Another Wont start engine with a twist.

Discussion in '2-Stroke Engines' started by Sitherus, Oct 1, 2016.

  1. Sitherus

    Sitherus Member


    I picked up a motorized Stinger 66cc motorized bicycle on the side of the road i spoke to the owner to make sure he was throwing it away. It had so much dust on it. He said it had not run in 5 years. I took it home cleaned out the gas tank and carburetor, completely disassembled the carb and made sure the fload didnt have any holes. I took apart the engine cleaned it up cleaned the piston. I replaced all the gaskets. put in a new r4 12 spark plug (the same one i use on my other builds) Fixed the broken throttle. tightened the clutch. and tried over and over to start it. eventually flooding it. so i took the spark plug out let it sit for 24 hours then tried again. I took apart the magneto and performed a spark test (not in that order) I was getting blue spark when the piston was at its lowest. so i flipped the magnet so that its notch was at the 1 o clock position reassembled the magneto and magnet. i tested for spark again. there was none so i replaced the cdi with one i knew was working. and i got white spark. not blue not yellow. I tried again making sure the spark plug wasnt wet to start but to no avail. I then tested the magneto with my multi meter to get 350 ohms but my ohm meter could only read 200 or 2million. so i got something like .365 which i dont know what to do with. I spun the back wheel and tested the spark plug it got around 11 ac. I dont know what to do.

    My theory is im not getting enough spark. The engine sounds fine the piston is moving all the gears are meshing. The carb looked fine. the gas tank isnt leaking. im using one small bottle of 2 stroke oil for every 1 gallon. (I suck at ratios) I am afraid to use starter fluid at risk of using too much.

    Is this engine even worth fixing?

  2. Sitherus

    Sitherus Member

    im getting fuel to the carb and the engine starts with starter fluid but wont keep running. does this mean i need a new jet? or is it easier to just replace the whole carburetor.
  3. crassius

    crassius Well-Known Member

    these carbs are simple - check float level and clean the jets, be sure needle didn't drop into the bottom
  4. jaguar

    jaguar Well-Known Member

  5. try checking compression even if it feels right....check the piston rings and seals they can move or split or wear out due to sitting around with no lubrication. I reckon that is your problem.