C150: A Couple Questions

Chilito

Chilito

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Chilito
First post, here goes:

I am the proud new owner of a '68 C150. Mid-time engine, great compressions, and flies like a dream, though I do have a couple questions, as someone who has most of his time in a 172.

1. Oil drips. I have read the O-200 is notorious for them. It drips after shutdown, and periodically. It hasn't been burning any more oil than usual. Sometimes more drips, sometimes less. I wipe it up. Normal?

2. Shimmy. Sometimes, when the yoke isn't held full back during roll out, I get a pretty good shimmy, enough to vibrate the dash and shake the panel plastic and instruments. Not all the time, but every couple landings. Dampener? Loose scissor? Maybe it's my landing? :)

3. Rattling noise on climb out - only noticed when tanks are full. Comes from the pilot's side, sounds like a seatbelt out the door, but it's not that. Everything seems to be secure, and it stops after about 15 mins of flight. Door seals? Antenna? Screw loose?

Thank you in advance.
 
Shimmy - manually feel your torque links and see if they are loose. My mechanic installed a bushing kit cheaply. That plus new steering rod ends (worn out and loose) and shimmy dampener overhaul has cut down ours to a wince in a while occurrence.

Oil- it drips. Yep. Mine is very close to yours 1966, 700 hours on engine, we change the oil, add back in 5.5 quarts (don’t feel like waiting for the jugs to drain fully) and rarely have to add the remaining 0.5 quarts in 25 hours to keep it above 5qt. Yes there are a few drips on the floor.
 
Oil drips, where is it coming from, find the source and then report back. Is it just from the oil breather line, they will drip a few drops after shutdown.
Little Continentals love to make carb ice.
Rattle, look for loose wing root panels or inspection panels, or maybe interior pieces that might be loose.

I learned in a '69 and '70 C-150.
Good luck with a nice little plane.
 
I owned a 1976 150M for a bunch of years. One of my best investments was membership in the 150-152 Club. Lots of corporate knowledge of everything related to the 150. They have a flyin every year at Clinton Iowa just before Oshkosh that I used to attend. Go to https://cessna150152club.org/ and check it out. Membership is $35 a year and worth every penny if you're an owner.
 
Shimmy lot's of reasons, Easiest to fix, loose axel nut, tip the aircraft up and shake the nose gear, see what's loose.
Breather will always drip.
Check to see if all the screws are installed in the wing root panels, they will oil can when not.
 
I’m a former owner of a ‘66 F model. Join the C150-152 club. It is priceless. I miss that forum!

I fixed the shimmy by installed a McFarlane TL-KT-1 Torque Link kit with my A&P/IA observing. I removed the old bushings by actually tapping them and using a bolt, nut, and two sizes of washers to actually pull the old bushings out. They came out easy and there was no use of drills or cutting wheels or heat. Rebuilding the shimmy damper helps too. Only a few o rings and some fresh fluid.

To pinpoint the oil leak, pull off the cowling and after the engine is cool, take a cheap pump sprayer (1 gallon or handheld) and shower the engine area down with mineral spirits. Make sure the front end of the plane is over some visquene plastic to catch the runoff. Come back the next day and see what is going on. Roll it outside and start it up if you have to get the fluids to leak again.

Just like the others said, ALWAYS BE READY FOR CARB ICE! I lost my plane in a wreck a years ago due to severe carb ice on takeoff. I should be dead. See, I learned how to fly 24 years ago in an O-235 Lycoming powered C152 and a Rotax powered Katana DV-20 — so I never really understood how it can kill you. The Continental O-200 in your plane is a GREAT engine. The problem is that the “oil bladder/kidney” tank isn’t attached to the carburetor unlike the Lycomings. Thus the natural heat from the hot oil is not conducted to the carb to inherently keep it warm (carb’d Lycomings can still ice up but it’s extremely rare...)

Anyways, it was a cool 59 degree and humid July morning. I had a long taxi at the small airport due to fumble farting with ForeFlight. My buddy texted me and said he was on his way up with his young son to watch me takeoff so I waited a few more minutes. His witness statement says it best: “He took off. Leveled off for some reason. And then he disappeared.”

Engine was running at full power as I advanced the throttle but just sounded a TINY bit off. I rotated. Started to climb. I just couldn’t maintain altitude and was sinking. This is when the oh **** moment happened - WHAT DO I DO? I looked around, zero landing spots available except the runway in front of me. I nose dived it and massively forward slipped it. I landed it perfectly but was at like 110MPH. Brakes felt useless as when I looked behind me I saw two black stripes. Felt like I was on wet ice as the end of the runway quickly approached. I went off of the end and the rest is history. I literally **** my pants. No injuries except for my Levi’s.

Lesson here is that with the small Continentals, you REALLY do a carb heat function check AND a carb ice detection check. That means when you pull carb heat you really watch the RPM’s to see the drop (due to the rich fuel mixture with the thinner heated air) and you keep it there and watch for a rise in RPM’s as the ice is melting and the carb is warming up.

I’d get an ice detector and carb temp gauge if I was you.

Years later bought my Mooney and I told that story to the seller. He stared at me like he was seeing a ghost. Little did I know that his friend had just died in an accident two weeks prior due to to suspected severe carb ice on takeoff - it was powered by a Lycoming O-200...




Sent from my iPhone using Tapatalk
 
Chilito said:
First post, here goes:

I am the proud new owner of a '68 C150. Mid-time engine, great compressions, and flies like a dream, though I do have a couple questions, as someone who has most of his time in a 172.

1. Oil drips. I have read the O-200 is notorious for them. It drips after shutdown, and periodically. It hasn't been burning any more oil than usual. Sometimes more drips, sometimes less. I wipe it up. Normal?

2. Shimmy. Sometimes, when the yoke isn't held full back during roll out, I get a pretty good shimmy, enough to vibrate the dash and shake the panel plastic and instruments. Not all the time, but every couple landings. Dampener? Loose scissor? Maybe it's my landing? :)

3. Rattling noise on climb out - only noticed when tanks are full. Comes from the pilot's side, sounds like a seatbelt out the door, but it's not that. Everything seems to be secure, and it stops after about 15 mins of flight. Door seals? Antenna? Screw loose?

Thank you in advance.
Click to expand...
The small continentals are famous for leaking oil at both ends of the valve pushrod tubes. The rubber boots at the case end deteriorate or slip off their nipples a bit, or the clamps aren't positioned properly. If the leak is at the head, the tube needs re-swaging with a special tool. Rocker cover gaskets should be replaced with the red silicone aftermarket gaskets.

Nosewheel shimmy's root problem is dynamic imbalance of the tire/wheel assembly. Most nosewheels get no balancing at all, and the rest mostly get static balancing that often makes the shimmy worse. Some motorcycle shops have a dynamic balancer that can do a nosewheel. Replacing torque link bushings and fooling with shimmy dampeners is only hiding the problem for a few hours until the parts wear again because the wheel is still pounding them.
Rattling on climbout with full tanks might be the fuel level sender float rattling against the top of the tank. It's float arm stop isn't adjusted right and the float will wear a hole in the top of the tank. Expensive damage.
 
Dan Thomas said:
The small continentals are famous for leaking oil at both ends of the valve pushrod tubes. The rubber boots at the case end deteriorate or slip off their nipples a bit, or the clamps aren't positioned properly. If the leak is at the head, the tube needs re-swaging with a special tool. Rocker cover gaskets should be replaced with the red silicone aftermarket gaskets..
Click to expand...
I suspect it's just the mocha colored drip from the oil breather line. I keep a piece of cardboard below it in my hangar to catch the drips. But if you want to be done with pushrod leaks, get the REAL Gaskets mod. It adds a spring like the bigger engines and eliminates oil leaks. While you're at it get their valve cover gaskets that Dan recommended and be sure to no over tighten them. The other must-do with the C-150 is to lean. Lean on the ground, lean once you level off, lean in descent, etc. etc. Morning sickness (stuck valves) are a real possibility with the Conti O-200, I've seen more than one Cessna 150 at the 150-152 fly-in getting the rope trick because they run full rich all the time.
 
the Cessna single engine nose gear design has a linkage arrangement that forces it to center as it extends after liftoff. This centering defeats any shimmy linkage check and shimmy damper analysis when the nose gear is simply lifted off the ground by pulling the tail down.

Instead, let all the air out of the nose gear strut, allow it to collapse, pull or weight the tail down to lift the collapsed nosewheel, then allow a little atmospheric air into the strut to make it extend into its normal working area. NOW you can better evaluate the whole linkage for backlash and loose pivots etc to fix the whole system. Shims are available to control backlash.

Good time if necessary to replace seals and fluid. Recharge etc when done.
 
O-200 and O-300 oil leaks from the pushrod tubes are common. I used the STC'd Real Gaskets pushrod tubes and seals on the O-300-C in my '63 172D and it fixed the leaks. My current LSA's O-200 has less than 200 hours on it, but if the pushrod tubes start leaking I'll put the Real Gaskets tubes and seals on it.

For leaks from the breather tube, Cessna came up with a modified AN 842-10 elbow that has a brazed tube extending into the crankcase for use in the 150 Aerobat. Attached is an article that may help.
 

Attachments

  • Breather Tube Modification.pdf
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Stan Cooper said:
O-200 and O-300 oil leaks from the pushrod tubes are common. I used the STC'd Real Gaskets pushrod tubes and seals on the O-300-C in my '63 172D and it fixed the leaks. My current LSA's O-200 has less than 200 hours on it, but if the pushrod tubes start leaking I'll put the Real Gaskets tubes and seals on it.

For leaks from the breather tube, Cessna came up with a modified AN 842-10 elbow that has a brazed tube extending into the crankcase for use in the 150 Aerobat. Attached is an article that may help.
Click to expand...
The aerobat fitting doesn't always cure the breather drip.
I make them by the way.
 
Tom-D said:
The aerobat fitting doesn't always cure the breather drip.
I make them by the way.
Click to expand...
That's good, Tom; the price Cessna charges for them (part# 633182) is in the stratosphere. The last time I checked, they were charging north of $500! RMJ-Aero wants $190 (still pretty outrageous IMHO).
 
Friends,

Thank you for all of the tips and advice, and most of all, the welcome. Owning an airplane like the C150 has been a goal for quite some time, but now it is a reality.

The oil drips seem to only be after shut down, but they last for a day or two, slowly. Nothing after. Drips appear to be coming from the breather tubes...(there are two?)

I have attributed the flapping noise to the plastic door panel that is chipping away and now loose near the lock. Suggestions for that would be appreciated.

If anyone has more ideas about adding TCP to fuel, I'd love to hear. Worth it/not worth it?

Rob
 
Get the mogas STC and fill up with ethanol free gas or Swift UL94. A tank of 100ll here and there mixes in and won’t be enough to foul the plugs.
 
YooperMooney said:
<snip>

Just like the others said, ALWAYS BE READY FOR CARB ICE! I lost my plane in a wreck a years ago due to severe carb ice on takeoff. I should be dead.
<snip>
Click to expand...

I had a C-150 start running rough at about 400 feet on takeoff. I immediately pulled the carb heat and executed a turn back to the runway. RPM dropped to 2000rpm and I could just maintain altitude at Vy. At about the 180 point I had the runway made and elected to fly downwind at about 400 feet staying in position where I could easily land on the runway. About midfield downwind the RPM came back up and I could climb again. I landed did another good runup, Left the Carb heat on until I went to full power and did 3 more Takes-offs and landings with out incident. Lesson learned is the carb-heat took a while to take affect. Also it was Ideal Carb ice conditions, on the 1st take-off I had a couple minutes between doing the run-up and taking off where I am sure ice was forming, waiting until going to full power seemed to resolve any issues.

Brian
CFIIG/ASEL
 
I feel a carb temp gauge is mandatory equipment in a C-150.
 
Chilito said:
Friends,

Thank you for all of the tips and advice, and most of all, the welcome. Owning an airplane like the C150 has been a goal for quite some time, but now it is a reality.

The oil drips seem to only be after shut down, but they last for a day or two, slowly. Nothing after. Drips appear to be coming from the breather tubes...(there are two?)

I have attributed the flapping noise to the plastic door panel that is chipping away and now loose near the lock. Suggestions for that would be appreciated.

If anyone has more ideas about adding TCP to fuel, I'd love to hear. Worth it/not worth it?

Rob
Click to expand...

Advise on the interior panel.... put it in the weight loss bag...

I fly you predecessor the c140, I took my interior crap out, no carpet or upholstery besides seats, all of 15 lbs off her... With our useful load 15lbs is not insignificant... I painted interior, looks real nice just painted metal, cheap and relatively easy upgrade if ya ask me...
 
Does that new breather tube mod come with all new or factory rebuilt o-200's from continental?
 
Tom-D said:
Yes I still do them.
Click to expand...
Thanks, can you PM me or send me some contact info? I'd like to find how what the cost would be. But I still need my IA to tell me he's willing to sign off on it.
 
Suggest you do diagnostics before starting any repairs.

As stated ;you will want to check for looseness with the Nose Strut compressed.

I find it works well with weight on the Nose Wheel.

If you can stop the shimmy with UP elevator you are obviously extending the Nose Strut

The Centering CAm is a steel block on the Upper Torque Link that will lock the

steering straight ahead.

It also isolates the Upper Torque Link Upper pivot and down from the rest of the system.

Kind of hard to tell exactly but if you get shimmy with Strut extended it’s likely

in the Torque Links or Nose Wheel.

If back pressure does not stop it you need to look further.

A common offender is the Steering Collar that the Upper Torque Link attaches to.

If it rocks when checking for looseness it can be shimmed.

Requires removal on a Nose Strut to do so.

Not a big deal though.

My opinion is the primary means of controlling shimmy is the Steering Rods

that protrude from under the Firewall and attach to the Steering Collar.


These are Spring Loaded and will center the Steering System.


That is IF the Rudder/Nosewheel System is correctly rigged.

Stopping the Shimmy can be as easy as one or two turns on the adjustment.

Very easy to check and adjust BUT the Service Manual will detail.

Ignoring the problem can cost a lot more!!!
 
Magman said:
Suggest you do diagnostics before starting any repairs.

As stated ;you will want to check for looseness with the Nose Strut compressed.

I find it works well with weight on the Nose Wheel.

If you can stop the shimmy with UP elevator you are obviously extending the Nose Strut

The Centering CAm is a steel block on the Upper Torque Link that will lock the

steering straight ahead.

It also isolates the Upper Torque Link Upper pivot and down from the rest of the system.

Kind of hard to tell exactly but if you get shimmy with Strut extended it’s likely

in the Torque Links or Nose Wheel.

If back pressure does not stop it you need to look further.

A common offender is the Steering Collar that the Upper Torque Link attaches to.

If it rocks when checking for looseness it can be shimmed.

Requires removal on a Nose Strut to do so.

Not a big deal though.

My opinion is the primary means of controlling shimmy is the Steering Rods

that protrude from under the Firewall and attach to the Steering Collar.


These are Spring Loaded and will center the Steering System.


That is IF the Rudder/Nosewheel System is correctly rigged.

Stopping the Shimmy can be as easy as one or two turns on the adjustment.

Very easy to check and adjust BUT the Service Manual will detail.

Ignoring the problem can cost a lot more!!!
Click to expand...
Over many years I have replaced plenty of nosewheel steering stuff like torque links and shimmy dampers and all the rest. I have rerigged the rudder/nosegear system exactly as per manual. I have rebuilt the whole strut. I have dynamically balanced the nosewheel.

Out of all that, the dynamic balance is the ONLY thing that ever stopped the shimmy. I've done the balance on nosegears that have loose torque links and stopped the shimmy.

That's dynamic balance, not static.

Why do you think the tire shop dynamically balances your car's wheels when you buy new tires?
 
Dan Thomas said:
Over many years I have replaced plenty of nosewheel steering stuff like torque links and shimmy dampers and all the rest. I have rerigged the rudder/nosegear system exactly as per manual. I have rebuilt the whole strut. I have dynamically balanced the nosewheel.

Out of all that, the dynamic balance is the ONLY thing that ever stopped the shimmy. I've done the balance on nosegears that have loose torque links and stopped the shimmy.

That's dynamic balance, not static.

Why do you think the tire shop dynamically balances your car's wheels when you buy new tires?
Click to expand...
Do the whole job,, rebuild the strut, then balance the wheel.
 
Tom-D said:
Do the whole job,, rebuild the strut, then balance the wheel.
Click to expand...
If the customer will pay for it. I've done just the dynamic balance to prove that it works, and it highlights the fact that all the other stuff just masks the imbalance that is the real root of shimmy. There are many dollars spent on replacing and tightening this or that, and then having to do it again later on. It's like getting new tires on your car but not getting them balanced, and just replacing all the rod ends and suspension stuff every few years to try to get that steering wheel to stop shaking.

Imbalance on an airplane is much worse. The nosewheel fork, the strut and its attachment all have a certain amount of flex, and that feeds into the geometry of shimmy.
 
Dan Thomas said:
If the customer will pay for it. I've done just the dynamic balance to prove that it works, and it highlights the fact that all the other stuff just masks the imbalance that is the real root of shimmy. There are many dollars spent on replacing and tightening this or that, and then having to do it again later on. It's like getting new tires on your car but not getting them balanced, and just replacing all the rod ends and suspension stuff every few years to try to get that steering wheel to stop shaking.

Imbalance on an airplane is much worse. The nosewheel fork, the strut and its attachment all have a certain amount of flex, and that feeds into the geometry of shimmy.
Click to expand...
So do I just take the nose wheel down to the local motorcycle shop and ask them to balance it? How many shops usually have the necessary adapters, most of them?
 
Matthew Rogers said:
So do I just take the nose wheel down to the local motorcycle shop and ask them to balance it? How many shops usually have the necessary adapters, most of them?
Click to expand...
most of the well equipped tire dealers can balance small wheels.
 
Chilito said:
1. Oil drips. I have read the O-200 is notorious for them. It drips after shutdown, and periodically. It hasn't been burning any more oil than usual. Sometimes more drips, sometimes less. I wipe it up. Normal?
Click to expand...

drips from where ? the breather vent?
 
Dan Thomas said:
I've done just the dynamic balance to prove that it works, and it highlights the fact that all the other stuff just masks the imbalance that is the real root of shimmy.
Click to expand...
No balancing will fix a worn out strut.
 
Tom-D said:
No balancing will fix a worn out strut.
Click to expand...
Nope, but I have, as I said, stopped the shimmy on worn-out nosegears just by balancing that wheel. My point is that almost all shimmy gets addressed by replacing a whole bunch of expensive parts, only to see them get shaken loose again by that imbalanced wheel. It's crazy.

Small-wheel balancers are hard to find. Motorbike shops are the best bet. In the flight school I had an ancient all-mechanical dynamic balancer that I modified to take nosewheels. When I left to work elsewhere I looked for another one but since they'd all been built 50 or 60 years ago they were long gone. So I built my own. One can buy a small-wheel electronic balancer but they cost around $4K.

Before I had any balancer I did it by hand. Wash all the grease out of the bearings, put them in and run the axle in and hold pressure against the bearing spacers with both hands to keep the bearings seated and spin the wheel up a little by touching it to a wire wheel on a bench grinder. It will shake up and down (static imbalance) and it will wobble (dynamic imbalance). Using some small blocks of stiff foam rubber you place lead weights at various spots in the wheel and try again. Trial and error, and it takes a long time until you get the hang of it. When it's right it will spin with no shake or wobble. Once you have figured the weights and locations you clean off the metal real good and stick Goodyear stick-on weights in those places. Aviall sells the weights, if I recall right it's part number 9901, maybe. Regrease the bearings and put it all back together. I did this for years in the flight school before I found that old balancer, and the machine cut the time way down. It eliminated the trial-and-error stuff. And it was safer. Maybe I should have made a YouTube video.
 
More C-150 stuff....
I was discussing logs (with a friend) and what is supposed to them.

It was discovered the engine which had a pull starter had been changed to a electric key start.

The engine change was logged correctly. but no mention of the starter, or key.
this was 10 years from the entries.
 
So wait...if we are only required to keep the logs of the most recent annual inspection and AD compliance, why are older entries even necessary? Other than the airframes that have specific ADs that must be complied with in the past or life limited components. For the C150, I think most if not all the ADs are the annual inspection ADs. So other than 337s on file in OK and the most recent inspection in the books, what is actually required to kept in the logs past one year? If you lose older logbooks, it does not matter, so you could lose the old book every year just before the annual and start a new one and technically be in compliance, right?

what am I missing? A lot probably.
 
Matthew Rogers said:
So wait...if we are only required to keep the logs of the most recent annual inspection and AD compliance, why are older entries even necessary? Other than the airframes that have specific ADs that must be complied with in the past or life limited components. For the C150, I think most if not all the ADs are the annual inspection ADs. So other than 337s on file in OK and the most recent inspection in the books, what is actually required to kept in the logs past one year? If you lose older logbooks, it does not matter, so you could lose the old book every year just before the annual and start a new one and technically be in compliance, right?

what am I missing? A lot probably.
Click to expand...
Good books saves a lot of time.
each year the IA must comply airworthiness In accordance to part 39. some of the ADs are really old.
incomplete entries leaves us wondering if the proper parts are installed.
The 150 I just saw has no way to telling if the aircraft is properly configure. model says it is a pull start, but it is a key start. So what do we do?
 
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