1994 yamaha 70tlrs 2 stroke hard first start.

Joined
Jun 30, 2019
Messages
7
My 70hp outboard I just bought is hard to start the first time of the day then after that it fires up almost instantly when I turn the key. It doesn't seem to have a normal choke system. Could anyone enlighten me on how the choke system works or what I'm doing wrong? I've messed with the fast idol at different speeds and hold the choke button but I don't think it does anything.
 
Joined
Jun 30, 2019
Messages
7
I just fired it up in the driveway and it was idling at 2000 rpm and sputtering a little bit. Do I just need to take the carbs apart and clean them?
 

ThomW

Chief Petty Officer
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Aug 8, 2016
Messages
615
Once its running, does it run fine? Does it bog down? Does it get up to normal WOT RPM's? What is the choke system you have that isn't "normal?" Is the type where you press in the key and hold before starting or something else? You cannot gauge a true idle on the hose, needs back pressure of being in the water. Any old 2-stroke will be a little cold blooded and may start hard at first. If you are somewhat mechanically competent, cleaning the carbs cannot hurt anything. When were they last cleaned?
 
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Jun 30, 2019
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It runs fine wide open or anywhere in between. I'm cleaning the carbs right now. It does not have choke I guess it has what is called prime start.
 
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Jun 30, 2019
Messages
7
Pump the ball till it's hard, turn the key. It has prime start no choke. I was giving it a little throttle but I just cleaned the carbs and it fired right up after with no throttle but still idles high, rpms dropped from 2000 to 1600 and it has a sputter. One of the o rings that goes between the carb and the motor didnt look the best so I ordered a new set, would that cause the sputter? Would it idle lower in the water?
 

flyingscott

Fleet Admiral
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Apr 8, 2014
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7,988
Can you push the key in or is there a toggle under the key? I believe it has a primer that replaces the choke. But it acts the same and must be manually activated. It also has a version of fast start where it will idle higher until it is warmed up.
 
Joined
Jun 30, 2019
Messages
7
I'll try some cold starts the next few days. after rebuilding the carbs and synchronizing the carbs it fires right up and idles around 800 rpm
 
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