KX500 engine rebuild

[2T Institute]

Have you checked the piston to bore clearence ?

[Recovered]

i could land a 747 in that end-gap.

[Marco810]

Have you checked the piston to bore clearence ?

Only have a caliper and odered a bore gauge off ebay, .01" was what i got

topend is way out of spec, bore looks to be good though

[xandyx]

with that gap you'll need another oversized piston, or that thing will slap like hell.

[91kx500]

porting, 250 ignition, 41mm pwk (pump gas), and what ever else i can think of

I recently built a CR500 engine specifically for MX so our two goals are miles apart, but some
of the mods I made would be beneficial for a dune bike.  For the top end, I had Eric Gorr do the
port and head work.  He recommended a Wiseco piston because it is more durable than the
cast OE.  I sent that piston and crank assembly to Crank Works for balancing at 6-8000 rpm
which is the meat of the powerband for a 500.  I also had all of the rotational internals REMed.
This process greatly reduces friction and heat and improves clutch action and shifting.  I also
installed a VForce 3 reed and a 2000 CR250 ignition with a Vortex IC.  IMO, all of these changes
would also be beneficial to a big power, top end engine. 

Here's a couple of pictures of my engine.  I look forward to following your build and to see what
you ultimately come up with.

With the lighter weight that monster is going to hit like a beast

Actually, the bulk of the weight (crankshaft), is still there.  The smaller rotor helps with the gyro
effect and makes the bike feel lighter and more manageable in the air and in corners.  The biggest
gain is going from an analog to a digital ignition and the ability to program the mapping.  You can
really increase the hit (if you're a sadist), or virtually eliminate it.

dogger

I see you have the Delta 3 reed valve system. Did that come with a boot that goes to your carb or do you have to use the stock boot?