Klx250s cam mod (marcelino mod)


Made the cam mod. I did just the intake side. The difference is noticable. Bike intake sound is different and it pulls really good. The mod is kinda tricky to make as you easily get confused during the change and loose your situational awareness. If you want to do the mod, just search for marcelino cam mod. Some people do it for the exhaust side. Some for both sides. The problem with the exhaust side is the automatic decompressor automatic that needs to be reset. So doing the intak only is simpler and seems to give nice power even without the exhaust side.



2 responses to “Klx250s cam mod (marcelino mod)

  1. Hi James,
    So, 3 years later, do you still have your KLX? If yes, can you make a feedback about the intake timing mod? I’ve seen your videos about the other mods but nothing about the “semi-Marcelino mod”. Did it impact your fuel consumption? Is reliability still good? Did you operate other mods due to this one (EFI remap… etc…)? Have you eventually dyno’d it? 😀
    Thanks. Regards from France.

    • Not anymore. I sold it year ago. I didn’t dynoed it and I think the top horsepower did not change. But I liked the engine more after that mod. It doesn’t stall that easy if you are driving offroad at very slow speed. And engine is pulling very good at middle range. Fuel consumption was the same. Something like 3l /100km.
      I did check the fuel mixture with lambda sensor and it was OK after the cam mod. So no need to change it.
      Reliability was same. No problems. But in 250cc bike the benefit is so small it’s maybe not worth the hassle and the risk to make a human error while doing it.

      Hope this helps.

      The clutch switch and intake tube mod are necessary and easy to do. And provide very good bang for the buck and with minimal hassle.


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