Page 1 of 2

Rotax ring mount

PostPosted: Wed Mar 27, 2024 5:28 pm
by sonex892.
I'm currently building a what will be a rotax powered sonerai and have decided to avoid the bed mount. I'm attempting making my own ring mount.

One problem I have encountered is the bottom left water pump bent socket will interfere with a mount tube and needs to be turned. I see in the manual this is supposed to be threaded and needs to be heated as its held in with loctite.

Any one have any tips on what to do, and what not to do when removing this tube?

Here is the mount so far
Image

Re: Rotax ring mount

PostPosted: Wed Mar 27, 2024 5:44 pm
by Skippydiesel
Nice work!

Re: Rotax ring mount

PostPosted: Wed Mar 27, 2024 6:20 pm
by 13brv3
Zenith has a manual online with some info. That's pretty much what I went by.
http://www.zenithair.com/stolch701/data ... ring-2.pdf

I'm sure there have been different elbows over the years, but I definitely had to turn mine, and there's exactly no room to spare once you get a hose on there. It did require a lot of heat to get them loose, then I removed them, cleaned up the threads, and was able to do some trial fitting with no sealant to note the exact direction they have to point. Then you have to install them for real, with the special sealant, and hope you get fairly lucky on how the position ends up when it's tight enough. For as many engines as they sell for eventual ring mount use, you'd think they'd just position them all to work that way.

Re: Rotax ring mount

PostPosted: Wed Mar 27, 2024 8:19 pm
by sonex892.
13brv3 wrote:Zenith has a manual online with some info. That's pretty much what I went by.
http://www.zenithair.com/stolch701/data ... ring-2.pdf

I'm sure there have been different elbows over the years, but I definitely had to turn mine, and there's exactly no room to spare once you get a hose on there. It did require a lot of heat to get them loose, then I removed them, cleaned up the threads, and was able to do some trial fitting with no sealant to note the exact direction they have to point. Then you have to install them for real, with the special sealant, and hope you get fairly lucky on how the position ends up when it's tight enough. For as many engines as they sell for eventual ring mount use, you'd think they'd just position them all to work that way.


Thanks Randy. Good info there on the zenith link. I had just been battling with the tube in situ with no luck so far. I think the best plan will be to follow the Zenith method and remove the water pump.

The only other info I have found relating to fitting the ring mount to the engine was a Sling aircraft video https://youtu.be/8VdVPRlQunw

Re: Rotax ring mount

PostPosted: Wed Mar 27, 2024 11:27 pm
by WaiexN143NM
Hi guys,

Dont know if this part will help your situation. Look up www.skytekaircraft.ca
go to store look up zenith 750 and cruzer parts. Scroll down, see the rotax extension for tight situations.
Red anodized, $280.00
from canada, good store ive ordered many times.

best,

michael.

Re: Rotax ring mount

PostPosted: Thu Mar 28, 2024 12:08 am
by 13brv3
WaiexN143NM wrote:Hi guys,

Dont know if this part will help your situation. Look up http://www.skytekaircraft.ca
go to store look up zenith 750 and cruzer parts. Scroll down, see the rotax extension for tight situations.
Red anodized, $280.00
from canada, good store ive ordered many times.


The only thing I found looks like it just moves the water inlet fitting back. The offending outlet elbows are on the pump housing, so it wouldn't have any effect on those. Good thought though.

Re: Rotax ring mount

PostPosted: Thu Mar 28, 2024 4:11 am
by peterp
Hey Steve,

Rotax sell an 80 degree bend specifically for the ring mount. If you remove the waterpump housing to do it(much easier because you need heat to remove the wrong one) make sure to get the gasket. I've done a couple and yet to save the gasket.

Re: Rotax ring mount

PostPosted: Fri Mar 29, 2024 3:35 am
by sonex892.
Thanks for the suggestions. I am pretty sure I will need at least two 80 deg fittings and pump housing gasket.

I have just completed the ring mount, but havent test fit it it yet. SInce I had no 9/16 tube I used 5/8" with an additional 1/2" tube inside the 3 tubes that penetrate through to the other side of the ring. So due to using larger tubes I have surely caused additional clearance issues for the wires and coolant pipes.

Here is the finished rotax ring. Or if it doesn't fit, future shed art.
Image

Re: Rotax ring mount

PostPosted: Fri Apr 05, 2024 3:50 am
by sonex892.
Well this didn't go as planned. I assumed the width of the supports at the top of the engine would have been the same as the lower. Nah!. NEVER EVER ASSUME the top support is actually 10mm wider at 150mm than the easy to access lower support. I walked away from it for a week to decide what to do. Luckily I managed to get away with replacing just 3 of the upper tubes and 2 upper mount sockets.

The ring is now rebuilt and fits nicely. The only things to deal with were rotating 2 of the bent coolant pipe sockets. A third one will need to be replaced with an 80 deg fitting. I managed to remove the tubes with a heat gun. I did destroy the water pump gasket removing the housing, but I was ready for that after Peterp's warning. The ignition module rear bracket needed to be replaced to raise the module 5mm at the rear so the coil doesn't touch the mount.

Image

Image

Image

Re: Rotax ring mount

PostPosted: Fri Apr 05, 2024 10:31 am
by 13brv3
You're clearly a glutton for punishment :-) Looks good in the end, so persistence pays off!