Alright so I have an old mercury 140hp outboard (inline 6) with a jet. From idle to about half throttle everything works normally. After half throttle the engine will rev up quickly without an increase in thrust. In my opinion this is caused by one (or more) of the following:
1. Sleeve has grooves
2. Improper clearance - needs shimmed
3. Incorrect impeller size and/or pitch
- Is there another possible cause?
Now 1 and 2 I can handle, but 3 is what I need help on. How do you tell what size and pitch you need? Whats the proper method for measuring the impellers I already have? How do you measure diameter, and how do you measure pitch?
And finally, can anyone recommend shops in the valley that would carry sleeves, impellers, shear keys, etc at a decent price? Anchorage as well I suppose.