NS9.9D Throttle questions

[Bronlonius]

So I just finished converting my NS9.9D from remote to tiller.... Have a few questions.

1. Is the throttle on the tiller handle supposed to spring back to idle when you let go of it? Mine doesn't seem to do this. The linkage moves freely, but doesn't spring all the way back unless you twist the throttle by hand. Is there supposed to be a return spring somewhere or is that just the way it works? Never owned a tiller before, my other boat was a console steer.

2. It's my understanding that the only difference between the 9.9 and the 15 is the throttle cam. From what I can see, the current setup is opening the throttle up as it can can possibly open, leading me to believe that this mod has already been done. Is there a way to tell for sure? I can take pictures if that would help.

Thanks in advance for any help.

 

[Sea Rider]

Re: NS9.9D Throttle questions

Points:

1-All throttle sliding points must be well greased in order for the tiller to spring back, not to a perfect slow idle position though, would say just fast idle. There's a central nut on middle throttle plate (where rods meet) turn it CCW untill you find the sweet loose spot. Keep in mind that when fully throttling the acceleration will respond accodingly faster, so be aware of this situation specially if kids will use that horse.

2-You need to change the trottle cam for the 15D model, which has a higher hill end, at wot must have a wide 180? butterfly to be correctly adjusted.

Happy Boating

 

[Bronlonius]

Re: NS9.9D Throttle questions

Thanks,

I looked closer at the tiller, and it looks like there is a mark on the handle where it returns to, which must be high idle. I guess that makes sense, if you want it to idle lower for trolling than you twist manually to reduce rpms.

Next time I'm in the garage I will take off the air box and see what the butterfly looks like at WOT.

 

[Sea Rider]

Re: NS9.9D Throttle questions

Usually returns around both matching marks, grip and throttle arm body, which is the starting position when cold. Check if you still have the first cam, if so, must be changed for the 15 HP model which is the second one.

Happy Boating

 

[Bronlonius]

Re: NS9.9D Throttle questions

Thanks for the pics, that's helpful. It looks like I still have the 9.9 cam.

So from the exploded view of the throttle linkage, I see that there is a link rod (398-63717-0) that can be adjusted to two different lengths for 9.9HP(75mm) and 15/18HP(78mm).

I would assume the rod in your 15-18hp picture also needs to be adjusted, anything else?

 

[TOHATSU GURU]

Re: NS9.9D Throttle questions

No, you do not adjust the rod length. You replace the cam.

 

[Sea Rider]

Re: NS9.9D Throttle questions

Personally have not done any 9.9 to 15 HP conversions as we currently work with 18 HP models. 9.9D timing is usually factory adjusted to 22? so pass it to 25? by moving throttle stopper A screw & nut CCW accordingly untill this position is achieved. You'll probably need to re adjust carb rod height if carb roller is not resting at top of high hill cam once at 25? to achieve butterfly at 180? once at wot, check pics.

Happy Boating

 

[Bronlonius]

Re: NS9.9D Throttle questions

Thanks Sea Rider, very helpful.

 

[Bronlonius]

Re: NS9.9D Throttle questions

Okay so I finally got around to doing this mod. I bought a 362-63718-0 throttle cam last fall. Just pulled it apart and to me, it looks identical to what I already had, which looks like what is labelled as the 9.9 cam in Sea Rider's picture. However, I'm wondering if those pictures(post #4) are labelled incorrectly? From what I can see, it looks like one I already had, and the one that I bought, both have a bigger "hill" and as such would open the throttle as far as possible. Are those pictures incorrectly labelled, or did I buy the wrong part?

 

[Sea Rider]

Re: NS9.9D Throttle questions

9.9 throttle cam code: 364-63718-0 (9.9 D2)

15 throttle cam code : 3M3-63718-0 (15D2/18E2)

Seems you have purchased same 9.9 cam, now you have 2

Paul, will confirm or give correct codes if they have changed.

Happy Boating

 

[pvanv]

Re: NS9.9D Throttle questions

3M3637180M is used to convert 9.9 D2 models up with serial numbers higher than 71412. It will not work on serial numbers below 71413.

362637180M is used to convert 9.9 D2 models down with serial numbers lower than 71413. It will not work on serial numbers above 71412.

 

[Bronlonius]

Re: NS9.9D Throttle questions

Thanks Paul. My serial number is lower, my model is an NS9.9D, so it seems the conversion had already been done before I bought the motor. So Sea Rider's pictures in post 4 only apply to the newer models.

So out of curiosity, what does an early 9.9 cam look like? Anyone have a picture? Might help clear up some confusion for someone who reads this thread in the future.

 

[gobigdog]

Re: NS9.9D Throttle questions

Hello guys, thank you for your posts about converting Nissan / Tohatsu 9.9hp two strokes to 15hp! I've never posted here but have been "lurking" for a while. And I'm about to go look at a 1997, Nissan 9.9 electric start motor that is advertised to have very low hours, etc.

Paul, I've read that some older Japanese outboards are hard to find parts for -- are parts still available for 1997, 2-stroke 9.9/15hp Nissan outboards?

Thanks again,

 

[Bronlonius]

Re: NS9.9D Throttle questions

As you can see from this thread, the Model # and serial number are key in identifying the correct parts, the year really doesn't mean anything. But my guess is that what you are looking at is a NS9.9D or D2, since I found out after calling Nissan marine that my motor is a 1996(the model is NS 9.9D). From what I've seen most of the parts you'd need are still available, it's stuff like housings, cowl, tiller handles, etc. that are harder to find and/or only available used. The guy I bought my motor from swore up and down that I'd never be able to find a tiller handle, but there was one on ebay the day I bought it from him, and I later found out from someone on this forum that many dealers still have some of the stuff that is listed as "obsolete" by boat parts suppliers who are not actual nissan/tohatsu dealers. So far, the only thing I could not find for my motor is decals, but I ended up just having someone make some up for me and they look great.

 

[gobigdog]

Re: NS9.9D Throttle questions

Hi Bronlonius, thanks for answering my post! For a while, I've been looking for a good used 2-stroke, 15hp outboard and am definitely going to check out the '97 Nissan 9.9 today. I have a 6hp, 4-stroke Mercury (Tohatsu) that runs really well but it's just waaaaaay too slow. Also, for me simple-to-work-on engines are good, and I've always enjoyed the slightly castor smell of high quality 2-smoke exhaust on the water...

 

[Bronlonius]

Re: NS9.9D Throttle questions

These engines are actually very quiet for a 2 stroke IMO. I was shopping for a 4 stroke 9.9, and got a great deal on this one because the guy thought it could not be converted to a tiller. Really the only money I've spent on this so far has been on a prop(hub was spun), parts to convert from remote to tiller, gas tanks/fittings and on paint/decals... All of which are not really the motor's fault.