propping a 200hp Johnson

[Cricket Too]

Hey guys, I was just reading Boilermaker's post about "Lugging" an engine. It was very informative and cleared alot up for me so, thanks. My question now is what should my 1999 twin 200hp Johnsons run at WOT? I have them on a 1993 Hydra Sport 25ft. walkaround. The boat with motors and gas weighs a little under 6000lbs.. At WOT i am getting about 5000-5100 rpms, this always seemed a little too low, I was thinking at least 5400. When I bought the boat the guy had 2 sets of props for it, he said one set was better out of the hole and one better for top speed. I'm not sure which ones are currently on there, but I will take a look at both pitches and get back, but in the mean time I really just need to know what the proper WOT RPM is beacuse I don't care about speed, but it would kill me to be straining these motors and lugging them up. Thanks alot. Mike.

 

[Hooty]

Re: propping a 200hp Johnson

5800 rpm won't hurt a thing. It'll hum at 6000.<br /><br />c/6<br />Hooty

 

[CKJR]

Re: propping a 200hp Johnson

mmcpack, i would definately run higher rpms. with the boat light fuel and persons you would want to tend toward the upper end of the rpm range. i am not sure of the rated rpm range but an upper limit of 5800 sounds reasonable. when the boat is loaded the rpms will definately drop. by the way , i have the same boat with a pair of 175's. i am using the 4 blade renegrade props and these blades run great. check the pitch of the props and post back. they are most probably 19".

 

[Dhadley]

Re: propping a 200hp Johnson

Your target rpm is 5800-6000 with an average load. Even when its light you'll never get past the limiters which are at either 6200 or 6700 rpm.<br /><br />Good luck!

 

[asgrinne]

Re: propping a 200hp Johnson

Have a single 200 ocean pro on a 205 Sundowner Cuddy. <br />A 14x18 Raker that had awesome hole shot top end of 51ish. Rpms in the 5400 RPM. <br />14x19 SS 53ish 5100ish<br />14x20 SS 54ish 5100ish Hole shot marginal. <br />I kind of thought that our RPM's were a little on the low side but very livable. <br />50ish on a Sundowner is all the hull should do. <br />Starts doing the Chine walk. Which i personally do not enjoy. <br />I was lucky enough to get a prop shop to loan me a 21 which i ran in deeper water and promply returned.

 

[Mettaree]

Re: propping a 200hp Johnson

anita: Check out Smart Tabs for that chine walk. They really, really work.<br />Jim