problem.
Something is broke or disconnected

also I would think the lower clutch dogs and gears are not in very good shape if he has been running this thing like that for 12 years
 

wrench 3

Commander
Joined
Aug 12, 2012
Messages
2,108
Check the throttle linkage to make sure that it's returning all the way to the idle position. Also check for vacuum leaks (a hose off etc.)
 
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