Pilot reported engine roughness during departure. The pilot decided to troubleshot and continue to the original destination. The issue got progressively worse; but the pilot was able to safely land at destination.
Synopsis
Pilot reported engine roughness during departure. The pilot decided to troubleshot and continue to the original destination. The issue got progressively worse; but the pilot was able to safely land at destination.
Narrative
Having flown to ZZZ for lunch; I left ZZZ with a destination of ZZZ1 (home base). Shortly after climbout I experienced rough running [engine]. The engine was still producing power; but it was obvious somethings was wrong. I was able to continue climbing as I tried to diagnose issue. I checked fuel pressure (OK); checked oil pressure & temperature (OK); isolated individual magnetos (same roughness on each); adjusted mixture settings (I could make it worse but not much better). I looked at EGTs & CHTs and noticed cylinder #4 was abnormally cooler than the other 5. I deduced I had a partial combustion issue with number 4. Since the Laser has a glide ratio similar to a brick; I decided best course of action was to stay as high as possible until over the airport. ZZZ1 sits below the upper tier of ZZZ2 class C; so I called ZZZ2 approach and requested a high orbit over ZZZ1. As I approached ZZZ1 the engine cleared noticeably. As I arrived over ZZZ1 I contacted ZZZ1 Tower. They gave me priority landing and I landed without incident. Tower at ZZZ1 was also very helpful. Upon taxi to hangar; a runup to max brake holding power was done with little to no roughness noticed.After the engine cooled; I pulled spark plugs & inspected with very little variation between cylinders (not unexpected as the problem cleared at end of flight).All 6 injectors were carefully pulled & inspected. All clean except a speck in #6!Fuel flow from fuel divider into 6 graduated cups showed no anomalous variations.All 6 injectors cleaned & reinstalled.Spark plugs reinstalled.CHT/EGT temp sender wiring was verified.Fuel sumped.Engine test run on ground with no issues.Engine data downloaded for review at home.Engine re-cowled.After review of engine data; CHT/EGT plots for #6 showed some minor anomalies; but not as bad as #4. Today (DATE) after another ground run; a test flight was performed. Engine ran smoothly and developed normal power. Assumption - Partially clogged #4 injector that then passed the debris and minor clog in #6 injector that was removed when cleaned. Both ZZZ2 approach & ZZZ1 tower were very professional and accommodating.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.