1999 Mercury 200 EFI

[Chrisried]

I have a 1999 Mercury 200 EFI and it seems to run fine and pushes my 20ft glass boat to 50mph, but the idle seems to be a bit rough and the motor shakes at low RPM's. I have checked the compression and it is 130 on all cylinders,

I replaced the plugs, and checked the wires and found no damage and virtually no resistance. I'm getting spark at all cylinders.

Not sure what else to check, or if these is even an issue as I have seen others say that's just how they run.

Here's a video of the idle

https://youtu.be/I0GXEPpy4ew

 

[wn6ngp]

How does it idle when actually on the water? Does it pick right up and go on a plane? I've got a carbed 90hp version and it idles about the same.on the water so I'd guess its ok. Problem is that we hear these new 4 strokes that sound like a purring toyota camry and its just not a valid comparison.

 

[Chrisried]

It idles the same on the water. It doesn't feel like it has the hole shot that my 19ft spectrum with 120hp force had, but the boat is a foot longer and is glass instead of aluminum. It is good and smooth on the mid to upper RPM range and has plenty of power. Just down low it sounds like a hot rod loping.

 

[Dukedog]

It idles the same on the water. It doesn't feel like it has the hole shot that my 19ft spectrum with 120hp force had, but the boat is a foot longer and is glass instead of aluminum. It is good and smooth on the mid to upper RPM range and has plenty of power. Just down low it sounds like a hot rod loping.

hole shot could be prop/set up...
soundin' like a "dirt tracker" at idle..... normal.