What's new
Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

Rotax SI on Fuel Pumps 8-25-2025

D

docjjrmd

Well Known Member
Benefactor
I received notification of a new SI for Rotax 912is engines yesterday. In it it discusses 912is fuel pumps, installation and reason for pump change as it relates to fuel vapor lock. Seems we have been around this block a couple times before. Often these emails indicate some minor change in previous documentation and generally don't cause concern, i.e. fixing typos, changing dates, etc. This time around though, I noted that the pump part number referenced was not what I received with new engine in January of this year. So do I order new pumps per the SI, wait for a service letter from Vans, or stumble blindly forward. Anybody know for sure what the right pump number is supposed to be given the new "upgraded pumps" on the modified RV-12? I only ask as its a simple enough change pumps today before I put the tail cone on for good. I really don't want to fight replacing the pumps afterwards. Thoughts appreciated...


[td]
Hello Flying Friend,

We would like to inform you that there is new technical documentation for the 912 i Series available:

  • Document Type: SI
  • Title: Fuel pump for ROTAX® engine type 912 iSc/iS Sport (Series)
  • Release Date: 25. August 2025
  • Important: Please review the entire document carefully. In updated documents, new changes are marked with a revision bar. Initial issues do not contain revision markings. In manuals specifically, changes are also summarized in the chapter "TOA – Table of Amendments".
​
[/td]​
 

Attachments

The pumps are a different size.. so you won't be able to just drop them in with existing hardware. Your best bet is to just wait until Vans comes out with a Service Letter and has the parts to mount it. It'll likely be an entire rework of the assembly back there...
 
Last edited:
rcarsey said:
The pumps are a different size.. so you won't be able to just drop them in with existing hardware. Your best bet is to just wait until Vans comes out with a Service Letter and has the parts to mount it.
Click to expand...
It appears the 889731 pumps referred to in the SI are the larger pumps that are in the improved RV-12is mounted in the tail cone floor. Substantial plumbing difference. As best as I can tell, Rotax instituted this pump change and the larger pumps are the suggested standard pump now. That is what is implied in the service instruction notice. I presume (dangerous, I know) that Rotax is shipping the larger pump now with their new engines.

The 889691 pumps that were shipped with my engine will obviously still work and can be installed without modification, though, as you are painfully aware, fuel pumps have been an achilles heal for Rotax, subject to change without warning. The 731 pump is universal now for 912 through 916 engines. Requires different check valves I think as well and has higher flow rates which makes me wonder about the cross over orfice size. Major rework of fuel system, new line path, different electrical connections, higher amp draw, new bypass orfice size. This is a headache for Van's engineering.

Building ELSA I will put what the KAI's say to do. Just hope a Service Letter doesn't come out and deep six's all the work. What would be simple now would be a b.... after tailcone attachment.
 
I get that there's time-consuming design & testing work involved, but a notice from Van's along the lines of "we're working on it, and here's a very rough timeline" would certainly be welcome.
 
7 months later...

Fuel System Update Kit for RV-12iS Using New Rotax Pumps​

$670.00
Part Number
SL-00121-KIT​
 
Has anyone purchased the 00121 fuel system update kit? I would like to get the part numbers for the access hatch. Support doesn't know and either does Store. I could not identify the parts listed in the SL.
 
In case you still need this info, I believe that to install the new access panel you will need:
F-01282-3-L Template
F-12350 Doubler
F-12352 Cover
F-12353 Skin Cover
Service Letter 00121 Rev 2 has instructions
 
A Dremel with a cut off wheel for the straight sections and a pointed diamond bit in a Dremel for the curved sections. In each case I made multiple passes.
 
You must log in or register to reply here.
Back
Top