Slight lean condition on right cylinder

[dag8501]

As the title states, I am running into a slightly lean condition on the right cylinder according to the spark plug. My alcohol-fueled cub motor is calling for the right-cylinder power jet to be completely closed while the left-cylinder power jet is only one turn from completely open. With these power jet setting the spark plugs read identical. These are the things I have check when troubleshooting: Cleaned the carbs and swapped sides, swapped sides with the spark plug boots, leak-checked the motor (held 7 in. of vacuum overnight), and changed the spark plugs multiple times. What am I missing? Could bad reeds cause this problem?

[dag8501]

Bump. No thought from the experienced troubleshooters?

[dag8501]

2026 bump. Still can't figure this one out.

[locogato11283]

What carbs?  

 

[dag8501]

TM 38 bored to 41mm. I swapped the carbs from one side to the other and the condition was unchanged.

[locogato11283]

Your information is off. You say that right cylinder is lean but you have to close the PJ completely, while the left is open.

Can you clarify this? Sounds like the left is lean and the right is not.

[dag8501]

You are correct, sorry for the confusion. The left cylinder is leaner. Left carb power jet is 1 turn from completely open while the right carb power jet is closed. With this setting, the plugs look similar. 

[locogato11283]

21 minutes ago, dag8501 said:

You are correct, sorry for the confusion. The left cylinder is leaner. Left carb power jet is 1 turn from completely open while the right carb power jet is closed. With this setting, the plugs look similar. 

I have heard that the transmission oil in the right side can help keep that side cooler. If you have verified there are no air leaks, compression, squish, etc is the same, just run it.

[dag8501]

Thanks. I have verified all those things. 195 psi on each cylinder, .040 squish on each side and the motor easily passes leakdown. Just wanted to make sure I wasn't missing something.