225 Merc 1990 carbureted two stroke idles high and surges

[BillyDeeGrady]

The motor was running fine but started idling high at 1000 RPM and surges to 1300 RPM. I suspected a vacum leak but can't find it. The motor starts, it will rev so I am guessing at this point that fuel and ignition are good. Has anyone seen this high idle and surging before?

 

[faztbullet]

Without serial number to confire, but some of the earlier 3L motors had a TPS on carb linkage that could cause this problem

 

[BillyDeeGrady]

Without serial number to confire, but some of the earlier 3L motors had a TPS on carb linkage that could cause this problem

OG243456 which I think is a 1992? I don't see how it has a TPS like a throttle body injected system has. There are electronic components on the starboard side of the moor. Are they adjustable?

 

[BillyDeeGrady]

OG243456 which I think is a 1992? I don't see how it has a TPS like a throttle body injected system has. There are electronic components on the starboard side of the motor. Are they adjustable and they control the carb throttle plates?

 

[faztbullet]

 

[faztbullet]

Here is link to check test and adjust...

http://files.motorka.org/plm/mercury/service_manual/mercury_2t/mercury_225_225EFI_250EFI/2c.pdf

 

[BillyDeeGrady]

Here is link to check test and adjust...

http://files.motorka.org/plm/mercury/service_manual/mercury_2t/mercury_225_225EFI_250EFI/2c.pdf

Wow! Looks like you have it right. Thanks for the lesson and now we can get back on the water. Much appreciated!