High idle issue during start up warm and cold

[510freak]

Hello fellow boaters. I am new to this forum. I have a 1990 Evinrude V4 100hp VRO engine. When I start my engine it jumps to a very high idle between 1800 to 2000 rpm when it is either cold or warm. I've sprayed carb cleaner around the bottom carburetor and the idle suddenly drops. I've checked all the lines around the carburetor and I have found nothing out of the ordinary from what I can see. Any input would be greatly appreciated. Note all the gaskets on the carburetors are brand new.

 

[rothfm]

Thats alot of RPM at start....That year ( pretty sure) does not have the fast start feature(unless someone has swapped parts from newer years into it?). First think I would look at is to see that the carb plates are actually closed at start when shifter is in neutral. What I'm getting at is Linkage issues holding the carbs and/or timing advance prematurely "wide" or open.

I realize the cleaner is making it drop, but some may be getting into the throats etc....Check linkages/plates and reply back further.

Note, all the lines that "look" ok...Be sure none have tie wraps on them, but good solid tight hose clamps or the original wire clamps.

 

[510freak]

The motor was idling fine and running fine up until a few days ago. We were trying to perform a sync and link with the Seloc manual which I must say is very vague to say the least. The engine model is E100STLESB. Looking at the throttle plates during start the plates are closed completely, and the throttle cam follower or whatever it's called is not touching the throttle linkage assembly when the controls are in neutral. I do have a background in the automotive industry and motorcycle industry so I understand the basics just not the marine side.

 

[510freak]

No Title

Here is my engine. Took off the spark arrester to find A possible vacuum leak