Chris, I'm puzzeled a bit that you can only reach 5500 RPM with a 19 pitch prop. Even loaded fully you should eaisly reach 58-5900 RPM with that prop. I'm no tech expert or mechanic but this situation would cause me to question if the mechnical throttle linkage on your rig is somehow adjusted a little short of a full open mechanical operation- if that makes sense to you?
I'm not certain what year model these instructions apply to so I'm not suggesting that you try to adjust anything here. these instructions below may not apply to you- but it may help you understand what I'm talking about - especially if you have the hotfoot or foot control throttle installed in your boat?
Copied from a thread in "Bass Resources" website:
Many have asked about how to adjust the throttle-cable and/or hotfoot:
1. Disconnect throttle cable from Anchor point at engine.
2. Confirm that engine can reach WOT by MANUALLY operating the throttle arm on side of engine.
3. Adjust throttle cable so that it holds ENGINE throttle arm FIMRLY against the IDLE STOP
4. Connect cable with attachment nut, snugging the nut down. BACK NUT OFF 3/4 turn (the black plastic washer should spin freely under the nut).
5. On the hotfoot, loosen jam nut for the WOT stop screw, and turn the screw WELL AWAY from the pedal.
6. Depress hotfoot to WOT position- have someone check to ensure WOT was reached at engine. HOLD HOTFOOT HERE.
7. Turn stop screw COUNTECLOCKWISE until it just contacts the pedal (pedal still at WOT position). Release pedal.
8. Turn stop screw 1/2 to ONE TURN FURTHER counterclockwise- hold it in place, and tighten the jam nut (this step helps to prevent throttle cable stretching).
9. Depress hotfoot firmly to WOT position. Verify engine reaching wide open throttle.
