Motor problem

[Barry]

reeds or compression? I would check compression first to see what youv'e got.

[WEBBY]

The engine you have is a 2.5 liter model and a good dependable piece at that. I suggest that you take a look at a few items. 1st I would look at the easy things- like teh check valve in the fuel primer bulb. If this problem exists- it will not allow the engine to have adequate power through the fuel pump delivery system,allowing for a drop in power. Secondly, I would suggest that you take a look at the filters in and near teh VST pump/fuel system.(Large Aluminum casing) on side of engine. This could be a situation of a clogged filter. In most cases not, but you can check. 3rd, I would suggest that you look at the connections near the coil pack as well as the plug wires. Intermentant firing will cause this as well...next go to the spark plug itself. The plug for the engine is a NGK BU8H. Use this plug only and remember to always use Mercury Quickleen in the fuel system to ensure you maintenance your injectors...which I will also say may cause the problem. I always say to maintenance injectors to ensure they are flowing correctly. An injector that is leining out a cyl will pop an engine very quickly. Check the Battery connection to ensure that you have a constant 12 Volts...this EFI will not run properly below this voltage and finally- propeller...make sure your propeller does not have a cracked or broken composite hub insert...this is a very very common instance. Glad to have been a service to you. Please feel free to contact me anytime with questions 859-509-6660...John "Marine Works"