Cowl flaps pop back open

[nels]

Just got my new to me 78 J model home. One thing that was going on that baffles me a little is the cowl flaps would open on their own. Actually it was a little startling the first few times. Anyway, are these spring loaded and supposed to travel over center to maintain their position or something along those lines? Is there an adjustment I could make to keep them closed during cruise?

[LANCECASPER]

Congratulations on the Mooney!!

There's a lot on this subject if you search "cowl flaps"

[markejackson02]

2 hours ago, nels said:

Just got my new to me 78 J model home. One thing that was going on that baffles me a little is the cowl flaps would open on their own. Actually it was a little startling the first few times. Anyway, are these spring loaded and supposed to travel over center to maintain their position or something along those lines? Is there an adjustment I could make to keep them closed during cruise?

Mine did the same.  There is a spring in the system which probably needs to be replaced.

[nels]

5 hours ago, LANCECASPER said:

Congratulations on the Mooney!!

There's a lot on this subject if you search "cowl flaps"

Thanks,

[Guest]

The cowl flaps are meant to lock over centre in the closed position, also there is an assist spring from the torque tube to the firewall.  It is above the right cowl flap.

Clarence

[marky_24]

On my 78 J there is only 3 position closed, in trail and fully open.  Over center one direction is closed, just passed over center is in trail, about 1/3 open and then over center the other direction is fully open. 

When I picked mine up the mechanism was snagging the scat tube in fully closed position and it would pop back to intrail in the air and would not stay closed. 

[Jeev]

Congrats of the Mooney!! Before you buy parts or take it in peek into the cowl and see if the flaps are contacting anything like the scat tube or exhaust.  

[nels]

Just now, Jeev said:

Congrats of the Mooney!! Before you buy parts or take it in peek into the cowl and see if the flaps are contacting anything like the scat tube or exhaust.  

I took the top cowl off today. The spring is there and door doesn't appear to be hitting anything but I'll look again tomorrow while cycling the door.

[dooleypster]

Congrats on the new Mooney!  There is a possibility of the linkage catching on the breather tube and/or a clamp holding same.  This happened to me.....very cheap fix.

 

[Jeev]

48 minutes ago, dooleypster said:

Congrats on the new Mooney!  There is a possibility of the linkage catching on the breather tube and/or a clamp holding same.  This happened to me.....very cheap fix.

 

Agreed, take the bottom cowl off (two person job so you don't scratch) and look all around the linkages and anything they may touch for score marks.  over time and after maintenance I have had my linkages rub on the exhaust and scat tubes.  If you don't see any evidence of interaction then take her on in you may need new springs or some loose rivets / brackets replaced.

Good luck hopefully it is a simple fix

Edited July 27, 2016 by Jeev

[bradp]

On July 27, 2016 at 4:28 PM, Jeev said:

Agreed, take the bottom cowl off (two person job so you don't scratch)

It's a one person job and you don't want to scratch if you are willing to learn about gymnastics and yoga at the same time.  

[Jeev]

On July 30, 2016 at 10:06 PM, bradp said:

It's a one person job and you don't want to scratch if you are willing to learn about gymnastics and yoga at the same time.  

HA!! I've done it solo but you indeed need to be god at yoga...  Much easier with a helper especially to put it back on...

[M20F-1968]

This could be an easy fix.  I had a similar problem with J model cowl flaps.  There is a single spring that attaches on the right side, and can be accessed through the right open cowl. 

Find a similar spring (I found one locally, same size, diameter and wire gauge) tried it ant it worked.  $1.50 fix.  Bought another 6 springs for the shelf.

John Breda

[nels]

John, I looked up through the gear door of mine and I could see the end of the spring hooked to a tab at a link rod end. I was able to loosen the nut on the tab and rotate the tab which stretched the spring about 3/4 inch then re tighten the nut. I haven't had a chance to fly it yet but I have a feeling the problem will go away.