I recently re-built the Bing 54 carbs on my Rotax 503 (points ignition, not DCDI) and swapped out the jet needle and needle jets back to the factory recommendation. (I bought the engine used and apparently these parts had been swapped out at and some point earlier in its life) It had 2.74 needle jets and a 8H1 (I think) jet needles. I replaced them at my mechanics recommendation with 2.70 needle jets and 11K2 jet needles.
Before the swap, the engine was rather hard to start, would bog down on initial throttle application and the EGTs stayed in the 1100 to 1150 range with the clip in the #1 position. (all the way to the top which means the leanest setting) Throughout the mid to high throttle range, EGTs stayed fairly consistent.
After the swap, the engine (so far) has been starting on the first pull, revs very nicely from idle all the way up to full, but the EGTs seem to be a bit peaky. The clip is in the #3 position which is what I'm told is the "winter" setting. (It's -10C during the day this time of year) At low to mid throttle, EGTs are in the low 1000s, then, at just over 4000, they climb to just over 1200 and then at full throttle, they drop back down to 1100 or so.
Is this normal? I know that 1250 is the redline for EGTs and 1225 or so makes me bit nervous.
Before the swap, the engine was rather hard to start, would bog down on initial throttle application and the EGTs stayed in the 1100 to 1150 range with the clip in the #1 position. (all the way to the top which means the leanest setting) Throughout the mid to high throttle range, EGTs stayed fairly consistent.
After the swap, the engine (so far) has been starting on the first pull, revs very nicely from idle all the way up to full, but the EGTs seem to be a bit peaky. The clip is in the #3 position which is what I'm told is the "winter" setting. (It's -10C during the day this time of year) At low to mid throttle, EGTs are in the low 1000s, then, at just over 4000, they climb to just over 1200 and then at full throttle, they drop back down to 1100 or so.
Is this normal? I know that 1250 is the redline for EGTs and 1225 or so makes me bit nervous.
