National Aeronca Association Bulletin Board

How many people are using MMO to get rid of the lead in 100LL, and are you using it in just the gas, or also in the oil.
I've been using just 100LL and in about 120 hours last year had to dig out the plugs at annual but otherwise no problems. And I don't want any either.

Been using it forever in the gas 4-6 ounces per 10 gallons. Haven't found a need for it in the oil. I run Phillps 20W-50.

Doug

Likewise have used it for many years in the gas haven't used it in the oil. I use 100LL in my 0-200 exclusively even though someone got an auto gas STC on it, also use TCP as long as my supply lasts, at the annuals there is minor lead deposits to remove from the plugs very very minor. I also have fine wire plugs less problems with lead deposits and much easier starting in cold temps and they last for ever (well almost ).

I'm not sure putting it in the oil does much good as it's so light it probably flashes off or vaporizes once the engine is up to temperature. At least that's what I read (and who am I to argue). I use Phillips 20-50 XC also which seems to work well so don't see any need for additives. If it were necessary I think the oil manufacturer's would put it in there as part of the additive package. Whatever we're using for oil now is far superior to what was available 30-40 years ago. I pretty much use auto fuel so lead is not a problem unless I'm doing some cross country and auto is not available.

Mike Berg

Holcombe wrote:How many people are using MMO to get rid of the lead in 100LL, and are you using it in just the gas, or also in the oil.
I've been using just 100LL and in about 120 hours last year had to dig out the plugs at annual but otherwise no problems. And I don't want any either.

Actually, I don't think MMO was ever intended to be a lead remover for 100LL. I use it, but in the fuel as a top cylinder lubricant and don't use it in my oil. As others have said, I don't think modern oils need any help. I use XC20W50. I also use auto fuel...as long as I'm still able to get some without ethanol. So lead isn't an issue with it.

As well I use it as an upper cylinder lubricant. Used it for years and Aeronca actually recommended it in their early engines.

I use it in the gas. Have also used it in the oil on occasion. Read somewhere that if you put some in the oil about 5 hrs before oil change, it helps clean the gunk out of the engine, which then goes out with the old oil when you drain it.

All of the seasoned antique'rs out West use it. I have used it for years and have not had any valve related problems.
When I purchased my KCA it had been in the back of a hangar for 30 plus years. Once I got it running the lifters would not pump up. After about 30 minutes it was still noisy. I added 1qt of Marvel to the oil and within 5 minutes it was quiet. You could hear the engine quiet down each minute it ran. I don't know the science behind the stuff but I'm certain it works. Some things you have to take on faith.
Paul

It's a "mystery" . Agree that adding some to the engine oil before a oil change might help clean out the gunk. Basically, I think it's somewhat akin to automatic transmission fluid and a super cleaner. Certainly would help clean the gunk out of the hydraulic lifters as Paul stated. My only concern with adding it in a large amount to the oil would thin out the viscosity too much and possibilty pound out the bearings after a period of time.

Mike Berg

Brian ashless dispersant oil (AD) will do the same thing to an engine that has run on mineral all its life--it really loosens up the gunk . Alot of old timers wouldn't use AD oil when it first came out.

Doug

I agree, the stuff is wonderful for a cranky engine, but for daily operations, I only run it in the gas; 4oz./10 gal.
I'm always afraid it could loosen a glob of carbon, plug a galley and smoke a bearing, if I run it in the oil.

nkh

Nathan,

Four ounces per gallon? Thats a lot when you are putting in 15 gallons or so per fillup IMHO. I put 4-5 ounces in the tank then fill it up and have had it work well in this manner.

You own stock in MMO?

Joe

sorry...

4oz/ 10 gal

nkh

I used it for years and am going to start again. Former lead mechanic for 40 years says its great to use as gas additive. He likes straight 50 wt. in summer, 20-50 winter. He claims 1930's technology that we are running likes straight weight oil. I'm intersted to hear what all of you think. (Earlier in his career he rebuilt ALOT of small engines like 65 to 100 hp.) thanks JP

Guess I can't understand why he wouldn't run 20-50 all year long, but one things I've figured out over the years is that nothing seperates any two mechanic's thinking like engine oil. My AI says Phillips 20/50 is not good . He likes Aero Shell. I've used Phillips 20-50 for over 25 years in both my 65's and my Cherokee 140 with zero problems. Of course, he doesn't like auto fuel either.

Go figure................... .

Mike Berg