Motor problem

[BabyHeuy]

I have a 1994 Mercury 200hp XRI motor on a 1994 488vs ranger

Here is the problem

The motor does not seem to have much power initially.
For instance I can not put it on the trailer it will not get the rpms it needs to push the boat on the trailer.

It has a slow slow hole shot, but eventually takes off and will run up to 6000 rpms, but it should only turn about 5800 at WOT.

It seems to pump water ok. I get about 15psi at WOT.
What could cause to not have any power?
With three people in the boat it will not get on plane.

I think it has the right prop. It is a 25p tempest

[CTFSHWHISKER]

could be throttle position sensor,bad plug misfiring at slow speed.

[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"