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Post by blazejin on Apr 16, 2019 3:29:36 GMT -5
In the cold morn. when starting, I use the electric start. it turns over fine for the first hit. Then its like the compression builds up. Then I kick one time it stars right up. When its hot I have to WOT with electric start to crank. valve lash is 004 both sides, and I have went up and down on the lash a little with no change. It is a taotao 139qmb with stock carb. I have 5000 miles on the scooter, I have built the engine 2 other times the same with no problems at all. anyone know what is going on with this thing ??
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Post by chewbaca on Apr 16, 2019 13:09:56 GMT -5
sounds like you could use a valve lap and a cylinder hone
or possibly a week starter is the problem
If it was me I would get a new head and cylinder to swap in
so you can take your time to rebuild the old ones.
A head swap is so much easier to do without having to mess with the spring retainers and oil seals
the little fifty motor runs fast on the rpm per mph
makes the entire engine ware out faster
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New Rider
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Post by blazejin on Apr 16, 2019 17:48:50 GMT -5
Thanks for the reply chewbaca, I was leaning towards the head myself, I also have some sputter backfiring going on when I come off the WOT. I was thinking maybe a valve seating problem. Would you happen to know if its a plus to have the 82cc on the long case with the 12" wheels. I already have it built with new top end . I will prob. change my forks and swap engines this weekend to see if there is any kinds of differences between the short vs long case.
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Post by chewbaca on Apr 21, 2019 10:42:16 GMT -5
the long case comes with a different final drive gear and is intended for a taller wheel
if a ten inch wheel can fit the axle it would be a wheelie machine, especially with 82cc
the popping you hear when you drop the throttle is an exhaust leak letting O2 mix with the extra rich idle mix. Fixing the leak needs either a new gasket or finding and plugging a hole in the pipe.
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New Rider
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Posts: 37
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Joined: May 20, 2016 16:26:12 GMT -5
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Post by blazejin on Apr 21, 2019 13:18:55 GMT -5
OK thanks, I did have an exhaust leak, I fixed that and tuned in my air/mix closer and its ok for now. so far so good. I thought as much on the final gear for the wheels but I was going to go with the 12" wheels. don't need a wheelie monster, lol thanks man, have a bone  |
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