Dust in intake

[3ric]

I have a 2012 Mercury 115 efi that I bought used. The motor idles rough. As I am becoming more familiar with the motor, I noticed it has a dust oil build up inside the intake. The motor came from west Texas. I wiped out the throttle body and cleaned the IAC valve. I also wiped the MAP sensor (I was not brave enough to squirt electrical cleaner in the hole). All of this improves the idle, but it still runs a bit rough. It’s probably also worth mentioning that when I got the motor, the fuel was very bad, so it had been sitting for awhile. But I have also replaced all the fuel lines and filters etc.

In looking at the schematic, there does not seem to be much to the intake. I am mechanically inclined and have tools. Can someone talk me out of taking it all off and cleaning it out? I looks like I would just be out the cost of some gaskets where the intake meets the reeds. Thoughts?

 

[racerone]

Is this a 2 stroke OPTIMAX ?-----Post actual compression test values here.

 

[Faztbullet]

Compression and leak down test needed

 

[3ric]

Sorry everyone I thought this post didn’t post. The compression results were, from the top down 232, 223, 231, 229. (Which seems crazy high, right?). Note, I did gain the confidence to squirt the electrical cleaner into the map sensor. It seemed to help. It’s certainly not as smooth as my buddy’s 2021 75 hp merc, but not too bad anymore. But the perfectionist in me wonders if the cleaning would make it smoother somehow

 

[3ric]

Compression and leak down test needed

I don’t have the ability to do a leak down test. Based on the improvement from the map sensor cleaning you think it would be worth taking it in to have it done?

 

[3ric]

Is this a 2 stroke OPTIMAX ?-----Post actual compression test values here.

No, 4 stroke, sorry should have said that I. The original post

 

[Faztbullet]

Dust inside cowling is: A) transporting on a dirt road or B) dirtdabber nest ground up by flywheel. Have rebuild several engine due to these insects