80cc 2 stroke Bike wont start

GoldenMotor.com

Joey Weidner

New Member
Mar 7, 2020
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I recently bought a 80cc 2 stroke bike off of offer up and it was listed as not running so first thing I did was replace the carb and clean the gas tank after doing that i tried to start it and my throttle cable broke so i replace my throttle and kill switch and then i tried to start the bike again but still no luck so i checked for spark and I did have any so I replaced the Magneto, Cdi box, and the spark plug Now i have spark and my gas runs well but my bike still wont run I watched every video on YouTube and tried many things but i just cant get it to start
 

allen standley

Well-Known Member
Oct 22, 2011
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Bangor, Maine
Welcome Joey,
So you have fuel, You have spark. One more thing needed - does the engine have good compression? Pull the 5 bolt cover on the right side. Do you see fuel pooled in the bottom of cover? There is an engine seal behind the small gear. If no seepage, Pull the Mag cover opposite side see any fuel or seepage behind the spinning magnet? There is an engine seal there also. Next - Leave the covers off - Pull the plug, release the clutch and wheel the bike around with your thumb over the plug hole. You should feel a suck and a blow out the plug hole. If you have, or can get a compression gauge hooked up you will want a minimum of 90 lbs. While wheeling the bike around with clutch released, check to see if all the gears on both sides are turning, there are 4 shaft keys in the motor if the key under the spinning magnet is sheared this too will cause a no start condition. Watch this animation about your motor to give you some understanding.
Worst case scenario, You may need a top end rebuild. How are your mechanical abilities?
https://www.amazon.com/JRL-Cylinder...words=Gas+bike+cylinder&qid=1583928211&sr=8-4
 
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Joey Weidner

New Member
Mar 7, 2020
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Im sure I could do it but I just dont know if its worth my time. I feel like it would be better to sell it get $100 for it and eventually buy a brand new engine and bike