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Help My 1983 Honda Aero idles at max speed!!!

Posted: Mon Feb 09, 2009 11:00 pm
by kaseyjconda32
well i bought a 1983 honda aero and i got it started finally after hours. but it starts hard and when it does warm up it just goes at max speed and the brake is the only way i can get it to idle back down. i seee that the idle screw is missing so i ordered one of them and its on its way. could the throttle be stuck wide open???? what esle could it be so i can get this problem fixed

Posted: Mon Feb 09, 2009 11:46 pm
by steffen707
Well not having an idle screw probably is a big problem. To see if its at WOT, take the air cleaner off and look at the carb opening. When you twist the throttle do you see the piece move up and out of the way to allow more air in?

If so, then its not that your throttle is stuck.

Most likely all caused by that idle screw being gone.

Posted: Tue Feb 10, 2009 12:39 am
by kaseyjconda32
if i put my finger over the whole should it do anything ???

Posted: Tue Feb 10, 2009 3:39 pm
by kaseyjconda32
ok there is a top screw and a middle and a bottom what are each for i am missing the middle and i think thats the idle screw am i right?????????

Screwing Around

Posted: Tue Feb 10, 2009 4:32 pm
by Wheelman-111
Greetings:

If you're running the stock PA04 model 14mm Keihin carb:

The lowermost screw is the float bowl drain. It has an o-ring hidden behind and needs to be tightened down firmly.

The middle screw controls the idle mixture. There should be a spring behind it, but the spring and most of the screw is normally hidden within the carb body. Some people contend that there is also supposed to be a tiny washer behind the screw on some models. None on my 1987 Aero. That screw is to be seated lightly, then turned 1-1/2 to 2 full turns out as a starting point for idle mixture adjustment. Is this the one you're missing? If so you're running a very lean idle mixture and this could be destructive.

The uppermost screw has a phillips/flat round head that protrudes quite a bit away from the carb body. There is a visible spring behind the head. This is the throttle stop and serves to set idle speed, not the mixture as noted above. It simply keeps the throttle slide from closing all the way. It can be turned with a gloved hand.

My Aero had sat with a full tank of fuel for 7 years. The throttle slide was absolutely epoxied to the bore, needing to be dipped for several days in carb cleaner just to get it to budge without breaking the carb in half. I suspect something like that is preventing your throttle slide from closing.

Posted: Tue Feb 17, 2009 9:13 pm
by Salvatore
I had the same problem with the aero i bought and i had to do exactly what Wheelman explained above. I havent soaked it in carb cleaner yet because it seeemed like everything was working fine. Maybe i will do that once i get the rest of the scooter back together. I would wait untill you get the screw and see what that does before you take the whole thing apart.
Good Luck,
Sal