Marvel Mystery Oil

[Summershandy]

I was picking up some odds and ends and found that MMO is available where I live. I've read about it and stuff so I thought I'd pick up a bottle. The weather is warming up so I took the car out of it's storage and gave it a going over. Everything's still looking good. I added some MMO to the fuel and crankcase. Took it for a short ride around the block and parked it. Left it over night and started it up today. Ran like total crap! I had about a 1/4 tank of gas from last fall and I know you can get bad gas but I couldn't even give it 1/2 throttle without any rpm change. Just sat there sputtering and shaking. I filled the gas tank with what ever gas I had in the garage, maybe a couple gallons but ended up killing the battery trying to get it started again. I'll try again tomorrow when the battery's charged but running like this I doubt I can even make it to the gas station. Never had the engine run this rough before. Never been a fan of additives and you know the old saying, when something ain't broke......

[JFranklin]

It wasn't the MMO that caused your problem if used as directed. I bet it was the old gas.

[Grimy]

How much MMO did you put in your 1/4 tank?  And how was it supposed to mix with the gas?  In my side valve engines, I use 4 oz MMO per 10 gallons, about every other tank, and have been known to double-dose the first tank in tour season because that's when valves seem to want to hang up..  But it's essential to mix with the gas--by (first) adding MMO and (then) stick the nozzle in the tank and let the new fuel under pressure mix it up.

 

I suspect that the MMO, heavier than gasoline, sank to the bottom of the tank where the fuel pickup is located, so your mix is horribly rich in MMO.  I suggest you go top off the tank, and run the first 5 gallons in at the highest pressure you can--full squeeze on the nozzle.

[Summershandy]

10 hours ago, Grimy said:

How much MMO did you put in your 1/4 tank?

I'm guessing about 6 ounces but I think you're right. I had more smoke coming from the vent tube then normal. I too wanted to give the engine a good dose but like you said, I'm probably the richest I've ever been!

[Summershandy]

12 hours ago, JFranklin said:

I bet it was the old gas.

I had already ran the car around the block a couple times with no issues. I have read bad gas can really foul up an engine. I treat all my engines with seafoam before and after the storage season. 

[Summershandy]

Sputtered 15 mph to the gas station and filled up. Sputtered 15 mph back home.....no difference. 

Time to pull the plugs and been meaning to change the fuel filter this year too. I'll start there. 

Can't believe how bad this stuff altered the engine. 

[Summershandy]

If anyone is interested in lessons on being a bonehead....just message me.

I had failed to mention that during this episode, I decided to check the points. Haven't looked at them in 2 years since new. Nice and clean with no pitting. Gap seemed to be a little tight so I adjusted them. Maybe I didn't have them perfectly on the cam but I went back in and rechecked and the gap was too wide. I took more time to be careful and got them spot on. I would have never believed just a little change in the gap would make the engine run like total crap! 

It's purrs like before and has lots of pep during cruise. MMO is off the hook!

Oh, and thanks to Grimy....I now have a full tank of gas. 

[Grimy]

@Summershandy as to point gap:  If the rubbing block on the points is nylon, I set NEW points at least .001 wide, maybe .0015 wide, to allow for wearing-in during the first thousand miles.  For older vehicles and NOS/NORS points with fiber rubbing blocks, add another .001 to the initial setting for the greater wear anticipated.  The fiber rubbing blocks seem to need checking for proper gap about every 5-6,000 miles.

 

And for another goose-grease additive to stabilize fuel, I prefer to use "Startron" from a marine supply house over the winter or if it will take over 4 months to go through a tank of 10% ethanol fuel.  The Startron is enzyme-based, dosage 1 oz per 8 gallons, seems to last longer than even marine (blue) Sta-Bil.  Like MMO, pour the additive in the tank just before the gas nozzle to properly mix the additive.