2006 Yamaha Raptor 350 Slapping/knocking upon trying to start

[Donaldhang92]

Hi, I am new to the forum I bought a 2006 raptor 350 I test drove it. It ran decent but thought it was just due to the cold, after I got at home I rode it around and it would just die out/ lose power upon letting off from heavy acceleration or down shifting, it will just lose power and die out, I took carburetor apart cleaned it pretty well, it ran a little better at first then 1 minute into test ride she died again. Now I’m back to my shop and try to start it again and I’m left with a crazy slapping clicking noise I’ve never heard before. Let me know if you have heard this or know of the answer to my problems thanks ! 

 

 

[Mech]

I don't know those things but if it's a two stroke I'd pull the exhaust off and have a look in through the exhaust port at the piston.. looking for scoring or signs of overheating seizing. That might be the cause of your noise.

I'd also undo the drain screw on the bottom of the carby and check the fuel flow is adequate. If there is plenty of fuel getting through and the piston looks ok, then I'd take the carb off again and strip it entirely and clean all it's jets and drillings, and check the manifold for splits if it's a rubber one, or missing gaskets or O rings if it's a metal manifold.