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Post by millsc on Dec 4, 2013 14:51:37 GMT -5
15lbs I tighten them as tight as I can get them with one hand always does the trick.
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Post by onewheeldrive on Dec 4, 2013 19:37:23 GMT -5
If you can afford it, you may consider upgrading the crank. I have considered it greatly recently. My first crank failed at about 15,000 miles with a stock bore. The other four between 8-10,000 miles, and those include 63 and 72cc big bores. Maybe I'm doing something wrong, besides running it super hard at 100+ miles a week, maybe not. It's really annoying.
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Post by ramblinman on Dec 5, 2013 7:00:41 GMT -5
If you can afford it, you may consider upgrading the crank. I have considered it greatly recently. My first crank failed at about 15,000 miles with a stock bore. The other four between 8-10,000 miles, and those include 63 and 72cc big bores. Maybe I'm doing something wrong, besides running it super hard at 100+ miles a week, maybe not. It's really annoying. wow, 5 failed crankshafts? splitting the case is something i'd rather not try. i've been thinking about getting a 150cc but if i can get 50+mph out of my scoot then i may wait awhile longer. my scoot has nearly 14,000km. i don't know exactly since the speedometer broke and i rode it for about 3 weeks before fixing. hopefully this old engine can handle the extra hp otherwise i will be stuck riding my bicycle to work until i get a new scoot. edit: just remembered; i've read over tightening the variator nut can damage the crankshaft bearings. maybe over torquing that nut with an impact is more to blame than a bbk. i don't know but it's something to consider. someone correct me if i'm wrong. |
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Sophomore Rider
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Post by buford1488 on Dec 5, 2013 8:43:33 GMT -5
if your looking for 55+ you might want to talk to millsc some more..he almost hit 60 with his build.......buford..
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Post by onewheeldrive on Dec 5, 2013 17:19:01 GMT -5
wow, 5 failed crankshafts? splitting the case is something i'd rather not try. i've been thinking about getting a 150cc but if i can get 50+mph out of my scoot then i may wait awhile longer. my scoot has nearly 14,000km. i don't know exactly since the speedometer broke and i rode it for about 3 weeks before fixing. hopefully this old engine can handle the extra hp otherwise i will be stuck riding my bicycle to work until i get a new scoot. edit: just remembered; i've read over tightening the variator nut can damage the crankshaft bearings. maybe over torquing that nut with an impact is more to blame than a bbk. i don't know but it's something to consider. someone correct me if i'm wrong. Yeah a couple were from rebuilds, and a couple were from new engines. The first 2 were stock 50cc and the main bearings went out--- one was the oil pump side and the other was the variator side. With the bigger bores, the rod bearings went out. I guess it could be possible about over-torquing the variator nut. All I know is that the nut stays on after a few whacks--- I use an emergency impact that I got from Walmart, so I really have no idea how much torque is being applied(compared to Harbor Freight impact, may not be much difference). I actually thought that could be a possibility--- too much torque, and that's why I've actually considered buying a holding tool for the variator, to at least get it closer to the proper spec. What about shocks/front forks? Maybe I have too much jarring and excessive stress on the engine--- because my frame and shock has been the same since day one, minus the mount bushings I had to replace(not ON the motor--- the mount from the frame...) |
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Post by JerryScript on Dec 6, 2013 0:17:06 GMT -5
You BBK will give you plenty of power, but not necessarily get you over 50mph by itself. Most likely, you will need to change your weights to 1 or 2 grams heavier in order to achieve the top speed you want. A performance variator that is a larger diameter than your stock one will also help with a few extra MPH. In the end, you may have to change your gear ratio in order to reach those speeds without topping your engine's redline.
If you don't tune the weights in your variator, you may still achieve 50mph+, but your RPMs may be too high, which definitely could lead to crankshaft or other failures.
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