1992 15 HP WOT Operating Range

[scout-j-m]

I have a new to me 1992 Johnson 9.9 hp with a 15 hp carburetor. It came with a 8" pitch 3 blade aluminum prop in good condition. I have only had it out on the water once on my 1648 Alumacraft flatbottom and it peaked pleasantly at 19 mph at 6800 rpms with two people and light gear. I was thinking the WOT range would be 5500-6500 rpms and I would definitely need to re-prop but I got the factory service manual in the mail yesterday and it states it is 5500-7000 rpms. Is the manual still correct or was there ever a TSB or anything that came out that recommended it be lower?

I still plan to try out a 10 pitch prop I already have as I would like a little more speed but I also don't want to over-prop it and be down in the lower portion of the WOT range.

 

[thumbnut]

Spiner up to 7000 with the lightest load the boat will see. If it sees 2 people most of the time set at 7000 or close. Just don't run it at wot when alone too long. jmho

 

[scout-j-m]

Thanks thumbnut.

BTW, if a mod sees this could you possibly move this thread to the propeller forum?...it may be more appropriate to have it there. You can be the judge.