Hi, I have a mercury 9.9hp 2stroke and will not get up to high rpm while in the water.. I can rev it up in neutral and it will rev high but when in forward gear seems to only get up to 2500rpm or so ( just a guess don’t have a tach). I’ve done a lot of work to it but nothing has fixed it, please help with any input on to what I should try next. Here is what’s been done so far:
-ignition wires, sparkplugs replaced
-carb pulled apart and cleaned( nothing replaced but I’m pretty sure I did a good job cleaning and everything looks good)
- then took to outboard shop and they replaced the black box, they said I have no thermostat( previous owner must have pulled it out) they say it’s still off and maybe the exhaust port has carbon build up..but they said it should work... well still not moving very well.
- then I tested stator ohms and 2 readings were off so I thought yes found the problem, replaced stator and now seems to run a little better but still no speed.
compression; both cylinders at 98psi ( not great but should be ok)
- spark is nice and blue and will gap a 3/8 jump.
pull spark plugs off and top cylinder Plug is wet and fouled and bottom is dry and tan coloured
not sure what to do next, seems I don’t have much left to replace and it’s still very sluggish and the guys on kayaks are passing me on the lake.. very very frustrating. Any suggestions of what to try next would be greatly appreciated.
thanks
-ignition wires, sparkplugs replaced
-carb pulled apart and cleaned( nothing replaced but I’m pretty sure I did a good job cleaning and everything looks good)
- then took to outboard shop and they replaced the black box, they said I have no thermostat( previous owner must have pulled it out) they say it’s still off and maybe the exhaust port has carbon build up..but they said it should work... well still not moving very well.
- then I tested stator ohms and 2 readings were off so I thought yes found the problem, replaced stator and now seems to run a little better but still no speed.
compression; both cylinders at 98psi ( not great but should be ok)
- spark is nice and blue and will gap a 3/8 jump.
pull spark plugs off and top cylinder Plug is wet and fouled and bottom is dry and tan coloured
not sure what to do next, seems I don’t have much left to replace and it’s still very sluggish and the guys on kayaks are passing me on the lake.. very very frustrating. Any suggestions of what to try next would be greatly appreciated.
thanks