Engine Knockin what to do.

[bgoodwin73]

Hey everyone I have a Dax 80 I bought about 2-3 months ago I finally got it on a bike and after maybe 3-4 hours of riding im getting a really bad knock in the engine. I run it 20:1 and have been pretty easy on the throttle. I have sent an email to Dax so a refund might be there but I would like to try to figure out how to fix it or what is wrong with it myself. Thanks and any ideas on what might be going on.

Ps I pulled the head and jug and there wasn't any scoring or marks on the piston or cylinder wall at all. Im kinda stumped.

 

[Mountainman]

??

did you check for up and down play on the rod bushing ??

does it sound like a rod wanting to bang itself out of there ??

kind of like a little hammer taping THING ??

ride that thing

 

[bgoodwin73]

I didn't check for the up and down play of the piston. I will check that tommorow. Should it be a snug fit or do these have some slack. Also I think it might have that tapping sound like a hammer but I dont know. thank for the reply I really want to be able to fix this myself.

 

[arceeguy]

The design of the clutch causes these engines to make a metallic rattling noise, especially with the clutch disengaged. There should be very little play in the piston pin and lower end of the rod. If these parts look good, then I think that the little carbide balls in the clutch are "wearing in" and causing your noise. You can try and force some grease into the bearing area, but be careful not to contaminate the clutch pads.