slowing down a Yamaha 15 HP 2-stroke

[docksider]

We use two small aluminum boats at the lake. The larger has a (1998) 15 yami and the smaller one an old 9.5 evinrude. I was thinking of getting a new 9.9 4 stroke for the smaller boat when wife suggested getting new 15-20 4-stroke for the larger boat, which we use more often, and moving the 15 to the smaller boat.

The smaller boat can handle the 15 or a (or 4 stroke if we went with the original thought), but it will go faster than we think safe for my daughters and others who will use it.

Sooo, is there a simple way to limit the throttle range on the Yami 2-stroke 15 hp or otherwise slow it do something more like a 9.9? (It would also be great to be able to go back and forth easily).

Thanks,
dock

 

[rodbolt]

Re: slowing down a Yamaha 15 HP 2-stroke

best I recall the only difference between the 15 and 9.9 2 strokes was the reed box. the 15 used a 3 reed box and the 9.9 a 2 reed box.

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

Must be an expensive reed for the price difference in motors. lol

I have to confess I don't know what a reed box is or what's involved in replacing it. Any info would be helpful. And, I'm grateful for this lead on the reeds.

Thanks.
dock

 

[BruceAML]

Re: slowing down a Yamaha 15 HP 2-stroke

Is there something wrong with the Evinrude that makes it unreliable? What year and model is it? How much use does it get? Sometimes you are better off with what you have. New is not always better. Most of the older Evinrudes will run forever if given reasonable care. I have a 1987 and a 1982 Yamaha that are both very reliable. I also have a few older Evinrudes (1950s and 1960s) that are very reliable.

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

The old evinrude runs fine, but has broken center mount, which I'm hoping to replace (this part is not easy to find) and the prop needs to be replaces (grrrrr, not my doing). It also has an uncomfortable steering position for some in my family.

I haven't given up on the old 9.5, but I'm exploring all options. I have to say the yami felt better on this particular boat, but the speed/rpm are concerns with certain potential users. Either way, I'm also hoping to get the old 9.5 all fixed up. I love that old motor.

d

 

[deejaycee_2000]

Re: slowing down a Yamaha 15 HP 2-stroke

you can adjust the throttle stop screw so the throttle can't turn to it's full potential ....

 

[BruceAML]

Re: slowing down a Yamaha 15 HP 2-stroke

Glad to hear that you love the old Evinrude. The secret to finding old Evinrude parts is to know the part number of the part you need. On the BRP web site there is an electronic parts system that goes all the way back to 1968. If you tell me the model of your Evinrude I can look up the part for you. I also have some older parts listings.

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

you can adjust the throttle stop screw so the throttle can't turn to it's full potential ....

That sounds like a simpler fix. I'd looked at the mechanism and saw a couple of things that might do the trick, but not sure which to try, I didn't adjust anything.

If how to do this is easily described, I'd be grateful for the guidance.

thanks again.
d

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

If you tell me the model of your Evinrude I can look up the part for you. I also have some older parts listings.

Thanks, Bruce. I'll look it up and let you know.

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

Bruce,
The model # is 9122R
Serial No. J12918

Thanks for checking.

dock

 

[deejaycee_2000]

Re: slowing down a Yamaha 15 HP 2-stroke

take the cowling off, and open and close the throttle .... you will then see the throttle bodies move up and down, when you get to full throttle position there should be a screw that stops the throttle body from moving further, it sits right there you can't miss it, now that screw you can adjust inwards to make the WOT less ......

 

[BruceAML]

Re: slowing down a Yamaha 15 HP 2-stroke

Could the model # be 9022? My Evinrude model guide has a 9022 which is a 9.5hp made in 1970.

 

[BruceAML]

Re: slowing down a Yamaha 15 HP 2-stroke

I did find a 9122R. It is a 1971 model. I need to email you a parts diagram so you can identify the mount. I see a lower rear mount [309707], 2 each upper side rubber mount [380964], 2 each rubber mount [309698], lower front rubber mount [380965] and upper front mount [380963]. Since your motor is only 36 years old it should be just broken in.

 

[docksider]

Re: slowing down a Yamaha 15 HP 2-stroke

djc2k, thanks for the info about limiting the throttle. I'll take a look when i get back to the lake.

Bruce, I'll look forward to your email. Thanks.

d