I have exhausted all channels on fixing my sons beloved KMX 50. We live on small farm with level grass pasture to ride on. Purchased last xmas and all was fine until March when the chain started rattling so I tighten it. Since then I have been thorough 5 carb joints in less than 30 mins of ride time combined. The carb joint keeps breaking at the base of the head. He is riding on level grass when it breaks. I’ve checked all nuts and none appear to be loose. Don’t want to sell but can’t identity the cause! Pls help if you can.

 

Might help if you show a pic. The part that is cracking, is it rubber, plastic, metal or aluminum?

 

It's the metal intake between the top of the head to the carb. See pic if I can figure out how to post.

http://forums.atvconnection.com/incl...lsize.cfm?ID=1pic

 

I have seen this in a 90cc bike. Look at the throttle cables, and make sure all their anchors are inplace. They can put torque on the carb that causes a side to side wiggle that stresses the aluminum of the intake.

 

I'd try to reinforce it with some epoxy while your at it, to hold it in place. Just go all the way around both sections. Supposed to dry harder than steel. Worked on my cracking aluminum exhaust problem anyway.