four stroke 115 loss of power

I recently had my engine serviced and had the injectors cleaned out due to problems from ethanol mixed fuel. Since then i have run the motar and still notice problems with powering up getting the boat on plane. Engine seems to stutter, bog and vibrate. Also i notice that at full throttle the engine would get up to about 5600 rpm but now will top out at a bout 4800. Any ideas? Thanks.

[boats.net]

Try a new set of spark plugs, check to see if have spark on all cylinders. Have injectors rechecked.

Did you have the VST tank and filter cleaned? If the injectors were dirty and needed cleaning then that filter needs it too.

Thanks guys. Could it be a fuel problem also. After servicing i emptied the tank but may have had some old contaminated fuel still in. When they did the servicing and testing they used their own fuel ( not from my tank). IF i still had some water/contaminant in tank could that be causig these problems. What areas should i look at to check. Thanks again for the help.

thanks

Try a new set of spark plugs, check to see if have spark on all cylinders. Have injectors rechecked.

Could it be a fuel problem also. After servicing i emptied the tank but may have had some old contaminated fuel still in. When they did the servicing and testing they used their own fuel ( not from my tank). IF i still had some water/contaminant in tank could that be causig these problems. What areas should i look at to check. Thanks again for the help.

Do you have a water/fuel seperator? If not get one and use the Yamaha or Racor filter. Also check the filter bowl on the back of the engine. Pour it into a glass jar or something and let it settle a few minutes. See if any water seperates from the gas. If so that could be your problem.

[rkmartin]

I would find out exactly what service was done by your mechanic. What parts were replaced...What procedures were performed...etc. This information will give you an idea where to start.