Maintenance & Technical > KX500 Aluminum Frame Conversion (AFC)

2009 KX540

<< < (2/2)

umberto:
88 mm x 86 mm gets you a 525.  I went the same route, and love the 525 in my 03 KX250 conversion.  It sound counter intuitive, but everything I've read says you will need to run your carb leaner for the larger bore size.  I had to really go down in size on the needle (5x to 3x) and lean out my power jet in my Lectron to get it jetted correctly.  Now that it is lean enough, the bike is a blast to ride.

sandblaster:
Bigger bore, leaner jets.
Your sucking a greater volume of air through the same size opening in your carb, what happens? Greater air velocity.
With greater air velocity you will suck more fuel out of the carb, more then you need for the larger bore, requiring smaller jets.

sandblaster:

--- Quote from: supertuner on June 25, 2016, 03:28:47 PM ---1. Was the ported piston actually found to be effective? {port size and position that is best?}
2. Are C2 or C3 bearings preferred? {keep in mind I live in Minnesota and have never been to the desert}
3. Recommendations for crank assembly and balance?
4. Fill decompression reliefs in transfer ports or leave them before cylinder is plated? Head will have de-comp valve and possibly re-chambered but must be able to use 91 octane fuel.

--- End quote ---

Missed this one.
1. The koolaid man says about 1 hp gain at mid to high rpm.
2. There has been some debate about this. We use OEM and hide our head in the sand.
3. Too late.
4. I wouldn't worry about it at this point, I'm sure your 88mm bore will be plenty.

On your VF2
If your running in the woods, use the low tension settings.
ALSO, REMOVE EVERY BOLT ONE AT A TIME AND LOCTITE THEM ALL.... Or bad things can happen.

Navigation

[0] Message Index

[*] Previous page