Choke cable stop nuts

[Tomfox]

I cannot see how to mount the stop nuts for the choke cable on the 912ULS at the two carburator levers. Does anyone have a picture?

Thanks
Tom Livermore
SS7 912ULS

[Dave S]

Tom,

Here is the closest shot I have from the right side of the engine. The tail is cut a little short, I would rather have left a little more cable sticking out past the nut.

[Tomfox]

Thanks Dave. It looks like mine. I have to loosen the whole lever to get the stop inserted into the hole in the lever

Thanks
Tom

[colospace]

So Dave/Tom, you DO have to loosen/remove the choke arm to get that stop nut in??
I have not found an orientation of anything today that would allow me to slip it in the back side, but the manual says nothing about have to remove the lever and reinstall.

[Tomfox]

I found it necessary to loosen the lever - but sometimes the gurus here find ways to do things easier than I do.
When I close out I will put a dab of the same locking epoxy I put on all of my electrical connections. Get you the spec tomorrow
Tom

[colospace]

Thanks Tom. I scanned thru the Rotax maintenance manual and did not find any mention of torque for this nut. Looks to be an M8 which Rotax would default to 24 Nm (17.7 ft-lb) torque per page 35 of their maintenance manual, but that seems a bit high for that nut. Do you (or anyone else) know where Rotax addresses the installation of this nut (i.e. the carburetor linkages)?

[Dave S]

Gary,

I would agree that the "standard" torque for an M8 does not apply to this application. A thin nut like that could easily strip. I don't remember ever seeing a spec for this nut. :confused:

Lacking anything else, I would make index marks with a marking pen, see what it feels like loostening the nut and then re-tighten to the same marks or a tich past the marks, apply some torque seal to be able to monitor it and go that way. In a pinch, find some nail polish - it's basically lacquer and makes a pretty good indicator like torque seal.

Happy 4th

[Tomfox]

I agree with Gary. I just retightened mine - not as precise as Gary suggested ( I like his idea). The torque values you have are based on the material, treatment of the material, number of threads, etc which I do not have.

I use 3M 2216 epoxy to tack my screws. It also serves as a quick inspection point to see if the screw has moved (get the colored kind). Mix a little flox with it and put a dab on the side of the screw head down to the base using a toothpick. I did this with all of my electrical connections. It does not set so hard that the screw can't be removed. Don't let it get down into the threads.

Tom

[jrevens]

That shaft has only about half the thread surface engagement of a "standard" bolt due to the flats machined on it. It appears to be made of brass to boot. It definitely shouldn't be tightened to "standard" torque values. Mine have spring washers under the nuts, so I would recommend just tightening until the washer flattens out & then snug it just a little bit more. That's just my opinion.

[colospace]

Thanks guys. I have not removed/loosened the nuts yet as my son is in town for the holiday (and my front steps on my porch broke last night, so there is today's project). Assuming mine has a wave/spring washer, I like John's approach of using that as an indicator. I think I will also put some torque seal on it too. I'm just surprised that, with all the warnings, cautions and prohibitions in the Rotax manuals, they don't address stuff like this.

[rv9ralph]

You have got me to thinking... so I looked up what I think you are looking for.

I went to the California Power System web site. Looked under Rotax Parts and followed the thread to the carburetors, found the nut for the choke shaft, item 37, then in the parts list is this listing for torque. "HEX.NUT M8X1 / TORQUE: 6-7 NM / 55-62 IN.LB."

I hope this helps.

Ralph

[colospace]

Super Ralph, I never would have thought to look on CPS's site for something like that. Good to know.

[rv9ralph]

I have found that torque values and Loctite/sealer notations are located in the parts listing of the exploded views of the Rotax 9 series. These views are usually found on the vender websites, CPS, LEAF and Lockwood. I don't know why these views/information are not included in the operators/maintenance manuals. I guess you will have to print the parts manual to get this information... or look online.

Ralph