NicoN Posted April 12, 2019 Report Share Posted April 12, 2019 Our 1980 M20K cowl flap was always hard to control. It needed a good portion of muscle power to close them. Recently, we fine-tuned the baffles. As a result oil temperature decreased and also #2 CHT decreased a little. But, as a side-effect handling the cowl-flap is now even harder than before. Moving from open to the first position is more or less the same, but closing to the second position needs a lot of power. One of my co-owners tends to kick it to the close-position with his right foot! Definitevely not the right way! NOw, one of my colleagues is suggesting to install the electrical cowl flap (drive?). Is that possible? Is there a mod available? Or is simply a fine-tuning on the cowl flap possible to reduce the force needed? Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 12, 2019 Report Share Posted April 12, 2019 The history on motors for that application seems to have the same challenge... Might want to check into what is causing the difficulty. I suspect there is a wear or other maintenance item that may improve things significantly... a search on flap motor overhaul may reveal the situation... PP thoughts only, not a mechanic. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
NicoN Posted April 12, 2019 Author Report Share Posted April 12, 2019 On ground opening and closing the cowl flap seems for me as easy as ever. Thank you for your ideas. Quote Link to comment Share on other sites More sharing options...
ziggysanchez Posted April 12, 2019 Report Share Posted April 12, 2019 49 minutes ago, NicoN said: On ground opening and closing the cowl flap seems for me as easy as ever. Thank you for your ideas. It does seem strange that it is difficult to close them while in flight. Mine initially require a little effort when closing but once I get the lever moving forward the have a tendency to almost slam shut with the force of the wind. Trying to open them in flight definitely requires some effort. If they open and close easily on the ground it may be that they just need to be adjusted. You may also want to check the spring on the cowl flap. When I first bought my K mine were extremely hard to open and close both while on the ground and in the air (more so in the air). One day while opening them the cable broke and the handle pulled completely out of the housing. It looked as if someone over the years had been twisting the handle and it had developed a kink in the cable that was making it almost impossible to open and close. It finally just wore the cable out and it broke. With the new cable closing the cowl flaps on the ground is a one finger operation and opening them is just as easy. Quote Link to comment Share on other sites More sharing options...
bradp Posted April 12, 2019 Report Share Posted April 12, 2019 Sounds like you need some fools old fashioned maintenance instead of a 337. Cable routing and springs condition are first places to check. If you disconnect the door from the actuator does it move freely? Quote Link to comment Share on other sites More sharing options...
larryb Posted April 12, 2019 Report Share Posted April 12, 2019 Tri flow on the cowl flap linkage. I do this every oil change. Quote Link to comment Share on other sites More sharing options...
PT20J Posted April 13, 2019 Report Share Posted April 13, 2019 Get out the IPC and make a list of the parts you'll need to do the conversion. Call Corrine at LASAR and get a price quote. When you get off the floor, I think you'll decide to figure out how to adjust/lubricate/live with your present cowl flaps. 2 1 Quote Link to comment Share on other sites More sharing options...
N231BN Posted April 14, 2019 Report Share Posted April 14, 2019 You need to have your link rods lengthened. The 231 cowling has much too little exit area so if your cowl flaps are set to close flush you are creating a lot of pressure. Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted April 14, 2019 Report Share Posted April 14, 2019 On ground opening and closing the cowl flap seems for me as easy as ever. Thank you for your ideas. Make sure there isn’t any interference, in my case it was rubbing on the fuel line. Things can move a little during flight, so if a hose or wires are close, maybe they need to be better secured.Tom Quote Link to comment Share on other sites More sharing options...
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