I have a 2000 ds650 it has plenty of low end power but nothing up high have changed cdi jets had the motor gone through has to be something electrical i have worked on plenty but this has me stumped. any ideas will help some are saying ignition coils are bad but 75.00 a piece i need a second opinion please and thank you.

 

Just a thought, but tight valves could also cause that problem.

 

valves and timing checked out ok I was riding it flying around then it started acting funny there is tons of power down low pulls the wheels off the ground. but when they land it is all over. we started with an engine overhaul no help then we changed the cdi box,no change the dealer said the ignition coils work on low rpm but dont put the proper spark out when revved high. this doesnt sond right to me I will check the vales again though thanks

 

restricted air filter?
As mentioned earlier... tight Valves
slightly plugged petcock?
Choke on slightly?

 

Wow. I didn't realize that the engine overhaul was done to try to correct this problem.
(I assume that you tried new plugs.)
What happens when you rev it up in neutral?

 

I had a similar problem. Mine turned out to be way to rich on the main jet. It would snap and pop on the top and not pull past 6500rpm. My experience with coils are they either work or they dont. Check you float level and clean the tank filters they may be plugged and its not getting enough fuel. just my .02

 

when i rev in neutral it wont reach the rev limiter the rev limiter is a big gun brand. all electronic is new except for the trigger coil and the ignition coils.

 

I think Scatterbrain is right. Sounds like the carb main jet rich or lean. Or fuel supply.

 

I figured this problem out it was the diafragm on top of the carburetor. it had a hole in it by the choke side flies like it used to thanks for the suggestions

 

my buddies predator had this same problem, it was like riding a honda fourtrax 300. it was soooooooooooo slow, couldnt even spin the tires on gravel and it ended up being the diaphram was collapsing, he was running my ds650 carb.