Anyone ever have any luck using Marvel Mystery Oil? I have a sticking intake valve and have been told to try the oil. Let me hear from you.
Ken Nesbitt N3407D
Marvel Mystery Oil
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Sticking Valve
The best option is to take it to an A&P and have them ream the guide and clean the valve stem. It can be done without taking off the cylinder for about 2 hrs labor. The spark plugs are removed along with the valve cover. The rocker arms removed and the valve spring removed. The valve can then be dropped into the cylinder and the guide reamed. The valve steam can be cleaned by pulling it through the spark plug hole then one can clean off any buildup.
Chemical products may help prevent or prolong the time before a valve sticks, but not fix them after they begin to show symptoms of sticking.
Chemical products may help prevent or prolong the time before a valve sticks, but not fix them after they begin to show symptoms of sticking.
Re: Sticking Valve
How do you guide the free floating valve which I presume is just laying on the cylinder wall back up thru the guide?N1277D wrote:The best option is to take it to an A&P and have them ream the guide and clean the valve stem. It can be done without taking off the cylinder for about 2 hrs labor. The spark plugs are removed along with the valve cover. The rocker arms removed and the valve spring removed. The valve can then be dropped into the cylinder and the guide reamed. The valve steam can be cleaned by pulling it through the spark plug hole then one can clean off any buildup.
Chemical products may help prevent or prolong the time before a valve sticks, but not fix them after they begin to show symptoms of sticking.
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Bruce Fenstermacher
- Posts: 10320
- Joined: Tue Apr 23, 2002 11:24 am
This can be done rather easily with some helper guides made out of saftey wire.
First you need a small light that you can put through a spark plug hole. I took a mini mag light bulb and soldered wires to it and attached this to a battery pack. This works great for a lot of things.
Then take some saftey wire about 15 inchs long. Form a y in the middle and twist the rest together to make it stiffer. the Y forks at the end need to be a bit longer than a half inch. Form the Y in a shape that you can snap over the valve stem yet it will slide up and down on the stem. You will need two of these Y tools.
After cleaning the valve and guide insert the light in the top spark plug. Insert the y tools in the bottom spark plugs and viewing the inside of the cylinder through either spark plug hole or the valve guide, snap the y tools on to the valve. The valve can then be lifted up into position and in some cases inserted back into the guide with the Y tools alone. Most times you get the valve in position and very very gently push the valve back into the guide with the piston. DO NOT FORCE ANY THING.
I have done this to my C65 in my Cub in about 20 minutes total but I had done it before.
The first one takes some time to figure out, buy the time you get to your sixth cylinder you'll be a pro. If you need a picture of the Y fork tool I could make one and send a pic to you in a few days if you email me privately.
Buy the way you can use a length if 3/8 plastic of rope inserted through a spark plug hole and compressed VERY VERY carefully buy the piston against the valves to hold the valve in will removing the valve spring. And although a valve spring compression tool is nice to have I have compressed the valve springs VERY VERY carefully with nothing more than two screw drivers.
This whole proceedure is locally called "The Rope Trick" and is actually outlined in a Lycoming SB which is how I learned it.
And yes I've done an emergency cleaning when a valve stuck on a cross country with my Cub with nothing more than a tie down rope, two screw drivers, a small brass drift and hammer to remove the stuck valve and a razor to clean the carbon. I used a piece of copper tube small enough to fit into the valve guide with the end sharpend to VERY carefully scrape the carbon from the valve guide. The locals watching were amazed till the old timer showed up and wondered what was taking me so long
I don't mean to make this sound overly easy but it's just not hard if you are a competent mechanic. If your not, get help.
First you need a small light that you can put through a spark plug hole. I took a mini mag light bulb and soldered wires to it and attached this to a battery pack. This works great for a lot of things.
Then take some saftey wire about 15 inchs long. Form a y in the middle and twist the rest together to make it stiffer. the Y forks at the end need to be a bit longer than a half inch. Form the Y in a shape that you can snap over the valve stem yet it will slide up and down on the stem. You will need two of these Y tools.
After cleaning the valve and guide insert the light in the top spark plug. Insert the y tools in the bottom spark plugs and viewing the inside of the cylinder through either spark plug hole or the valve guide, snap the y tools on to the valve. The valve can then be lifted up into position and in some cases inserted back into the guide with the Y tools alone. Most times you get the valve in position and very very gently push the valve back into the guide with the piston. DO NOT FORCE ANY THING.
I have done this to my C65 in my Cub in about 20 minutes total but I had done it before.
The first one takes some time to figure out, buy the time you get to your sixth cylinder you'll be a pro. If you need a picture of the Y fork tool I could make one and send a pic to you in a few days if you email me privately.
Buy the way you can use a length if 3/8 plastic of rope inserted through a spark plug hole and compressed VERY VERY carefully buy the piston against the valves to hold the valve in will removing the valve spring. And although a valve spring compression tool is nice to have I have compressed the valve springs VERY VERY carefully with nothing more than two screw drivers.
This whole proceedure is locally called "The Rope Trick" and is actually outlined in a Lycoming SB which is how I learned it.
And yes I've done an emergency cleaning when a valve stuck on a cross country with my Cub with nothing more than a tie down rope, two screw drivers, a small brass drift and hammer to remove the stuck valve and a razor to clean the carbon. I used a piece of copper tube small enough to fit into the valve guide with the end sharpend to VERY carefully scrape the carbon from the valve guide. The locals watching were amazed till the old timer showed up and wondered what was taking me so long
I don't mean to make this sound overly easy but it's just not hard if you are a competent mechanic. If your not, get help.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Ken, I use MMO at the proper ratio in each tank of fuel....mogas or avgas. Likely will not do enough to help you with the valve that is already stuck, but I think it is a good "preventative" measure. I don't recall anybody ever having a stuck valve after using MMO for a while. I'm going to try a bit of MMO in the oil as well just before next oil change to get at the valve stem from the other end. Another reason to get your "slightly overpriced" copy of the Association SRAM...the procedure for removing and cleaning the valve stem and guide is detailed in the SRAM...so no need for it to be repeated here...but of course no way for you to know that until now. I'm glad I finally got my SRAM, as it answered many questions that I would have had to bring to this forum otherwise.
John, 2734C in Summit Point, WV
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rudymantel
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- Joined: Sat Nov 23, 2002 4:03 pm
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funseventy
- Posts: 230
- Joined: Fri Oct 25, 2002 11:46 pm
After you fix this one. you should run the engine harder and lean more aggressively. We all need to run them hot enough to burn of the lead. Sometimes what we call "babying the engine" really hurts it more.
I've got a lot of time with O-300's and I don't have any problems. I just run the snot out of them! It will save you money over the long term.
Kelly
I've got a lot of time with O-300's and I don't have any problems. I just run the snot out of them! It will save you money over the long term.
Kelly