Chain jumping or CVT issue?

[3boysandacart]

I posted this at the bottom of another post on carb issues but thought everyone would miss it, so I wanted to repost with a better title.

Just bought a Crossfire 150R at X-mas time and it feels like the chain is jumping a tooth under load. Almost like you are running over a small log every 5-10 seconds. I've check the tension in the chain and its good. Chain looks good, and sprocket doesn't look very worn.

Is this a CVT issue or maybe a sprokect alignement issue?

Thanks!

[SLESTAK75]

Does the chain have any missing or mis shaped rollers. I don't know if yours is brand new but the chain that was on mine was the very definition of POS. without even 50 miles on it I have had to replace it. Every ride ( short ride 1 mile ) the chain would stretch to point of skipping on the sprocket. Then rollers started coming out. I went to mfg supply and got a new one for 20 cents a link and no problems since. If tension is good and all rollers are good then check to make sure its the right type of chain ie not a 530 chain on a 428 spocket.

[Miamieddie]

Yup and check ur belt may be slipping...Eddie.

[xlint89]

Or you may have a broken tooth on your internal gearing. How about replacing your gear lube and inspecting it for signs of metal?

[3boysandacart]

Definitely given me some ideas on where to start. Thanks for all the input. Be back with answers soon.

[x-bird]

before opening up the cvt, look at the sprockets for correct alignment and also at the side of the teeth for indication of the chain running off center and climbing the teeth then dropping back. If that's the case, you'll see a gouge pattern on one side of the sprocket. could be a bent sprocket or gouged side plates on the chain links causing them to bind and skip. how much slack is in the chain?

[3boysandacart]

thanks, I think its a bent sprocket. There is metal debris on the left side of the chain that is either from the sprocket or the chain, but its misaligned. I'm going to take it apart tonight and know for sure.

thanks for the good advice

[bear]

Good luck, hope thats it!

[ckau]

Chances are chain skip is the problem. it doesn't take much wear on the axle sprocket to give skip. The belt or clutch in the cvt won't slip and grab, they just slip continualy until the load is removed. if the axle sprocket teeth seem pointed at all it's worn. If the buggy is a few years old then metal fatigue in the swing arm motor mounts, particularly in the rear mount can cause flex which gives enough slack to skip in a high load situation. The cheap factory chains will stretch. Though not visualy apparent, may seem fine but sections of the links stretch enough so the rollors won't seat into the sprockets correctly. Check for frame flex by placing the buggy up against a post or the side of a building then blimp the throttle enough to engage the clutch if you got swing arm flex the chain will go slack on the bottom. I've seen tons of worn out but never a bent sprocket, their pretty tough but anything is possible

[3boysandacart]

Thanks everyone for the detailed advice. I'll let you know what I find today.

[SYCARMS]

If it has the internal reverse it could be the output shaft.