Air Filter Arrangements 1985 XL 600 RF/650cc big bore

Has anybody any experience of doing this? - I have a low mileage 1985 XL 600 RF (dual carb) that I am restoring and rebuilding as a supermoto and the air box is such a pain to get back into the frame (which I have powder coated) that I thought I'd junk it and get K&N conical air filters to fit on each of the two intakes as I want to improve air-intake anyway.

I am also doing the following modifications:

- replacing the exhaust system with high flow stainless steel headers and a FMF PowerCore4 muffler

- Hotcam installed

- considering fitting a HRC 650cc cylinder for an XR 600 with an appropriate big bore kit if possible

I realise that jetting will need to be changed, but can I safely junk the air box and go to conical K&N airfilters?

Has anybody have any experience of taking a XL 600 RF out to 650cc??

Many thanks!


Wow, I know this post is over 5 years old and am surprised nobody ever replied to it. How did all the performance enhancements you were considering work out?

I have an 83 XL600 and opened up the airbox and plan on getting a FMF Powercore 4. Just curious. /Brian

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