Marvel Mystery Oil in Motorcycles???

Question

(Skip to last two sentences if your not interested in Motorcycle type and reason for this question)
I recently purchased a 1982 Honda CB650SC (Nighthawk). It's a wet-clutch, so as I understand it the engine oil also works as lubrication for the transmission as well. This being an older bike, I figure some sludge and carbon has built up in the engine because most people dont perform maintenance like they should. I was going to add Marvel Mystery Oil to the engine oil once or twice to clean it out and then just go with full synthetic all the way. Sorry, but I am not interesting in opinions as to weither or not MMO will do anything at all. I am just wondering if a small amount of MMO (0.3 quarts MMO to 3 quarts of oil) will be safe in a wet-clutch motorcyle?

Specs?
1982 Honda CB650SC (Nighthawk)
SOHC- 2 Valves Per Cylinder
650CC (actually around 627CC)
5 Speed Manual (Clutch) Transmission
Four Cylinder Engine (4-Stroke)
9500 RPM Redline
17,515 Miles
That's probably the best specs I can give ya.

Answer 1

the only way to properly clean out an engine is to do a complete rebuild. any other 'fixes' is a waste of money. 25 year old bike....treat it good, and it will perform just as well now as it did back then. oil additives are a complete waste of money.

Answer 2

Aug. 5th 2015, my new to me (24k on motor) 97 Honda nighthawk 750 received barely 2 cap fulls of MMO in engine earlier today. Shifting into 1st gear rather difficult at ONLY at standstill. Thought I would try running 20-30 miles then drain. Tonight on the way home it seemed to be just a tiny bit better. Yeah, yeah, yeah.. I know, its all BS because oil additives dont do anything...OK whatever you say chief. :)

Critics and naysayers abound but it IS true that some bikes have clutches that are adversely affected by full synthetic oil. BEWARE
It happened to me, 78 Yamaha XS 1100 one of the burliest bikes ever made.
Ran and shifted faultlessly up and down the West Coast a dozen times passenger included at times. SF to Minneapolis and back, rock solid all the way...then I made the huge mistake of installing full synthetic oil. :(
Clutch never the same again.

Answer 3

Mystery oil in that amount won't hurt. It won't help much, either. As another poster noted, The inside is usually pretty clean. Just fill with fresh oil, add MMO if you want, run it for a bit, and drain. If you've got a lot of stuff in the oil, you need mechanical repair. If not, re-fill and ride. I don't think you'll see much of a benefit from synthetic oil.

Answer 4

hondas r awesome bikes i have had at least 12 hondas (dirtbikes)they were all great bikes and very reliable and i own a honda cbr 954rr street bike and it is a great bike. you will probably not have any problems even if it does have a little sludge it is kind of normal if it has some miles on it. just change the oil like your suppose to good oil isnt real cheap but it is reasonable go to a honda dealer and get the good stuff and the marvel isnt going to help it is more for air tools but any oil works in air tools and a jap bike will basically run on any motor oil

Answer 5

i would not use it in the engine its doubtful there is any sludge in the motor with the oils today. change the oil and filter there are detergents in new oil. if ifs black in a few days of the change then you know you have some sort of a problem as far as carbon marvel wont do a thing the only places you will have carbon build up is on the top of the pistons and the back of the valves and marvel wont get there from the crankcase oil

Answer 6

Most of the information that I have seen says NOT to use additives such as DuraLube. Reason being, even though it is a wet clutch, it needs some friction to lock it up. Super slippery oils may cause some slippage problems.

I would think that the same applies to MMO.

Drain the old oil and start using synthetic.

Answer 7

What are the specs? It's a 'craps shoot'. You'd be better of going straight to a syntec oil from the start. The only other advise would be a tear-down, and it's too late for that, unless you want to miss some early season rides.

Answer 8

What your proposing will not do ay harm. You are effectively thinning out the oil. This is normally recommended for a newly rebuilt or a new engine but as far as causing any damage, I would think not. I would not leave that stuff in too long.

Answer 9

That's a question for the manufacturer of Marvel Mystery Oil!
Aftermarket additives do more harm than good for the most part!

Answer 10

if the previous poster had a brain she would know it is an additive and works great when used in conjunction with your regulr oil in your crank case! just pour a small amount in not a lot not a little hard to describe.