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Old 06-17-2009, 10:12 AM
Forbisher Forbisher is offline
Join Date: Dec 2008
Location: Orange County, CA.
Posts: 119
Default Re: Will an 80cc motor handle my weight?

Originally Posted by lowrider View Post
Or is it an 80 cc motor that we are forced to call 66 here in America due to our forms of measurement ??
Huh??? who are you kidding? Is that the new math they are teaching in schools these days?
Where there are no wrong answers?
It is very simple math......

However, the bore and stroke of an 80cc being 47x38mm only equals 66cc.

To figure displacement for this example: 47mm bore x 38mm stroke; we use a standard formula to figure an engine’s cc displacement; ( multiply 3.142 x radius of bore mm squared x stroke length mm divided by 1000. )

Bore diameter divided by 2 = 23.5 mm radius

To square radius multiply 23.5mm x 23.5mm = 552.25 radius mm squared

552.25mm x 3.142 = 1735.17mm

1735.17mm x 38mm = 65936 cubic milliliters;

To get cubic centimeter divide 65936 by 1000 = 65.936cc or round off to 66cc.

As a result we see there is no such thing as a 80cc:

Last edited by Forbisher; 06-17-2009 at 10:18 AM.
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