1986 Honda 200sx Need help

[Marcelo]

I have a problem with my 1986 honda 200sx. It idles good, but for some reason ittle start revving high. It also drives by itslef when it does that. It also wastes a lot if gas, but im more worried about the iding issue. I have the idle low right now so it wouldnt do that, but when i fix the idle, it idles good, but itll start revving up. Please help me

[Mech]

Hi. How long has it been doing this, and did you do anything to it before it started doing this ?

And are you saying it sits there idling at the right speed for a while, then starts revving by itself ?

You should check it doesn't have air leaks between the carby and the head, and probably clean the carby and then check it's idle mixture adjustment.

[Marcelo]

Its been doing it since i got it. I have the idle low so it doesnt do it. And yea it just starts revving up. Its its in gear, it starts driving by itself. Ill check the carb and the idle. Thanks

[MarkinAR]

I've seen that a few times and most times it's a vacuum leak between the carb and head, normally a gasket or oring not sealing properly. Alternatively, i've seen that happen also as a result of a sticky throttle butterfly in the carb or sticky throttle cable.

[Marcelo]

Alright, will check that out. Thanks