2004 90 4 stroke Idle Problems

[JWilder85]

I have a 90 4 stroke, normally it idles around 600-700 rpms, but lately it has been idling around 1000-1200 rpms while in neutral. When I put it into gear its drops a couple hundred as usual. When I crank the engine it revs up alot higher than normal. Anyone have any ideas what might be wrong? It fixed itself one time but the problem has come back.

Josh

[CatCam]

I have the same motor, last of the caubuerated 90's.....there is a idle adjustment screw....at idle, back it down to you are a 700 RPM. When it "fixed" itself maybe you were hitting on 3 cylinders. With these 4 stroke, 4 cy. engines if one of you low spped jets get temporarily clogged the motor still runs pretty smooth...
Post back after you adjust the idle.

[99yam40]

Clean the carbs properly , readjusting will not fix anything

[CatCam]

dirty carbs (low speed jets) shouldn''t make the motor idle high at 1200 RPM! Set idle adjustment screw to 700 RPM.

[99yam40]

once carbs are set up properly they do not have to be reset unless something changes, if it is because something is messed up, fix what has messed up.
running lean will cause RPM to rise , if you have ever run one out of fuel you will notice the rpm rise before it dies

timing advancing can raise RPM also, but have no idea what would cause that unless the CDI is starting to go out as that is what controls it even for the 4 strokes I think.
Test what you can
But just readjusting stuff is not a fix