This ongoing problem has plagued me for over 2 years, and 200 hrs of flight time. Near the end, the spark plugs were lasting less then 10 hrs and oil changes were done at 20 hrs, which was as black as coal by then. I rebuilt the carbs twice myself and had Lockwood do them 3 times. I drained and flushed the fuel system twice, and Lockwood did it twice.
Each time the carbs were done, and the plugs were changed, I would have a few hours of a perfectly running engine. We knew that it was fuel, but could not end the nightmare. I came close to replacing both carbs, but in retrospect, that would only have resulted in a smooth running engine "for a little while".
This Spring I flew the airplane down to Lockwood Aviation in hopes of a fresh eyes solution. The first thing Joe, the shop manager did was to ask Phil Lockwood to test fly my airplane. After a thorough preflight, which included a fuel sumping that entailed taking several samples, and pouring them into a clear, funnel shaped collector for a detailed look for debris, Phil would not fly the airplane. Following that, Joe had his staff clean the fuel system. Again Phil did his preflight and flew my RV-12. He was quite complimentary about the airplane.
Before flying back home, I decided to have Lockwood comply with the 5 year Rotax rubber change, after which Joe asked Phil to fly my airplane. Again, Phil did a thorough preflight, and again he rejected the fuel samples. He walked back into the shop and told Joe to pull the fuel tank. Admittedly, no one was excited about it but, Phil is the boss, so they complied. Upon draining and flushing the tank, very tiny particles continued to be flushed from the tank, which were being collected into a white 5 gallon bucket. It was determined that is must be Proseal deteriorating, which was finer than confection sugar and had a light sand color. Being 1,000 miles from my home shop, a new tank was ordered from Vans and installed. Problem solved.
In summary:
Only fresh 93 octane ethanol free auto fuel has been used in the airplane, which now has 550 hrs on it.
Each time service was done such as carb clean and/or spark plugs changed it would run great, "for a little while"
Sumping using the normal sump tool revealed no debris.
During one of the carb rebuilds at Lockwood, Joe had his staff run my carbs on his test engine which caused them to rebuild them twice before he was satisfied with the test run. The only problem was that after I installed them, it only ran great "for a little while".
This was an expensive and frustrating problem and I now have about 100hrs on it since the fix that Phil Lockwood identified. To this day I have no idea why my Proseal continued to deteriorate, but I am done with that tank.
There is much more to the story, such as, I have posted many many times on this site and the Rotax site, looking for a solution, but this is the short version. Also, I greatly appreciate everyone's help in trying to solve this problem This forum is fantastic!!
All in all, I love my RV-12..............Tom
Each time the carbs were done, and the plugs were changed, I would have a few hours of a perfectly running engine. We knew that it was fuel, but could not end the nightmare. I came close to replacing both carbs, but in retrospect, that would only have resulted in a smooth running engine "for a little while".
This Spring I flew the airplane down to Lockwood Aviation in hopes of a fresh eyes solution. The first thing Joe, the shop manager did was to ask Phil Lockwood to test fly my airplane. After a thorough preflight, which included a fuel sumping that entailed taking several samples, and pouring them into a clear, funnel shaped collector for a detailed look for debris, Phil would not fly the airplane. Following that, Joe had his staff clean the fuel system. Again Phil did his preflight and flew my RV-12. He was quite complimentary about the airplane.
Before flying back home, I decided to have Lockwood comply with the 5 year Rotax rubber change, after which Joe asked Phil to fly my airplane. Again, Phil did a thorough preflight, and again he rejected the fuel samples. He walked back into the shop and told Joe to pull the fuel tank. Admittedly, no one was excited about it but, Phil is the boss, so they complied. Upon draining and flushing the tank, very tiny particles continued to be flushed from the tank, which were being collected into a white 5 gallon bucket. It was determined that is must be Proseal deteriorating, which was finer than confection sugar and had a light sand color. Being 1,000 miles from my home shop, a new tank was ordered from Vans and installed. Problem solved.
In summary:
Only fresh 93 octane ethanol free auto fuel has been used in the airplane, which now has 550 hrs on it.
Each time service was done such as carb clean and/or spark plugs changed it would run great, "for a little while"
Sumping using the normal sump tool revealed no debris.
During one of the carb rebuilds at Lockwood, Joe had his staff run my carbs on his test engine which caused them to rebuild them twice before he was satisfied with the test run. The only problem was that after I installed them, it only ran great "for a little while".
This was an expensive and frustrating problem and I now have about 100hrs on it since the fix that Phil Lockwood identified. To this day I have no idea why my Proseal continued to deteriorate, but I am done with that tank.
There is much more to the story, such as, I have posted many many times on this site and the Rotax site, looking for a solution, but this is the short version. Also, I greatly appreciate everyone's help in trying to solve this problem This forum is fantastic!!
All in all, I love my RV-12..............Tom