Is it good stuff? I know the old-timers swear by the stuff. I did a search on here, though, and read a couple horror stories. I would use Seafoam, but I'm paranoid of it too. Another horror story, involving a relative's diesel tractor. Still a bit afraid of it, though. But anyway. Is MMO ok to put in the gas tank, as a fuel injector/fuel system cleaner. I've used it in carbed engines before with no issues, but I'm not sure how fuel injectors handle it. I know it seems to clean more gently than Seafoam, and I don't have massive clogs or anything, so I thought it might be better. I've used all kinds of dump-in fuel injector cleaners, even the good stuff, and it never seems to make a difference. My Subie isn't running bad, but she doesn't idle as smooth as she used to, and power is down a bit. You can't schluck MM down the intake like Seafoam, though, can you? I know it seems a bit oiler. I'm planning a plug and wire change soon, too, as it's way over due. I don't know when (if? ) the P.O. changed them.

 

Read up a bit on Seafoam...It kinda sounds more like what I want. Which do you guys think is better? Seafom or MM?

 

Anywho...whatcha think?

 

Thanks for your opinions.

'93 Impreza, 193k mi.

I've used it both the fuel tank and the oil. Haven't had any problems with it, but I couldn't tell you that it solved all my problems, either. I definitely haven't considered using it like Seafoam, sucking it down the intake... not sure I'd want to.

MMO.....in my opinion and experience, is one of THE single most useful things to have on hand, second only to duct tape and zip ties.

 

I have used it in the gas, the oil, and also straight down the intake.

 

OK.... You warm your motor up, then remove your air cleaner.

With one hand on the carb to throttle it up, you begin slowly pouring your MMO in.

Huge clouds of smoke will follow (the MMO burning) and you increase the throttle some as it bogs down from burning Marvel instead of gas.

 

After a minute......you stop and shut it off. Let 'er sit overnight, and in the morning, after the MMO has had time to dissolve all that gunk, your subie will run like its 1986 again! Theres nothing better.

NO ill affects!

 

**edit** You MAY want to consider doing this in a non-city setting....as it produces TONS of smoke, and someone next door may very well end up calling the fire dept. on you!