2 small but vexing squauks on a 201

[GoDores]

I'm flying an '84 M20J, and over the past couple years it's developed two problems that aren't of major concern but that I'd like to find answers for.  Our A&P hasn't been able to figure either problem out.

1) The ram air door no longer fully opens.  The knob starts to pull out, but quickly becomes very difficult to pull, to the point where I'm afraid of breaking something if I pull any harder.  I'd estimate the door rotates about halfway when the knob is pulled as far as I can pull it.  There are no obvious problems when looking at the door mechanism with the cowling off.

2) The mixture knob will slowly turn clockwise in flight.  Our A&P has tried tightening the knob from the outside of the panel with no effect.  It seems to rotate to a given point and then stop.  The vibration is in the direction that richens the mixture, never the other way.

These have been bugging us for a couple years, so I'm hoping there's a fix other than "replace everything".  Thanks!

[GeorgePerry]

Both of these sound like easy fixes...My suggestion to you would be, get a second opinion, or better yet go to your nearest Mooney service center and have the "experts" check it out.

Aside from that piece of obvious advice -

As so far as the ram air door cable is concerned, It sounds like the cable has a kink.  I'd recommend disconnecting it from the door and try to actuate the cable's full throw.  If you get similar binding issues, then you can try to find the kink and straighten.  If unsucsessful, then it's probably time for a new cable.  Unfortunately they are expensive.  I replaced mine for a similar issue last year.  Mooney factory part was $450.00 plus install.

As for the mixture, over to the forums for suggestions as our mixture control systems are different.

[GoDores]

Thanks for the thoughts on the cable.  Do you recall how many hours it took when you replaced your cable, or how difficult of a job it was?  We do as much work as possible ourselves, supervised/assisted by our A&P.

[KSMooniac]

On a 201 I would say it is cheaper and better to simply remove the ram air system entirely since it is ineffective.  There is SB guidance to do so, which happened on the later models from the factory.  That little orange seal is very expensive too, and prone to wear and abuse since it snubs the lower cowl.  I removed mine prior to paint last year and the paint shop filled the hole on the cowl and now you cannot tell.  If faced with replacing that seal or the cable, I would opt to remove the entire system and pay less money to get the cowl fiberglassed and repainted.

If you insist on keeping it, you could remove the cable and have McFarlane duplicate it for a reasonable cost.  Removing it is a PITA in my opinion, and I would not want to reinstall it. 

[GeorgePerry]

Quote: GoDores

Thanks for the thoughts on the cable.  Do you recall how many hours it took when you replaced your cable, or how difficult of a job it was?  We do as much work as possible ourselves, supervised/assisted by our A&P.

[Parker_Woodruff]

Quote: JimR

Regarding the mixture issue, in order to tighten the friction, try loosening the front nut first, then loosen the large nut behind the panel a bit, and then retighten the front nut.  At least, this was Don Maxwell's suggestion when this question was posed recently on one of the Mooney email lists.  He also mentioned that under the front nut is a packing that wears out and that you can add to it to extend the life of the cable. 

Jim 

[KSMooniac]

I think I spent about 2 hours removing my cable.  The bits on the business end are easy, but there is a microswitch assy attached to the cable housing behind the panel that has major access difficulty, and there is a nut that needs to thread off the housing while removing it, which of course has access difficulty.

On a 201 it just isn't worth having that system...it works great on the E/F though.

[GoDores]

Thanks!  We've tried tightening the front nut on the mixture cable but not after loosening the back, which sounds like it has the effect of pulling the cable out of the panel and thus increasing the tension on it.  I'll try that this week.

I'll also take a look at the ram air cable - hopefully we can remove and straighten it to fix the problem, but we need a replacement for $450 then I think it's worth doing.  I know some people remove them, but when it was working correctly we got 1/2" of MP out of it.  If I didn't want every last knot, I could be flying a 182 :-p

[FlyDave]

If you need to replace the gasket between the RAM air door and the lower cowling, LASAR has a replacement gasket for $35. The Mooney replacement is somwhere in the area of $160.

[MooneyMitch]

Quote: Parker_Woodruff

 I had a similar issue with my Prop Vernier turning clockwise and always increasing RPM....and I believe this was Don's fix at annual.  no probs since.

[KLRDMD]

Quote: KSMooniac

On a 201 it just isn't worth having that system...it works great on the E/F though.

[KSMooniac]

Quote: KLRDMD

The RAM air is disabled with the Ray-Jay turbo installation on the E/F 

[Kwixdraw]

Not sure if the situation is still the same but some years ago I had the mixture problem and couldn't get the packing through Mooney, just the complete cable. Go to a (choke, choke) Cessna dealer and they can get you the proper packing. I recall it as being a thick felt piece in my assembly.

Be sure to check over all the pivot bushings in the ram air. That stuff takes a beating from vibration and tends to get pretty sloppy. I think there were a few instances of broken bits going into the intake and that's one of the reasons Mooney tries to get you to eliminate the system.

[GoDores]

Thanks for the help!  We were able to get the mixture cable tightened, and that appeared to solve that problem - the knob stayed still over almost 10 hours of flying this weekend.  Unfortunately it looks like the ram air cable will have to be replaced.  Probably won't get to that for a little while, since we had to replace the starter this weekend

[Mcstealth]

Quote: GoDores

Thanks for the help!  We were able to get the mixture cable tightened, and that appeared to solve that problem - the knob stayed still over almost 10 hours of flying this weekend.  Unfortunately it looks like the ram air cable will have to be replaced.  Probably won't get to that for a little while, since we had to replace the starter this weekend

[GoDores]

The exact same one that was on there, a lightweight Sky-Tec 149NL.  Fortunately a pretty common model and the local shop had one, although it was $150 more than from Aircraft Spruce 

 

On edit: it failed on a Sunday night 600nm away from home - this wasn't a voluntary or preventive replacement.  I was stuck.

[Mcstealth]

Quote: GoDores

The exact same one that was on there, a lightweight Sky-Tec 149NL.  Fortunately a pretty common model and the local shop had one, although it was $150 more than from Aircraft Spruce 

 

On edit: it failed on a Sunday night 600nm away from home - this wasn't a voluntary or preventive replacement.  I was stuck.