AOP
In Remembrance 2023
Hi everyone,
I am putting out a blanket call for ideas about some trouble I am having with my C-90. Still, not again.
I am running exclusively 100LL fuel.
4 Millennium cylinders with less than 200 hours on them.
2 months ago on annual, compression was 70, 60, 70, 70.
Removed #2 and took it to a cylinder doctor. Still there. Top web of cylinder around the valves and piston face have at least 1/8 in of crust around everything. Barrel and piston sides are slightly dark stained from combustion but shiny and unblemished. Suspect the cause is buildup of crud around exhaust valve seat. Valve face is burned and needs replacement. Seat appears salvageable.
I have always added Alcor TCP to the fuel in the recommended ratio, but it doesn't seem to be doing the job. Does anybody have any ideas about a fix to keep lead from building up and damaging the internal parts? I know that unleaded non-alcohol fuel is one answer, but the nearest place that sells no corn fuel is a good piece away and still has other additives that I am concerned about. However, I am willing to try it if it would help. Can the TCP ratio be increased without causing more trouble? Would it do any good? I have put the question to Alcor with no answer as yet.
Thanks for your consideration,
Paul Smith
I am putting out a blanket call for ideas about some trouble I am having with my C-90. Still, not again.
I am running exclusively 100LL fuel.
4 Millennium cylinders with less than 200 hours on them.
2 months ago on annual, compression was 70, 60, 70, 70.
Removed #2 and took it to a cylinder doctor. Still there. Top web of cylinder around the valves and piston face have at least 1/8 in of crust around everything. Barrel and piston sides are slightly dark stained from combustion but shiny and unblemished. Suspect the cause is buildup of crud around exhaust valve seat. Valve face is burned and needs replacement. Seat appears salvageable.
I have always added Alcor TCP to the fuel in the recommended ratio, but it doesn't seem to be doing the job. Does anybody have any ideas about a fix to keep lead from building up and damaging the internal parts? I know that unleaded non-alcohol fuel is one answer, but the nearest place that sells no corn fuel is a good piece away and still has other additives that I am concerned about. However, I am willing to try it if it would help. Can the TCP ratio be increased without causing more trouble? Would it do any good? I have put the question to Alcor with no answer as yet.
Thanks for your consideration,
Paul Smith
