need help with Yamaha 4hp 4-stroke

[MikeZ]

Howdy All,<br />I recently bought a "boat Package" that included a 14 foot G3 aluminum boat with a Yamaha four stroke 4hp on it. I was given the impression the boat would move a quicker then it does. Has anyone ever played with different props on this engine or found way to get a little more "umph" out of it. Not trying to make a ski boat out of it just looking to get a few more mph's .Any info much appreciated.<br />Mike

 

[JB]

Re: need help with Yamaha 4hp 4-stroke

Howdy, Mike.<br /><br />To go faster you will need a bigger engine. That F4 is intended for trolling speeds.<br /><br />Good luck.<br /><br />Red sky at night. . .<br />JB

 

[Forktail]

Re: need help with Yamaha 4hp 4-stroke

I have an F4 on a 14' Lund which I use strictly for small lake trolling, as J.B. said.<br /><br />I'm not aware of any prop options on this motor. Adjusting the weight in the boat bow/aft will make a small difference.

 

[MikeZ]

Re: need help with Yamaha 4hp 4-stroke

Thanks guys for the replys. I was just trying to get a couple more mph's out of it. Forktail, since you have one maybe you can answer this question. On mine there doesnt seem to be much if any difference betweeen 1/2 and full throttle. Is this normal for a kicker this size or should I see a difference?<br />Thanks<br />Mike

 

[Forktail]

Re: need help with Yamaha 4hp 4-stroke

You might see a difference on a smaller boat, say 12' or a square stern canoe, etc. But the 4hp is really underpowered for that boat. When this happens you want thrust. Increased rpm in an underpowered situation does little for thust. Save some fuel and back off.<br /><br />There does seem to be considerabbly more noise on the top half of the throttle, making it seem like you could really scoot, but it just doesn't happen. I think if you could get her on step (which will never happen with the 4hp), the top half of the throttle range would make more of a difference. Otherwise the hull drag on the boat overcomes any added rpm of the prop.

 

[jeff99705]

Re: need help with Yamaha 4hp 4-stroke

Hello from Alaska!<br />I recently bought a Yamaha F4 for my 17' Osage square stern canoe. Spring isn't here yet so I haven't run the motor, and I can't wait! Could you F4 owners tell me of your impressions of this motor? Is it quiet? Low fuel consumtion? I don't expect a lot of performance with the canoe, just want something very quiet and fuel efficient for moose hunting on remote rivers this fall. Thanks.

 

[my new fishmaster]

Re: need help with Yamaha 4hp 4-stroke

Thats to small for real speed. I had a 90 starcraft fiberglass 17 foot boat with 80merc and a new Honda 4stroke 8. It pushed that boat around the lake just fine. Sell the yammy and get something bigger.

 

[martinlogan]

Re: need help with Yamaha 4hp 4-stroke

I hope you didn't sell the yamaha 4HP.. I've got a 5hp Nissan 4-stroke on a OLD TOWN CANOE 15' and with myself in it(6'7 308lbs)it planes out just fine and move 16mph according to my Garmin GPS, with myself and my buddy in it it run about 11 mph.. operating at roughly 5500rpm.