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Post by geoffh on Dec 31, 2017 10:08:57 GMT -5
Feel free to add your own method below.Intended as a guide only, pick your own ratio 32.1 is quoted as safe for normal road use.You can find ratio charts on Google Image.
Cheers geoff
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Post by geoffh on Dec 31, 2017 10:12:35 GMT -5
Yamaha jog 49cc. just better than stock revs around 6500 to 7000 for short runs. I.ll update later  I,m aiming for 40.1 so every litre of gas needs 25ml of oil adding,thats a 100ml in the jug  This my soda bottle used to transport the oil to the gas station the small amount in the bottom is always there  My soda bottle ready to go  At the gas station I just pour it in then add 4 litres of gas,easy no mess.I keep a bottle of oil under the seat for top ups and I,m never far from a gas pump so this works for me. |
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Post by jackrides on Dec 31, 2017 13:23:44 GMT -5
Just to be sure a slug of oil doesn't go straight to the carb, put some gas in the bottle and swirl it around then pour it in.
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Post by ThaiGyro on Jan 1, 2018 4:11:10 GMT -5
Nice thread topic.
For stock/OEM to mild street performance upgrades. Going to a ratio other than manufacturer settings is a waste of money and environmentally substandard. (If you see smoke beyond cold start and warm up, then you are tuned wrong)
My '84 Honda Gyro had a pump that delivered inconsistent oil. It was supposed to be 40:1. My first modification, on an old tired engine, was to dump-the-pump and go pre-mix. I now have better ignition, different carbs to use and a 10,000 rpm pipe, which is 16% more rpm gain.
I still mix at 40:1. No issues. The real positive was that it smokes less at cold startup and never has a startup issue. On electric start, it takes four or five crank rotations. On kick start, one or two. OEM settings are way to conservative.
Extra oil protection in my history, begins with a combination of rpm, ignition advance and compression. In the 10,000 rpm range, maxed ignition curve and everything tuned proper...I still run 40:1. When that same engine gets some compression boost and a tad more rpm...maybe 32:1, depending on real measurements...I went from 8.5:1 compression OEM/stock to 9.2:1, plus ignition timing advance and the rpm boost. It shits and gits! Near the edge of explosion? No way.
What that equaled in terms of performance? Mid range power and no soft seizes. (Mine were caused by the oil pump function lacking at +8400 rpm.) Top end speed improved over 12%. Fuel efficiency was not measured, but less can be more. Too much oil mix creates a situation that forces richer mixtures. You see white exhaust smoke because your engine will burn the combustion fuel before the protection fuel, but the spark has died. Even with pre-mix, your ignition spark fires lighter fuel first, actually forcing the 2T oil to the walls. Good!
Lubrication! The extra heat from the above friction, causes the super heated "protection" oil to burn, in varying degrees. Cold produces smoke. Properly warmed up produces power, but no smoke to be seen.
The 70's mentality for 2T street bikes: Most had oil pumps that were shit...but people would fill their petrol tanks and splash in a bit of "extra" protection, that was NEVER needed.
I know! Those dummies made me loads of cash fixing their engines. I raced for many years on others bad decisions.
Beyond that....race prep. A different thread, I think.
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