Popping like this DES NOT always mean that it is out of time.
Is this a 4-cycle engine on the blower?
If it is, then the most likley problem is a problem that they have had since this model has come out. The overhead valve system has melted and is not allowing the valves to open and close.
It this is the case, then it is not usually repairable and you should just get a new trimmer.
IF it is out of time, the problem is almost always that the flywheel key,(That is actually mad INTO the flywheel is broken and you will need to replace the flywheel.
OK, I have looked up the blower,
Here is some information on the blower.http://www.wisesales.com/shindaiwa-eb8520-blower.html#.UBxjdaBXm9U
As far as I can see, this is a 2-cycle engine so the valve issue would not have anything to do with it since it doesn't have valves.
The flywheel key issue is still valid and also the electronic ignition could have gone bad and cause the ignition to be out of time. This is because there is usually "Spark Advance circuit inside the Ignition coil and if it is not working correctly, it will be out of time. There is NO other timing to be done.
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the engine has valves and I would like to know how to time the valves with the piston, the timing belt has jumped and I need to find top dead center and and how to place the belt on the correct marks
If your unit has valves, then it is a 4-cycle engine. I am NOT a Shindawa dealer and have NOT sen one of their 4-cycle engines, so I will have to opt out and hopefully a different expert has worked on this particular unit. Just about anything else you would like to onow, I would be able to help you with.
Hello,have you checked the valve lash first ? Did you have it apart and the reason you want to time it?