Soft Cylinder

[N96290]

I have been busy and the wind was not friendly, well you know, it has been a couple of months since I have been out so today was the day to polish off some of the rust. The old 65 started the first blade but didn't run too smooth. I ran it up and 1400 was all she would make so I shut it down and felt the cylinders. The right front was cool and pulling it through one cylinder had no compression. I pulled the rocker cover and found a valve stuck. I worked it back out, but it still is way down on compression on that cylinder. I didn't run it up again, it might have been a little better and suckered me into trying it so I closed up the hanger and am going to get some professional help, for the airplane. It was too late for me 30 years ago when I bought my first airplane. Anyway is there anything I am missing and a easy fix for this ailment.

[M Towsley]

Re: Soft Cylinder

I stuck a valve on my former L-2 because the owner before me used 100LL exclusively for fuel and it had a lot of deposits. Ultimately the valve was dropped into the cylinder and the valve guide cleaned out. Your valve may still not be seating completely or is still sticking open. Other than that, no idea.

[magman]

Re: Soft Cylinder

I think what you're looking for is "the Rope Trick".

1. Remove plugs

2. Remove rocker Arm on "sticky".

3. Pack rope into the cylinder

4. Rotate crank until rope is pushing valve CLOSED

5. Depress Valve Spring Washer & remove keepers


The valve can be pushed into the cylinder & poked out the plug hole & cleaned.

The guide can be reamed or cleaned with a split dowel & sandpaper.

Be careful no metal is removed.

clean , lube & reassemble per TCM Manual.

This is NOT "Preventative Maintenance) & a "P" is required.

[flyguy]

Re: Soft Cylinder

Just had a thought reading this MM. How about a rifle bore brush and some kind of solvent for cleaning the guide?
DC

[Guest]

Re: Soft Cylinder

Just had a thought reading this MM. How about a rifle bore brush and some kind of solvent for cleaning the guide?
DC

Yep- that's what I did to my a65 with nearly stuck exhuast valve Daryl.

I Can't remember the bore size that I used but a rifle bore brush, one length of cleaning rod in a battery drill and it worked great.

It removes carbon, not metal so that is good.

I can't recall what I used for solvent, may have been wd40, "blaster" for stuck bolt but it wasn't Hoppes!

Dave

[Marv]

Re: Soft Cylinder

I had that happen to a BC12D 65 i had. I removed the valve cover and kept squirting Marvel Mystery oil on the valve stem and turning the prop back and forth till the valve was loose. I then put a teaspoon of MM oil in the cylinder and started it. I added MM oil to the fuel tank and taxied it around and seemed ok so i flew it and from then on i added MM oil to each tank of fuel. I flew it 2 or 300 hours after that before i sold it and never had any trouble. Marv

[magman]

Re: Soft Cylinder

Hoppe's #9 is used for cleaning Fuel Injectors & Primer fittings.

May work to clean a guide also.

[M Towsley]

Re: Soft Cylinder

Lyn,

Doesn't have to be a rifle bore brush but a pistol-sized one will work, too! This was done to mine, attached to an electric drill. To get the valve back into the cylinder run a string/monofilament line down the valve guide and work it out of the spark plug hole. While you have the valve stem out of the plug hole tie the string to it, drop it back into the cylinder and pull it back into the valve guide carefully. Obviously not a lot of room to work around but it can be done given time and patience. I ran Mogas almost exclusively after that with MMO and never had the problem again. When I would visit another airport away from home I would get 100LL just to mix it up a little. Good luck!

[N96290]

Re: Soft Cylinder

I got to wondering last night if the A65 has hydraulic lifters. I did not see any adjustment on the rocker. Could have been that the lifter was pumped up and had not bled back to let the valve seat. I will have to check it out again and see if the compression has came back. I had an O320 in my TriPacer that would get sticky valves if MMO was not used faithfully with 100LL. Yes This plane has been fed 100LL until the last tank full and no top lube as far back as I can tell. I am going to get my AI involved tomorrow but just trying to figure out a plan of attack. Likely will have to clean the guides but I can hope yet.

[magman]

Re: Soft Cylinder

The A-65 DOES have Hydraulic Lifters.

You can get an idea of "Dry Lifter Clearance" by turning the prop (Ign leads removed) until the valve is open.

Wait 5 min (?) & turn prop to allow valve to close.

Hold your thumb on the pushrod end of the Rocker Arm to keep lifter compressed.

I think clearance is .030 to .110 in.

Refer to TCM Manual on this.

If you remove the Rocker Arm you MUST ASSURE that the "Lifter Cup" is in the proper position.

Failing to do so may well lead to splitting the case.

It is NOT Prevent Maint & a "P" is required.

[freightpilot27]

Re: Soft Cylinder

I think clearance is .030 to .110 in.

Refer to TCM Manual on this.

Magman is correct. Those are the correct clearances. BUT its not in the A65 manual.
It's in the O-200 manual.

[Bird]

Re: Soft Cylinder

As a side note and I mean really side note-the use of mercury in a gun bore will clean and strip the barrel cleaner then anything else-but then again it is toxic (old marines trick)-and I just happen to have over 30lbs of the stuff--it came out of torpedo's it was found inbetween some false walls on the USS Intrepid-I use it in my quest when lookin for gold

[magman]

Re: Soft Cylinder

Magman is correct. Those are the correct clearances. BUT its not in the A65 manual.
It's in the O-200 manual.

Actually we are BOTH CORRECT!

The O-200 is .030-.110.

My OFFICIAL "CAA Copy" of the A-65 Manual states the same as well!

[Guest]

Re: Soft Cylinder

Hoppe's #9 is used for cleaning Fuel Injectors & Primer fittings.May work to clean a guide also.

I didn't know that.

Ahh... the smell of guns and planes combined into one. Life is good.

Dave

[N96290]

Re: Soft Cylinder

Thanks for all the info and I will let you know what my AI suggests and does. I do feel better now but maybe that is a false sense of hope.