Mandatory ALERT Service Bulletin: Inspection and Replacement of Oil Spray Nozzle for ROTAX® Engine Types 912 i, 915 i, and 916 i (Series) SB-912 i-016 / SB-915 i-016 SB-916 i-006

Jeff Blakeslee wrote:

Hi Harry

Regulator and flow meter at links below:

https://www.amazon.com/dp/B01BPQDG62?ref=ppx_yo2ov_dt_b_fed_asin_title&th

https://www.amazon.com/dp/B07DNW6JHX?ref=ppx_yo2ov_dt_b_fed_asin_title

Since the Rotax crankshaft plug o-rings are on national backorder, I ordered a pack of 10 of these (link below). I have not received them yet so I can’t vouch for proper fit but they are the exact same spec. Probably some folks are putting the original back in - not the best practice but it probably would be fine.  

https://www.amazon.com/dp/B005RUSMJ4?ref=ppx_yo2ov_dt_b_fed_asin_title

The flow meter I suggested has 8mm nipples and will fit (tight) with 1/4” ID rubber or vinyl tubing. The regulator has 1/4” NPT threaded  hubs so you can get what ever hose barb fittings you want as long as they have 1/4” NPT threads.

I adapted down from 8mm at the flow meter output so I could run vinyl 3/16 tubing to the insertion tool. I did this because I wanted this tubing very flexible so the tube did not put any pressure on the tool when inserted in the crankshaft. The other way to go would be to use really flexible 1/4 tubing like silicone which will push right on to the flow meter nipple.  Remember, you are only using 4 PSI, and you don’t want to be fighting stiff tubing when inserting the tool.

I bought the Omnav print file and printed my own insertion tool.  At the time I did not realize he was selling the actual printed tool for 1/2 the cost of the print file, but buying the pre-printed tool is a better way to go for a single use. If you go that way it comes with the O-ring and 1/4” hose barb.  If you are printing your own, you will need an O-ring.  I don’t know about other printed tools, but the O-ring I used is 1/4” OD, and 1/16” thick, I believe this is size A006 and most O-ring kits have this size. I used a Viton-75 O-ring, which has a durometer of 75. I have not tested it on the engine, but that was the recommended size for the tool I printed.

I also designed and printed the backplate and hook so the flow meter and regulator can be hung on the engine mount.  If you have a printer I can post that file.  I probably overkilled it, but have a few engines to test and I did not want to be fighting the thing. 

Do you have recommendation on the barbed adapter?  I am measuring the hole at about 5mm, which would think I would need the threded end as an M5, but I think I read it is an M6?   I assume the barbed end could be sized based on the tubing used between the flow meter and the tool.  What size did you find works best?

Thanks in advance,

Harry

Marc Houston wrote:

What is the best way to get ahold of Omnav in order to purchase the printed tool kit?

Marc,

I just checked the Omnav website and he has changed what he is advertising.  He now has the .step file to CNC the tool from aluminum. That file costs $100.00. He has dropped the price for the 3D printer file (.stl file) from $80.00 to $20.00, but no longer has the complete printed tool for sale. Here is the site, you could contact him and ask if he would print you one.

https://nd02u5-1f.myshopify.com/collections/all

Harry,

I don’t know what printed tool you have.  The Omnav tool has the port for the barb sized for 1/8” NPT.  If the hole in your tool is 5mm then it will probably thread out to 6mm.  I see both 5mm and 6mm thread hose barbs on Amazon that are for 6mm hose.  6mm is very close to 1/4”, so 1/4” ID hose will fit if that is what is available.  As I said in my earlier post, flexibility of that section of hose is important, so don’t go any bigger than 1/4”.  I used 3/16” tubing that I had left over from an aircraft oxygen system nasal cannula. You could also use 1/4” silicone tubing which is very flexible.