1990 90HP Mercury motor

" HELP!! I have a 1990 90HP Me

" HELP!! I have a 1990 90HP Mercury motor and when I put her into gear she dosen't have the pickup & go and surges. At wide open she only goes about 25MPH compared to 50+mph. I have changed the plugs, impeller, and cleaned out the fuel filter but she still dose not run like she did.
What could be the problem???
Thanks John "

"John.... Mercurys are not my

"John.... Mercurys are not my line of expertise but it's a good idea to start trouble shooting with the basics.

Check the compression and ignition (spark). The spark should be checked with the s/plugs removed.

If those two areas are as they should be, the most common problem is that the carburetor(s) have become fouled which restricts the fuel flow. This can be tested by simply having the engine running and spraying a fuel mixture into the carburetor(s). If the rpms increase when you do that, the associated carburetor is fouled and will require cleaning.

Joe "

John... I would be checking f

John... I would be checking for a spark (ignition) problem. If this turns out to be the case odds are your stator(if not a red one) has failed. Merc had a stator problem with your model year...DJ