NX650 power issue

I have a 1988 NX650 that has around 22,000 miles. I have installed a hotcam and completed Dave's mods. The valves have been properly adjusted along with all the fluids being changed. It still has the stock gearing of 15/45. It also has the stock dual exhaust and the snorkle is still installed on the airbox. I am running the stock paper airfilter. My problem is the the bike is rather unresponsive until it revs past 4K. Once it reaches those rpm it pulls very strong up to and past the redline. I was wonder what I should do to regain some of my lower end short of replacing the cam with the stock one? When riding some of the dual sport roads I travel I am constantly shifting to keep the bike in the power band. if it drops down below 4k it just doesn't have the guts to pull the bike in deep sand/gravel. Any suggestions?



it would help if you told us exactly what mods you made. did you rejet, if so to what size jets? below 4000rpm's, what exactly is it doing? you really need to get a foam filter and remove the snorkel.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By XR-CJ
      I have this issue several times and cannot seem to figure it out. The four clutch spring bolts are the weakest bolts I have ever come across. I am not sure what the torque specs are, have the shop manual, have searched online and I can only guess it's around 4 ft/lbs. I have been told 8 and they seem to break every time around 7.
      What is the proper torque for these bolts?
      Should I find stronger bolts? I would still stick to the proper torque, but feel as if these things are butter.
    • By XR-CJ
      Prior to reassembling the case, I tested the shifting and it seems the center fork attached to the shaft seems to stick at the steepest section of the drum. I have cleaned and tested all forks and surfaces for smooth movement, tried it with silicone and oil. With very little help, it seems to shift ok, but without the help, it binds.
      Can I assume that once it is together the oil lines are attached and oil is added to the case, the binding will stop? I have tested every scenario short of assembling the entire motor.
      Should I be able to successfully test the shifting with the case apart?
    • By Charles Mrizek
      contact me if you're interested.
    • By Charles Mrizek
      This replaces the tube that connects the two carbs on a 1987 Honda XR600R (it may fit other years). 
      Made in the USA. 
      Constructed of TPU  (solvent safe plastic.)
       Its durable stiff abrasion resistant yet flexible enough you never have to worry about breaking it when you're taking apart your carbs. 
      Fits the o-ring perfectly and slips into the carb nice and tight.
      Matches the rear shock coil. 
      If you would like to buy one contact me via e-mail. They cost $20 Shipping is free (anywhere in the USA). $10 off for active duty or retired military.
      Make your subject: XR600r