QuestionThe engine fires only when I spray starting fluid in the carb intake. It does not start. It also backfires, gets tight when you pull the cord, even pulling the cord out of your hand with a slight reverse pull. I pump the side cold start on the carb and it does the same thing. I installed a new spark plug. With the plug out I can feel compression and suction for exhaust. Does the problem seem carb/gas related or ignition? I did ground out the spark plug and saw it spark when I pulled the cord.
AnswerEither the blade bolt is loose, the blade adapter key is sheared and or the flywheel key is sheared.
Or...I almost forgot, if there is oil in the cylinder it will cause the kick-back when you pull the string. All of the above will also cause the kick-back.
Since you mentioned the back fire, the most likely culprit is a sheared flywheel key. However, I would also check the blade bolt and blade adapter because either of these can cause the flywheel key to shrear.
You will have to remove the starter nut, washer and starter cup to inspect the flywheel key.
Do drain oil from the cylinder, simply remove the spark plug and pull the string. This will force any excess oil out of the cylinder.
Let me know what you find.
Eric
