Merc 150 Won't stay at full throttle

T

TMRKARRING

Recruit
Joined
Jul 17, 2010
Messages
1
I just bought an old (1980) Merc 150. It starts, idles and runs fine, but when I put it to full throttle, it will drop back to non-planing speed as soon as I release the throttle. Yes, the lever physically moves back and the engine slows down. Am I looking for something on the engine causing this, or is it going to be in the throttle housing? Any insights would be great.

Tim
 
Gomer50

Gomer50

Chief Petty Officer
Joined
Sep 5, 2009
Messages
507
Re: Merc 150 Won't stay at full throttle

Its supposed to, thats the way it is..
 
mxzeatr

mxzeatr

Petty Officer 2nd Class
Joined
Jun 2, 2010
Messages
188
Re: Merc 150 Won't stay at full throttle

You can increase the friction in the control housing to help with that. However you don't want to make it stay whereever you put it in my opinion. I was told that when at speed you should have one hand on throttle and one hand on steering wheel at ALL times. Therefore you hold the throttle where you want it when up there. Just my .02.
 
Superjetjim

Superjetjim

Petty Officer 1st Class
Joined
Jun 5, 2010
Messages
217
Re: Merc 150 Won't stay at full throttle

I have the same rig as you (although 81 which I assume is the same) and it drops off when you release the gas - annoying IMHO. I will be looking at a way to tighten up the throttle.

Jim
 
V

verado7

Chief Petty Officer
Joined
Apr 28, 2009
Messages
511
Re: Merc 150 Won't stay at full throttle

usually at the front of the control box there is a knob you can tighten to fix that .
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,137
Re: Merc 150 Won't stay at full throttle

Tim, That is a sign of good or new control cables. As far as I know, Merc never had any friction control device, so you will need to live with it, until the controls corrode or get dirty.

BTW - The throttle is supposed to stay at whatever setting you place it. While it is smart to keep a hand on the throttle if you are driving a performance boat, that isn't necessary on most boats.
 
You must log in or register to reply here.
Top