New Prop

[robeward]

So did a little damage to my prop(like broke it). Got a new one that based on the numbers is exactly the same as the one that was broke.

With old prop-
Speed 30mph @ ~5000RPM

With new prop-
Speed 30mph @ ~5500-5600RPM

Should I be concerned? I will double check but I think the manual says the max normal operating range of my engine is 5000RPM. The old prop is the one that came on the boat which I bought used and is aluminum.

Engine
1998 50hp Johnson 2-stroke 2-cyl
Mod# J50TSLECC
Boat=15.5ft Hydra Sports Bass Boat (fiberglass)

Thanks in advance!

 

[robeward]

Re: New Prop

btt...posted late

 

[robeward]

Re: New Prop

Don't know the numbers on my prop but I can get them if it will help.
Thanks

 

[steelespike]

Re: New Prop

Max rpm is 5,500. Props results will vary brand to brand,model to model.
Number on the props will help.See if you can find the actual demensions
_ _ X _ _. on the barrel or under the prop nut. With todays doctored fuels your motor will be happier at 5,500- 5600.How does the hole shot compare? You might try to check your speed by gps.
I think on a bass boat type a little more speed might be possiuble.

 

[robeward]

Re: New Prop

Thanks. I will call my dad and get the number. I think the hole shot is better and it seems to pull straighter with less steering torque. The engine sounds like a champ at the higher RPM but I just wanted another opinion. Doesn't seem to burn that much more gas although still not positive yet.

 

[steelespike]

Re: New Prop

The motor will still burn about the same amount at wot.(wide open throttle)
An outboard will use about 10% of the hp in fuel 5 gph(gallons per hour).
with a 50. If you can get it to go a little faster it will save a slight amount because you get from here to there quicker. Also if hole shot is better you save fuel getting on plane. Measurable probably not.If it will run faster on less throttle, cruising speed, you save fuel and a tiny bit of wear and tear on the motor.Again measuring the amount saved would be difficult.

 

[robeward]

Re: New Prop

Got the numbers. My prop is 12.25x15