We have a 97 prarie 400.I have replaced the spark plug,cleaned the air filter,drained the sediment bowl on the carb.
But still it will only go 50kms.per hour tops,then it just powers out! Can anyone tell me what could be wrong?
Thanks,DANDELION.

PS.I solved the problem,i just blew a little air into the sediment drain on the bottom of the carb[don't ask me what it did but it runs like a top]
Thanks TREE FARMER for your reply

 

Not much to go on, but:

Assuming your fuel is clean and dry (no condensation in the bottom of your float bowl; add some "dri-gas" if unsure), is your slide and needle rising when you open the throttle? A bad vacuum seal in the top of the carb (slide diaphragm leak) can cause the condition you describe.

With a free flow of good fuel, spark and compression, you'd expect the thing to run better than you describe. Good luck; let us know what you find out.

Tree Farmer