1991 20hp 2 stroke mercury issues

mbalders

Recruit
Joined
Aug 7, 2017
Messages
3
Hi
I have recently purchased a 20hp mercury 2 stroke with pull start. I am a first time boat owner. I had the engine serviced and took it out but i am having problems starting the motor. Runs ok when started and going but just struggles to start and sometimes idles out just after start even when warm. I have changed fuel, checked fuel lines and primer button. Anyone got any ideas how i can fix this.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,293
What do you mean by idles out? Are you turning the primer knob to the right for high idle on cold starts? Describe your cold starting procedure.
 

mbalders

Recruit
Joined
Aug 7, 2017
Messages
3
When i pull the choke out to cold start and it finally kicks over. I leave it in neutral and it chugs for about 20 seconds and then cuts out. It also cuts out sometimes when i go to move out of neutral.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
8,293
That is a primer not a choke, the motor needs to warm up. It sounds more like your cold starting procedure is more of an isue than a motor problem. Try this turn the primer knob all the way to the right. Now pull the primer knob out and start it, when the engine rpms start to slow down push the knob back in. After you push the knob in the engine rpms should start to pick up. When that happens start turning the knob back to the left until it is idling.
 
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