Flew an hour this morning, found a problem that I can't explain.
After takeoff while climbing through 1400 feet, the engine abruptly became slightly rough. Grounding either P-Mag makes the roughness go away. (Grounding both P-Mags makes the engine very (too) quiet). The engine runs smooth on either P-Mag, but the roughness returns instantly when the second P-Mag is ungrounded again. This seems rather contralogical.
Engine is an ECI IO-360, 31 hours since new. OAT is 32F. The roughness is slight, not enough to make one immediately look for NRST, but clearly not as smooth as it was yesterday, discinctly noticeable. Fuel is 100LL. Injection is from Airflow Performance. The roughness is distinctly connected to the action of the p-lead switch.
Each P-Mag has a cooling blast tube. The manifold ports are tee'd together. Manifold pressure gage readings respond normally.
P-Mags are hardwired for the lower advance curve (A-curve??).
The roughness is less noticeable when leaned, but still distinct. The roughness is noticeable at all flight engine speeds. Below the constant prop control speed, grounding either P-Mag causes a 10-20 rpm drop, either P-Mag. Swithching off ships power to the P-Mags didn't appear to make any difference.
EGTs start rising when running on just a single P-Mag, and drop when returned to both.
Flew for an hour, the entire time the engine was exhibiting these symptoms.
Will put in new plugs and see if that makes any difference.
I am not making this up. I do not want a disease named after me. I want my smooth engine back! Any insight would be appreciated.
Thanks!
- Roger
After takeoff while climbing through 1400 feet, the engine abruptly became slightly rough. Grounding either P-Mag makes the roughness go away. (Grounding both P-Mags makes the engine very (too) quiet). The engine runs smooth on either P-Mag, but the roughness returns instantly when the second P-Mag is ungrounded again. This seems rather contralogical.
Engine is an ECI IO-360, 31 hours since new. OAT is 32F. The roughness is slight, not enough to make one immediately look for NRST, but clearly not as smooth as it was yesterday, discinctly noticeable. Fuel is 100LL. Injection is from Airflow Performance. The roughness is distinctly connected to the action of the p-lead switch.
Each P-Mag has a cooling blast tube. The manifold ports are tee'd together. Manifold pressure gage readings respond normally.
P-Mags are hardwired for the lower advance curve (A-curve??).
The roughness is less noticeable when leaned, but still distinct. The roughness is noticeable at all flight engine speeds. Below the constant prop control speed, grounding either P-Mag causes a 10-20 rpm drop, either P-Mag. Swithching off ships power to the P-Mags didn't appear to make any difference.
EGTs start rising when running on just a single P-Mag, and drop when returned to both.
Flew for an hour, the entire time the engine was exhibiting these symptoms.
Will put in new plugs and see if that makes any difference.
I am not making this up. I do not want a disease named after me. I want my smooth engine back! Any insight would be appreciated.
Thanks!
- Roger