Mercury 25xd 1984 idle to middle trottle rough...

[Shile]

I just purchased an Mercury 25xd 1984 ... .. well its more a gift then a purchase...
It starts Ok...idle is Ok..little roughly but from several videos of even newer M25s I realized that its good...
Problem is...from idle to middle throttle is a little rough..then again from middle to WOT its fine...
No smoke..no Pufs its just shaking a little...a little to much for me...
I plan to use some decarbonizer or carburetor cleaner liquid ... (Liqui Moly MTX, we do not have a original SeaFoam that I bump all over Internet)...
I changed plugs (NGK BUHW), cleaned a 25l reservoar, fresh petrol and 50:1 ratio of QuickSilver Premium 2 stroke Oil.
What else to check?

TNX in advance for answers and help

P.S.
Sorry for my spelling, English is not my native language..
Greetings from Croatia...

 

[Dave1027]

Re: Mercury 25xd 1984 idle to middle trottle rough...

Compression test
Lower unit check and fluid change
Fuel pump refurb
carb(s) refurb
Check all fuel lines for cracking/leakage
sync/link

 

[Shile]

Re: Mercury 25xd 1984 idle to middle trottle rough...

Compression test - CHECK
Lower unit check and fluid change - CHECK
Fuel pump refurb - CHECK
carb(s) refurb - CHECK
Check all fuel lines for cracking/leakage - CHECK

sync/link - NO

but I am confused with sync...in my manual it says...full throttle..then to check if mark above lines with 3 dots on flywheel...but??? how the hell I can see dots when flywheel is turning??:facepalm:

Please explain me..

P.S.
I just realized...timing light..its like stroboscop light ... and its pointed to flywheel.Then a dots are visible...

Ok... just report if thats true..TNX