Hello everyone,
I’m an ultralight enthusiast flying a trike in Japan. I’m currently dealing with an issue with my Rotax 582 engine (about 100 hours since new).
Recently, I’ve noticed a significant EGT temperature difference between the PTO side and the Mag side. Here are the details:
---Observations
Ambient Temperature: @10°C (50°F)
Cruising RPM: @5500
Before adjustment:
Mag side: 420°C (788°F) (needle position: 2nd from top)
PTO side: 510°C (950°F) (needle position: 3rd from top)
Temperature difference: 90°C (162°F)
Actions Taken
To reduce the EGT difference, I adjusted the Mag side to a leaner setting:
After adjustment:
Mag side: 510°C (950°F) (needle position: 1st from top)
PTO side: 535°C (995°F) (needle position: 3rd from top)
Temperature difference at cruising RPM reduced to 25°C (45°F)
Partial Throttle Issue
However, at around 4000 RPM (partial throttle), the EGT difference remains significant:
Partial RPM: 4000
Mag side: 360°C (680°F) (needle position: 1st from top)
PTO side: 510°C (950°F) (needle position: 3rd from top)
Temperature difference: 150°C (270°F).
Questions
Q1: At cruising RPM, I’ve reduced the EGT difference to 25°C (45°F), but the 150°C (270°F) difference at partial throttle concerns me. Is this normal for Bing carburetors, or does it indicate a problem?
Q2: The two needles are set two positions apart. Should I be concerned about this, or is it acceptable?
Q3: If this is indicative of a problem, where should I investigate, and how can I resolve it?
Additional Information
Carburetor synchronization is confirmed.
Propeller setup allows WOT at 6600 RPM.
Idle RPM is set to 2000 RPM on the ground.
The carburetors are otherwise in their stock configuration (main jets, etc.).
Both spark plugs show good coloration, indicating proper combustion.
I would greatly appreciate your insights and advice!
Thank you in advance!
