knocking noise from my engine when i shut the throttle

[wizbit]

hi im getting a knocking noise from my engine when i shut the throttle i have only just bought the bike and on my first run out for an mot this started also the bike does not seem very fast it wont even pull the front wheel up in first gear is this normal it starts first time every time anyone got any ideas what this could be or are they all like this any help would be good cheers phil

[Jonorow]

1st question, are you used to the sound of a two stroke? silly question but some people have got confused with the normal sound and a problem.
2nd, the crm is not like a cr and does not ordinerily lift the front wheel all the time.

Check the compression, and check the piston looking through the exhaust port for any wear or scoring of the piston, if the bike hasn't been used for a while the carb could be gummed up and the fuel might be a bit old.

If the piston has worn you will get a lot of piston slap (knocking) but this would be most of the time. Ultimately the best way to be sure is to lift the head/Barrell complete.

Someone else might help you more.
Jon