1995 90hp Mariner #1 CYL not working

[NORIBOR]

Motor sat for over 2yr cleaned carbs and replaced impellar. Engine runs but surges, and backfires in upper RPM's. Compression good replaced plugs Found #1 Cyl not changing performance when plug lead is removed. Misted fuel in carbs has the same effect in all carbs with or without plug lead being connected. Also checked #1 reed valve looks good. swapped plugs, leads, then coils nothing. Ohmed trigger leads checked good. Attempted to T/S switch box and every time I get my meter close to the running engine it goes crazy registering voltage, I step 5 feet away and everything is normal. Any Ideas? Merc by phone says switch box.$$

 

[brandonlegault]

Re: 1995 90hp Mariner #1 CYL not working

Did you find your problem? This sounds all too familiar. Mine is a 1995 merc 90 horse. please let me know.

 

[dilligafda]

Re: 1995 90hp Mariner #1 CYL not working

Surges and backfires at WOT? Sounds like there is an air leak in the engine somewhere. When you cleaned the carbs, did you replace the mounting gaskets? with the engine running, try to spray some carb cleaner around the carb mounting surface, crancase split line and fuel pump mounting surface. If you notice a change in running quality, you have found your problem!<br /><br />Good luck!