Shop Discount Sea-Doo Parts

Marvel Mystery Oil - what do you use it for?

IDoSeaDoo

Well-Known Member
Messages
3,032
Location
Davie, Florida
Water Crafts
1995 Sea Doo XP800 (future project)
2009 Yamaha FX HO
1997 Seadoo Challenger 4tec
Does Marvel Mystery Oil still have a place in the modern garage? what with synthetic oil and fuel injection, I'm not sure how or when I'll ever use my supply of it. I bought some to free up some seized pistons a long time ago and still have it laying around. Recently, I came into a gallon of the stuff. I own a new turbo-diesel truck and a lexus hybrid as well as a slew of jet skis and other small 2 and 4 stroke motors. What can it help me with?
 

noviceskier

Active Member
Messages
425
Location
Tennessee, Knoxville
Water Crafts
96 Seadoo HX
96 Seadoo HX with FPP
96 Kawasaki sts 750
Does Marvel Mystery Oil still have a place in the modern garage? what with synthetic oil and fuel injection, I'm not sure how or when I'll ever use my supply of it. I bought some to free up some seized pistons a long time ago and still have it laying around. Recently, I came into a gallon of the stuff. I own a new turbo-diesel truck and a lexus hybrid as well as a slew of jet skis and other small 2 and 4 stroke motors. What can it help me with?
I just use it to free up locked motors that have been sitting in fields for years, nothing else really, although transmission fluid works with that too. Although I could try it on some seized bolts but pb blaster and heat do it just fine.
 

mikidymac

Moderator
Staff member
Moderator
Messages
12,306
Location
California
Water Crafts
2003 GTI
2001 XP
1996 XP
1996 HX
1991 Superjet
2001 Superjet
Honestly I have never owned it or SeaFoam or Snake Oil.
 

AKnarrowback

Well-Known Member
Messages
551
Location
Fairbanks Alaska
Water Crafts
94 xp
94 sp
94 gtx
Incense.

When I want my garage to smell like pepto bismol I light up my wifes potpouri candle and pour some MMO in the dish.
 

etemplet

Premium Member
Premium Member
Messages
2,732
Location
Louisiana
Water Crafts
1996 SPI, 1996 GTX, 1997 GTX
This is good stuff to use for pouring into the carbs to clean the top of the engine and loosen deposits. Lots of people used to d this way back when to keep their carbs clear. It is also good to put in the fuel to lubricate the top end. In our aircraft it is great to put into the fuel to keep the valves lubricated. Probably be good as a tapping or honing oil. I'll bet it is good for lubrication of air tools, and any place a light oil is needed or warranted. As you mentioned it is good for freeing up frozen or stuck devices. Good Stuff !!

Put it in your mower fuel, maybe a little in the engine bottom and just before you change the oil. Of course.... some people don't believe in it at all. A buddy of mine that has the same aircraft engine as me is fond of posting, "there are two types of Cessna 150 owners, those that have engine valve problems and those that use Marvel Mystery Oil."
 

IDoSeaDoo

Well-Known Member
Messages
3,032
Location
Davie, Florida
Water Crafts
1995 Sea Doo XP800 (future project)
2009 Yamaha FX HO
1997 Seadoo Challenger 4tec
how does it lubricate the valves? You mean like the valve stems/guides? Very interesting... I always thought oil lubricates that, but I guess not as the valve stem seal would prevent that...
 

etemplet

Premium Member
Premium Member
Messages
2,732
Location
Louisiana
Water Crafts
1996 SPI, 1996 GTX, 1997 GTX
Since MMO goes into the fuel it lubricates the top of the piston and the valve stems. I think is softens the deposits already there. Continental 0-200 engines are known for valves sticking. It isn't an approved additive for aircraft. It goes back to World War II. :) and there are mechanics today that learned from those guys. When I use it in my plane and I can tell the difference. Our engines were designed to use leaded fuel which is no longer available.
 
Last edited:

mikidymac

Moderator
Staff member
Moderator
Messages
12,306
Location
California
Water Crafts
2003 GTI
2001 XP
1996 XP
1996 HX
1991 Superjet
2001 Superjet
I thought Av Gas was LL or Low lead but not no lead?
 

etemplet

Premium Member
Premium Member
Messages
2,732
Location
Louisiana
Water Crafts
1996 SPI, 1996 GTX, 1997 GTX
100LL doesn't have enough lead for the Continental 0-200 that was designed to run 80/87 Octane leaded fuel which is no longer available.
 

Users who viewed this discussion (Total:17)

SPONSORED LINKS

Usergroup

Administrator Moderator Premium Member
Top