Yamaha yt175 running reverse

Yamaha yt175 is having some troubles.

I have just picked up a new three wheeler. And havent had it running yet!

When pull start it, it fires and snaps the cord out of your hands. Some times it brakes off, and when you pull the assembly apart it looks as if the engine had been running in reverse? Strange I know but does any one have an idea what might cause this to happen.
I have pulled it down and checked that it hasnt shared the flywheel key but all checked fine.

Any ideas would be great thanks

Nick

Is this a 2 stroke or 4 stroke?

If its a 4 stroke Check the valves to make sure they are closing and opening when they are suppose to be.If they arent then that could cause it to backfire.

If its a 2 stroke check the reed pedals to make sure they arent cracked or loose on the cage.

yip its 2 stroke. I will have a look at that today cheers!

the ried valves checked out fine! had a bit more of a play around with it last night and managed to get it running. Dont know what i did but it went well. But today it would just snach the cord back and back fire. Coudnt get it going at all!