1995 mercury 200hp X Ri please help

Coolbreeze96

Recruit
Joined
Aug 2, 2018
Messages
1
I'm working on a 1995 200hp mercury XRi, it runs great, but anything over 5000rpms after about an 1/8th of mile it falls back to about 4300rpms, doesn't cut off or anything. Now if I bring it back to neutral lay down on it, it will pick up for an 1/8th mile and do it all over again, have changed stator, trigger, coils, basically everything electrical, TPS, changed fuel pressure regulator fuel pump, high and low, changed fuel line bulb and run it from another tank, removed all electrical from battery except engine cables, unhooked voltage regulator, changed ECU cleaned injectors, holds 40psi, removed the oiler, hooked timing light to every cylinder doesn't fall when it drops rpm's, any help would be greatly appreciated please be my hero, lol no one local including myself can fix this thing, if u can point me in a direction I haven't been and fix thus thing u will definitely be the man....lol
 
Joined
Jul 23, 2018
Messages
6
Is the fuel pump diaphram/check valve kit new? Have you replaced fuel primer bulb and all feed line to engine from the fuel cell? Install a clear line between the fuel tank and the fuel primer bulb and look for air bubbles in the fuel which would indicate a fuel restriction. Have you run this engine on a separate remote fuel tank to eliminate the possibility of a fuel tank issue? With a vacuum gauge t"d into the fuel system supply hose you should see no more than 3 inches of vacuum on the gauge.
 
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