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Prop change

R

Randym

New member
I changed the prop on my Honda 50 HP 4 stroke and the RPM's have decreased but the boat speed is about the same. The new RPM's are about 3200 vs 4000+ on original prop. The replacement prop is after market but was listed for a Honda 50. Should I be concerned? I recently did a 60 mile trip with no adverse operation.
 
hi you seem to have bought a bigger pitch prop it should be fine. a bit quieter I imagine and you might get a bit better fuel economy. Did you check the pitch difference between your 2 props? it should have it on the back side.
 
If 4000 rpm is your rpm at full throttle and trimmed out, that is not enough. The 50 should be propped to run at between 5000 and 5500 rpm....with the emphasis for the rpm's to be closer to 5500.

If the 4000 rpm is at full throttle, it is like trying to go up a steep hill in your stick shift car in 4th gear. You will probably make it, but the engine is struggling.

For best engine life and efficiency, it needs to be propped at the proper rpm.

Mike
 
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