I recently purchased a 1999 Merc 9.9 2S. First time out it seemed like the carb need adjustment - it would run fine at wot but when you slowed to just before idle it would idle rough and eventually stall. I took the carb apart and cleaned it out then I placed the motor in a barrel and made adjustments to the low speed idle screw. Seemed to run fine in barrel - no stalling.
Took it out tonight and it ran like crap at first - it didn't seem to have as much power as first time out and actually would lose power while at full throttle. Played with idle speed adjustment but only made slight difference. After about 15 minutes of run time it began to run fine again and seemed to do so until it got to dark and had to take it out (maybe 15-20 minutes).
I had previously checked compression several times consistently 105psi in each cyllinder cold and 110 psi warm. Spark appears to be ok as well. Temp of water out of tell-tale stream is 110-115 degrees.
Is it possible that a seal or gasket may be a little loose or worn and self seals once the engine block warms and expands? Can you think of anything else that it may be?
Thanks in advance guys.
Took it out tonight and it ran like crap at first - it didn't seem to have as much power as first time out and actually would lose power while at full throttle. Played with idle speed adjustment but only made slight difference. After about 15 minutes of run time it began to run fine again and seemed to do so until it got to dark and had to take it out (maybe 15-20 minutes).
I had previously checked compression several times consistently 105psi in each cyllinder cold and 110 psi warm. Spark appears to be ok as well. Temp of water out of tell-tale stream is 110-115 degrees.
Is it possible that a seal or gasket may be a little loose or worn and self seals once the engine block warms and expands? Can you think of anything else that it may be?
Thanks in advance guys.
