'72 Whisker Top End Trouble

[Rapini]

My Arctic Cat Whisker is running a little rough ... it pulsates ( with the throttle fully opened ) it revs up but won't sustain or go into second gear. It just starts to rev up to higher rpms for only half a second and then it returns to cruising along in 1st. I'm thinking it could be a top end problem ... incorrect spark (although it starts first pull... maybe a slight misfire ? / or I've heard if you don't use the exact oil for the 2 stroke ? / I'm rebuilding the carb right now...not sure if that 's the problem ?/Tranny ? ) any ideas ?

Please advise,

 

[minibike_king]

when you open it full throttle does it kinda cut out like its not getting enough fuel?

 

[jesse8931]

it sounds like a carb problem are you using 4 stroke oil to mix with the gas ?

 

[Rapini]

Yes - it kinda revs up for a split second or two ... and that just starts to thrust you forward on the bike and make me think hold on tight here we go but instead it just drops back and putts along in first. Indeed it does feel like its not getting enough gas... as for oil I'm using a two-stroke engine oil 25:1

let me know what you think... in the meantime I'm busy cutting my own gaskets for the carb rebuild

 

[jimh]

If your bike is a manual shift, there's a possibilty the shift cam or barrel is out of time. If someone has been in there and not paying much attention, they could have put it back together out of place. When you think you're in 1st gear you may actually be in a higher gear.

 

[jesse8931]

it sounds like you need to clean the carb very good then find out what the air to fuel jet needs to be set at