Assuming the raves aren't actuating the engine won't be able to rev out to upper 6,000's, say 6,800 or so. The raves are part of the tuning of exhaust scavenging and when in normal closed position reduce the size of the exhaust ports to obtain good low speed throttle response.
Once the engine reaches a point additional breathing is necessary to accommodate gas flow the raves open and the exhaust pipe then works as a sort of resonant sonic supercharger, just like the stinger exhaust expansion pipe you probably recall on the old 2-stroke motorcycles.
Occasionally on my 951 one of the raves will gum and stick due to my lack of cleaning them (once or twice/season for my use), causing top speed to fall off considerably. It's not always immediately apparent when just one sticks, but top speed is definitely compromised.
So assuming both raves aren't actuating at all, 45mph might be the limit in your case, that seems plausible.
I believe there's an LED on the solenoid that comes on when the MPEM provides the ground path to energize the solenoid (this produces a 12v drop across the solenoid coil), you should measure 12V at both sides of the solenoid when solenoid is off and 12V only on the feed side while it's being energized by the MPEM. If there's not 12V on the feed side of the solenoid (for whatever reason), there will be no current once the MPEM provides a path to ground energize it.
I typically use a diaper pin to back-probe the connector shell while measuring voltage on the terminal connector pins.
