Very High RPM's after Carb Rebuild

[MeanyMan]

Hi everyone...been a few years since I've been in this forum, but my health is much better and I'm ready to hit the water. I have a 2003 Mercury 50 HP 2 Stroke. She has been sitting in my back yard for a couple of years due to health issues. So recently, I saw that I had a lot of work to do to get her running again. I pulled and rebuild/Clean all 3 carbs. Replaced the floats too as they were in sad shape. Got the kit for all 3 carbs. Also many of the fuel lines that are scattered all over the motor were dry rotted, so I replaced every fuel line and it was hard finding them too as they were all different diameters. I also added a fuel/water separator and purged the gas tank.
Now after all that and putting back together, I fired it up and like "what the hell"......RPM's was 2800 - 3200 like if I had WOT and a little "cough" every once in a while and that was in neutral.
I let it stay running until I finished checking all my fuel line connections that I replaced to ensure no fuel leaks. Didn't see any, so I shut her down and looked all over the engine to see if I did something wrong. Didn't find anything, so now I am lost. Any suggestions are greatly appreciated.

 

[jimmbo]

Are the carbs fully closed? Perhaps when you reinstalled the carbs something is holding one or more of them open. Another thing to check is that the timing is able to retard, as that is what normally controls the idle speed. Did you adjust any screws/bolts on the throttle linkage?

 

[MeanyMan]

Thanks for the reply jimmbo.....Not sure if they are closed or not, but I will check in the morning by taking of the air breather. I did not adjust any screws or linkage when I cleaned them and re-installed them. The timing, I will check that also. Again, thanks for the info, at least it get me looking at other things.

 

[MeanyMan]

Hey jimmbo.....update: Looks like I finally got her running good. Problem was "operator head space".....:laugh:.....For the past few months I have been in pain with my back and hip. So being on meds and working on things like this is not a good idea. If it wasn't for my wife, I would never have figured it out. She saw how ticked I was working on the boat. She told me to take it easy and don't over do it. She said to do what I always do when I work on something.
So I sat back, took out the manual and started to read everything over. The biggest mistake I did was that I didn't pay attention when I reassemble the carbs. I put new floats in the carbs but neglected to bend the taps on the float and check for correct setting (measurement). Bend all of them and check and double checked my measurements and put it all back together and started right up. Ran really good. Still think it needs a little adjustment and my tachometer is not working correctly. So now I have to replace it. No matter how the RPM's are, the tachometer stays on 1200. Now to find the correct tachometer for my pontoon.
Greatly appreciate the help.