petrol mixing ratios

i just purchased my first moped (77 Puch Newport, woohoo) and have a question about mixing petrol.

i've found the special 2-stroke oil (called 2-cycle oil, hopefully the same thing) and read the instructions for 1:50 oil/gas mix. i followed the instructions using about 2.5 ounces of oil per gallon and started hearing a 'ticking' sound when accelerating (like the sound a baseball card makes in bicycle spokes).

i was reading about 2-stroke engines online where it recommended 4 ounces per gallon so i went home and added another ounce to the remaining half gallon i had, poured it in the gas tank and the 'ticking' was greatly reduced.

my questions are this, what ratios r other people using on their mopeds? would anything negative happen if i was to use a richer mix, like 6 or 8 ounces per gallon?

thanx in advance ; )


Re: petrol mixing ratios

50:1 is right....I used 43:1 in my mopeds, which is 3 ounces per gallon. Have you figured out where the ticking noise is comming from? Could be something that is loose. If it's in the cylinder area, could be piston slap.

Re: petrol mixing ratios

sounded more like the exhaust. i'm not real familiar with engines yet, but the sound definately was coming from behind me near the rear wheel where the exhaust pipe opening was.

since switching to the richer mix it hasn't been loud enough to notice anymore : )

Re: petrol mixing ratios

best thing is to do a plug chop. run your moped at full throttle for a few minutes, then kill the engine. take out the spark plug and look at it. it should be a nice golden brown (or tan at least). if it's gunky, you have too much oil and will eventually foul out your spark plug.

too much oil will also cause carbon build-up in the exhaust port and on the piston head. too little oil, on the other hand, can cause your engin to seize.

i use a bit more than 2.5 oz to the gallon, closer to 3oz. most people i know use about 2.8-3.0oz. 4 oz however is too much, i think.

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