I'm thinking about getting a backup/kicker motor for my new boat (Snowwolfe's old boat)...a Wooldridge, 23' Alaskan II.
Main is a 200HP Merc Optimax and primary use is in the Fort Yukon/Porcupine area. Most of our runs are upriver on the Porc, so if we have a mechanical issue with the main, all the kicker has to do is help us move back downriver...but still I want to have something that will push upriver if needed (even if slowly).
Will a 9.9 hp motor do this, or should I be considering something a little bigger?
I have an 1993 Yamaha 9.9 on my Wooldridge. I think it's called a high thrust model but I'm not sure what that means. It won't really push me upstream on the Big Su, just barely hold in the current and maybe, at wide open, I could gain a little. It would probably help if I had a good straight prop because the one on it now vibrates quite a bit at high throttle. I've really only used it for trolling out of Valdez and at the Deshka River
People often think only of the HP rating, when in fact they should give some thought to the prop... . Often, problems can be cured if a person goes to a smaller pitch prop... Often a prop that has too big a pitch will just cavitate when the throttle is opened up.. I had an 18' hewescraft with twin 40 Props for running the Su/Yentna/etc... I had 10" Diameter and 14" pitch props for "speed" but if I lost a motor, I had to back off to a 10" diameter with a 10" pitch on the one good motor to get that boat home on one... Later I sold the Hewescraft and went to an 18' SeaArk shifting the same outboards over to the SeaArk... due to the truly flat bottom on the SeaArk, if I lost one 40HP with the "speed" prop, I could still keep up on step with just one 40 hp with the 10x14 prop... /John
Originally Posted by MRFISH
Going downstream I would think any of the high thrust 9.9's would do a good job. Would estimate going down the Yukon with the 9.9 you should be able to run 8-10 mph.
Upstream? Doubt a 9.9 would work, most likely would take a 15-25 to move a heavy boat beyond a crawl.
My choice would be either a Yamaha 9.9 HT or Mercury Big Foot 9.9. I believe you can plumb the gas line for the kicker into the main fuel line pretty easy. And the kicker mount could be welded onto the swimstep.