Optimax problem - Low pressure

[Jimwave]

Hi everybody,

I have an Optimax 200 mod. 11/99. Last summer the engine seemed to work properly. Having full open throttle the max rpm was about 5400 and speed up to 50 mph.
Last week I noticed that even with FOT max rpm was 4700-4800. Besides that problem, the engine is O.K. I checked the engine with a Digital Diagnostic Terminal and no problems were referred. Then I checked the air and fuel pressure. The air pressure was 65 psi and the fuel pressure was 75 psi, well below the acceptable range (80 and 90 psi, respectively).
It is a little bit strange because I have heard that according to the service manual engine will not start if air pressure is below 70 psi.
Several causes were given to me by the Mercury mechanic but nothing for sure. The problem is that among the potential causes fuel pumps and tracker diaphragm were mentioned (quite expensive).
Has anybody experienced a problem like that?

Thanks,

Jim

[Under the Thumb]

Jim,

Have a look here
it sounds like the same thing you're going through. The first Opti's had a few problems and there were some recalls for injector and fuel rail related issues.

Will

[Jimwave]

Thanks Will.

According to my service manual possible causes are, as follows:
- leaks from high pressure air lines
- failure of air compressor reed valves
- faulty air pressure regulator
- faulty tracker diaphragm
Since the fuel pressure is 10 psi over the air pressure I don't think that the problem is from the fuel pumps. Further, I don't think that fuel pressure regulator is damaged.
The problem you mentioned derived from the tracker diaphragm.
I heard that this diapragm goes with the fuel/air rail and costs something like 1500 Euros. So, I hope that my problem is due to air leakage or compressor reeds.