WOT rpm's

[johnmark]

I have an 1983 johnson 50 hp (J50BELCTA) what should the WOT rpm's be?
I'm running a 12.25 x 15 SS prop and only getting 4200 rpms @ WOT and 22 mph on speedo. Thanks you guys., John Mark

 

[steelespike]

Re: WOT rpm's

The hp is rated at 5,000 rpm most would set it up to operate at a max of about 5,500.Your obviously very low.Not good.
We need to figure out if the problem is motor related or prop/setup related.
We need to know your brand,boat size and weight.Is the performance info based on a light load driver only?Depending On your boat the 15 inch prop is in the ball park.

 

[johnmark]

Re: WOT rpm's

The seloc manual states set the the WOT timing at 19 degrees at 4500 rpms.

Its a old 15 ft, deep V, 1965 wizard. The boat's transom was made for a 15" motor,my 50hp is a 20".I put a manual jack plate on her and have the plate even with the keel.
I will get the boat weight,and I just got a 11.75 x 13 AL. prop. I also set the timing the Joe Reeves method. Will update soon as I can Thanks again.
John Mark