Any Suggestions: 04" NSR50

I have been trying to tune my sons NSR50 but can't seem to find the sweet spot, it has very poor acceleration which causes him to keep the throttle at VERY high RPM's through turns, definitely doesn't help at the starting grid either.

His bike is fully stocked, no modifications at all. The current set up is, Main Jet:103 and Pilot:42. I did swap out the main jet from 105 to 103 due to the weather being warmer but haven't seen any difference. I adjusted the air screw which helped a bit but need a bit more speed from the start.

Any jetting suggestions would be great, thanks in advance

where are you located?

Been a while since having a NSR, let alone with the 2-stroke motor. But I can help get the stock baseline settings.

How does the plug look? Timing verified? Air filter clean? Carb cleaned (as in remove all brass, soak in Berrymans overnight and all passages blown through with compressed air)? Verify all jets are clean. How about the baffle in the pipe? Plugged up? Need a little more info if possible.

Manimal said:

where are you located?

Been a while since having a NSR, let alone with the 2-stroke motor. But I can help get the stock baseline settings.

Click to expand...

Sent you a DM

you should start with the baseline stock settings, stock jetting (pilot and main) and a/f screw setting, premix 32:1. Nsr's did not come with a air filter. I ran 91 octane, when I had mine. If you add a air filter, and or exhaust, jetting must be changed. As stated above, check the color of your plug, and jet accordingly.

OTOH, you may need to re-jet, depending on your atmospheric conditions; dryer or wetter, than CA.
Although, regardless of the temps or wet conditions, I had never had to change any of my settings. In other words, my NSR performed well (maybe not optimally) with the same base settings, regardless.