Gas to oil mix

Michael Vogt /

Hi, i am new to this forum and i need help.

I found a vepsa bravo moped I think a (70's) model a the local junkyard and bought it, got it home and got it runing

Now here is the problem. I got it runing but the engine has no power and it smokes. I think that it may be the gas mix that I am using. To be safe not knowing the ratio, I am using a 16:1 mix. Could this be the problem? and also could you recomend a gas\oil mix. Thanks for any help you can give me. Thanks, Michael.

Re: Gas to oil mix

Allen Murphy /

Run 32:1 mix,and do that after you change your oil-soaked spark plug!

Beter yet, run the 32:1 until the smoking clears, and THEN change the plug!

Too much oil will make it burn too lean and burn up an engine in no time, so don't run it any further until you get this situation remedied.

Al Murphy

Re: Gas to oil mix

i agree it's best to not run a junkyard jewel 'till you have examined it and can be sure running it will not do serious damage.. and 32:1 is pretty safe for now.. it's mid range of oil recommendations.

Some (race) bikes might go with more oil, like 16:1 but fuel:air mix would be adjusted accordingly. (oil takes the place of gasoline.. so you burn less gasoline per pound of air.. that means "lean" mix)

another thing to consider is it might smoke for quite a while.. the exhaust could be filled with the goo and must eventually burn off. Beyond being full of residue the exhaust is often clogged with carbon buildup which might explain the poor, low power running.

Part of the examination should include removing the head and exhaust pipe and scraping away any carbon buildup.

Re: Gas to oil mix

Steamboat Aka J. R. Stevens / Idon't understand how adding too much oil is going to burn up an engine when the excess oil is going to slow down the flame front during combustion and oil does much of the cooling by reducing friction.I leave that to the engineers but the above link to Amsoil and their 100:1 mix blows my mind. comments please.

Re: Gas to oil mix

a little trick for testing the effects of a smaller main jet is to add more 2-stroke oil to the mix. It makes the bike run leaner.

At what point does adding oil no longer lean the mix? By definition there is no such point. More oil = less gasoline mixed with some constant amount of air.

At what point do the side effects of too much added oil prevent the possibility of damage due to a lean mix? I guess you have to test it and find out.

I'd guess there are at least two reasons Amsoil can make the claims it does.. First off they are not talking about 25 year old moped engines. Secondly they are trying to sell a product.

Their resoning is that since there are no solvents in their oil, you can use less.. However logically speaking, if there are no solvents you are not necessarily using less.

Lets say..

A 50:1 oil-type is half solvents and you need 1 ounce. (1/2 ounce is oil)

If you remove the solvents and go 100:1 you need 1/2 ounce.

So you are using 1/2 ounce of oil in either case.

If you trust them enough to use their oil at 100:1, be my guest and please report back here with the results.

Re: Gas to oil mix

too much oil doesn't do anything to an engine except carbonize everything. It just a real pain to clean out your cylinder/piston/exhaust. as a general rule of thumb, better more oil then less.

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