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Old 08-31-2010, 10:16 PM
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mapbike mapbike is offline
Motorized Bicycle Elite Member
Join Date: Mar 2010
Location: Central Texas
Posts: 5,379
Default New 2 smoke I built from bottom up is running strong so far

Well, for any who remember I had a major 66cc engine failure a few months ago on a bike I had put together, BGF sold me a new jug at a very nice price and Jim at Manic Mechanic made me a great deal on a new piston, pin, upper roller bearing & rings, I also bought an entire used lower engine case that still had a good crank & rod in it from StrontiumEthics I finally got it built last week and mounted it on the bike yesterday, I milled .012 off of the stock slant head and smoothed up the ports in the jug and the blocks transfer ports, so far I have put 26 miles on it in the last 2 days and that booger is running real nice, I have a 36T on the rear that I made up from from a crank sprocket that was on a little 16"kids bike and I built my chain tensioner roller from a skateboard wheel and it all works real nice, it runs real smooth up to 35mph before it starts the butt buzzing vibration at 37mph, but if it does like the engine on my mountain bike it will settle down after a couple hundred miles and get a lot better in that area, I still need to build an expansion chamber exhaust and I may tweak the carb. a bit depending on how it runs out but so far I am very happy to have this engine back together, I could have bought another engine for less than it cost me to completely rebuild this one but the one I have now is a much better than new out of the box engine plus I had the enjoyment of doing it, dont have any real good pics of it yet but here are a couple I took yesterday evening of the bike and the tensioner.

Attached Images
File Type: jpg Kar_Bike.jpg (123.9 KB, 51 views)
File Type: jpg Kar_Bike2.jpg (111.4 KB, 45 views)
File Type: jpg Kar_Bike_Tensioner.jpg (47.5 KB, 51 views)
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