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Old 01-17-2015, 08:47 PM
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Davezilla Davezilla is offline
Motorized Bicycle Elite Member
Join Date: Mar 2014
Location: San Antonio Texas
Posts: 2,710
Default Re: MB.COM average speed poll results

That engine got a LOT of port work and it's balanced dead smooth, you can ride it all day because there's zero vibration at the handlebars and seat. I've even milled both the top and bottom of the jug to true up the surfaces so I can run copper gaskets, but also to place the jug exactly where I wanted it in relation to the crank in order to get the best port timing possible.
It was actually a pleasant surprise when I took a gps along for the ride and saw the max speed reached... especially after I ordered and installed a stock NT carb because I wasn't liking the Speed carb, and the CNS I got worked great but I was tired of fixing air leaks every other ride...

I got plans for my next engine... pretty much the same type port work and balancing but I want to make one that's case inducted, reed vavled, and run a 20mm Tillotson carb. The engine could also run a lot more intake duration if a reed was added.

If I can get enough free time at the shop tho I may put the Tillotson on this engine but I'll need to make an adapter for it as well as custom linkage first.

The port duration on this engine is a bit more radical than I originally planned but I went with this jug anyway and I'm glad I did since it still accelerates very well, it just 4 strokes some on it's way up because I'm running it a little too rich, but I'll tune it better after it's broken in all the way.

I'm also thinking about going up to a 40 tooth sprocket since this engine is screaming just under 10,000 rpm at 42mph with the 44 tooth and I'd like to bring the rpm's down closer to the 6K mark at cruising speeds.
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