Author Topic: KX60 Tuning for Racing - Engine and Suspension  (Read 6644 times)

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Offline cbrfrenzie

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KX60 Tuning for Racing - Engine and Suspension
« on: September 24, 2012, 02:36:35 PM »
Hello all,

I've been reading along for a year or so and felt like I should start something new here.  I know this is a KX5 dedicated site, but since I own a 1997 KX60 for my son, I've been tinkering with that lately and would like to share my experiences.

I want to start my kid racing next year in the 65 class here locally, so I started getting the bike ready.  I tore the front end down and rebuilt the front shocks, with stock springs and 5w fork oil (all air bleed at max fork extension).  The bike now handles like a DREAM compared to how it did before.  The oil in there previous was really grey and mucky... I'm sure it wasn't ideal (keep in mind this is for a 55lb 8 year old).  He LOVES the way it handles now, and is going like crazy over the jumps now!!!  While I had the front end apart, I tore out the factory ball bearings and retainers in the stem tube and replaced them with a press-in set of tapered roller bearings from All Balls Racing.  I believe this too helped firm up the once SCARY front end of this bike.

I have done many different things to the engine over the past year trying to find the right combo for power output, and believe I am closer then ever.  I did the Eric Gorr groove in the jug on the intake side, basically creating side boost ports.  I replaced the filter with both Twin Air and UNI units, and found both to perform about the same.  I stuck with the UNI as it the was the second one I tested.  This along with a set of dual stage reeds, new intake rubber and clamps, and a cleaned carb made it SNAP down low.  I'm also running 93 Oct with Castor 927 @ 32:1, same as I run in my KX5.

I played with the factory pipe and silencer, packing it different ways and trimming down the silencer.  The stock pipe is a good mid-range pipe, making the power band seem really peaky.  I put a Pro Circuit Works pipe and Pro Circuit Factory 304 SS silencer on it and man that is what I was looking for!!!!  This thing wheelies in 6th gear, with ME riding it!!!! (175lbs)

Finally, I topped everything off by jetting the carb appropriately.  I got some main jets, and under and over sized Banshee pilot jets (27.5 and 32.5 respectively) and started playing.  Dropping the main to a 180 (from 200), dropping the pilot to a 27.5 (from a 30) and putting the needle on clip #3 from the bottom is where this thing sings!  We live at ~4200 feet for reference.

I've got a Wiseco +2mm piston for it too, along with the Cometic High Compression top end gasket kit I may install down the road.  I want him to start racing and see where he stands against the stock KX/KTM 65's that are running the area.

I also put new EBC brake shoes in, and cleaned up the hubs really good and replaced the wheel bearings with the All Balls set.  New chain and aluminum sprockets, running -1 in the front and stock on the rear.  I also installed a new EBC Kevlar clutch set with new steels, and new stock springs (the EBC springs are too stiff for my son to pull in the clutch, perhaps next year lol).

Does anyone have any input on this bike and what works good for racing?
« Last Edit: September 25, 2012, 01:55:17 AM by cbrfrenzie »