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Post by sirtokesalot on Jan 25, 2017 15:03:01 GMT -5
ive been working on a few scooters recently with the motivation that if i get one to run for him i can use the remaining parts to build one for me. the issue im having is that the scooter wont run. i have changed the gas - cleaned the new carb - found missing intake gasket o ring and replaced it - checked valve clearance adjusted valves - retimed the engine it was off one tooth - disabled vacuum fuel shut off - tore the engine apart found one of the rings was stuck replaced cylender and piston with low mile cylinder and piston from my old scooter days i had as spare parts currently scooter still wont run. it has spark compression air and fuel are getting to the cylinder when i crank it the engine sputters and if i hold wide open throttle the rpm raised up as it sputters faster trying to run but just wont kick over and actually run. am i missing something?
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Post by tortoise on Jan 25, 2017 17:25:16 GMT -5
Verify flywheel/crankshaft woodruff key has not sheared . . which alters trigger-coil timing. Insert a probe into the sparkplug hole and turn flywheel to position piston at top-dead-center . . then observe if flywheel T-mark is aligned with case indicator.
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Post by sirtokesalot on Jan 25, 2017 19:24:49 GMT -5
Verify flywheel/crankshaft woodruff key has not sheared . . which alters trigger-coil timing. Insert a probe into the sparkplug hole and turn flywheel to position piston at top-dead-center . . then observe if flywheel T-mark is aligned with case indicator. i had the head off today and the piston was all the way up with it aligned at the t mark. |
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Post by tortoise on Jan 25, 2017 19:53:18 GMT -5
Any chance a Kymco flywheel was installed on a non-Kymco 139QMB engine?
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Post by sirtokesalot on Jan 25, 2017 22:05:09 GMT -5
im not sure someone els was working on them before me and had done so very poorly i have been told all of the 4 engines there have been apart and back together a few times. is there a way i can tell from looking at it? as it is right now i have ordered 2 80cc kits because he wants his to go faster and the one im going to be able to keep will need one as well. i also bought a new carb because all the carbs he has in the garage are crap non tune-able carbs the only good carb is the one on the bike im trying to get running now i was told it is new but cleaned it anyways. im supposed to get these parts on monday so ill probably be going back to work on them again next Wednesday they are not at my house.
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Post by tortoise on Jan 25, 2017 22:19:17 GMT -5
Verify flywheel F-mark alignment positions the reluctor under the trigger coil.  |
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Post by sirtokesalot on Jan 29, 2017 15:24:36 GMT -5
the f mark was lined up to the reluctor but i did figure out why it wouldn't run when i was checking the marks i lined it up to the T mark and the piston was still half way down the cylinder even on the f mark it was still not at the top. i just built one of the other engines he had in the garage swapped it over and it fired right up. i began building the next one that is going ot be mine got it all together and had the same issue where it dident want to run when kick starting it i jump started it from my car it started and ran but the wheel was spinning and wouldent rev right took side cover off after he told me there was a new belt on the one i was building for me they never reset the variator so its jammed in top gear have to go back again now with cordless impact for that but im now confident its gonna run as well.
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Post by sirtokesalot on Jan 30, 2017 6:38:15 GMT -5
went back again last night and fixed the jammed variator the second one started right up no issues after that as well.
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