rotax EGT Puzzle - Rotax 912 - 2006 CTSW

[robjahnke]

Thanks Roger. So is a 250 F split between the front and rear cylinders at 4600 RPM a problem?   There is less than 50 F difference between all cylinders at WOT. I think it depends on what is causing the split at lower RPM that matters. That is what I was trying to get people to explore with the PUZZLE question 🙂 If we were to understand what causes that phenomenon in the Rotax 912, we could better judge if there is anything we could/should do about it. If it IS a problem, it is easily 'Solved' by running at 5000 RPM. 

Rob

[Jim Meade]

By-the-way, for those in the upper midwest, My go-to guy on Rotax questions is Brett Lawton of Leading Edge Air Foils in Lyons, WI, southwest of Milwaukee.  tech@leadingedgeairfoils.com or  800-532-3462 ext 154.  Very competent, knowledgeable, good with troubleshooting and a pleasant fellow to work with.  Leading Edge, is one of the big Rotax distributors, along with CPS, Lockwood, etc.  I've always been happy with their support and work with Rotax.

 

 

[Roger Lee]

250F is way to far out. There are several things that could cause it. Normal is anywhere from 15F - 80F. Rotax considers anything at the 15F mark the same temp. When temps are up in the 1250F - 1500F 15F is nothing. Give me a call.

Brett's my go to guy for odd and weird problems.

[Tom Baker]

250° is the difference between front and rear cylinders. He is within about 50 side to side. I have not seen a 912 ULS powered CT with 4 position EGT probes, so I have no idea what normal is. I suspect what he is seeing is normal for the CT, and has to do both with the engine and installation designs.

[Roger Lee]

We had a nice talk on the phone and a far better understanding of what was happening and all the other details. I misunderstood the first post. What he has is normal.