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Old 03-26-2013, 09:11 PM   #3
old school
CharlieT's Avatar
Joined: Jan 2006
Location: Kalamazoo
Oddometer: 1,706
You're going to get all kinds of answers, but few will be right for you and your bike if all you get is an I run X-oil at XX:1 ratio. there is no simple single answer.

Look at one factor, one of the most important, the engine rpm range in which will spend most of your riding time. THe reason for this is that the rpm determines the contact time the fuel/oil mixture will have with the moving parts it is trying to lubricate. In a simplified explanation, the lower the rpm, the less oil is required in the premix. The higher the average rpm range run, the shorter is the contact period for the oil to be deposited and the need for more oil to be present in the mix.

As an example. When I had a Beta Techno trials bike, I typically ran a premix ratio in the 80/100:1 range. Most of the time, it ran in a low rpm range. Now in our road race engines, we typically ran a premix in the 16/20:1 ratio as they typically ran a very high rpms.

So when you ask someone what ratio they run, you need to also ask what kind of bike, what type of riding, etc.
A good bike mechanic only needs two tools, WD40 and duct tape. If it doesn't move, but should, use the WD40. If it does move but shouldn't use the duct tape.
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