2.25l gas engine runs like crap

[Katmai]

The engine in my SWB has a problem and its driving me nuts. It starts great (it normaly starts on one turn of the handcrank), idles like a sewing machine, doesn't smoke, and doesn't use any oil.

The problem is that it lacks top end performance and the gas mileage has become terrible. As late as March of this year it would wind out to 75 mph on the highway in overdrive and got decent gas mileage (for a rover). Now, it will barely do 50mph and it absolutely chugs gas.

I have tried adjusting the timing, have rebuilt the carb, rebuilt the distributor and installed electronic ignition, changed the fuel pump, and installed a new coil. None of it has helped in the slightest.

If I attempt to wind it out in say first gear, the engine accelerates fine to a point and then acts as if its not getting any fuel i.e. the power curve just stops curving upwards and the rpms flatten out.

I am at my wits end and would welcome any advice, no matter how obvious it may seem. I feel as though the problem is something moinor that I've managed to overlook.

Thanks

[tecatetomtj]

Have you checked the timing chain? A worn chain might jump a link or two which can cause a problem like you describe. You mentioned that you changed the fuel pump, so I assume that you also changed the fuel filter, so maybe a kinked fuel line. A simple fuel pressure guage can confirm that you're getting the fuel it needs at higher RPM.