KDXRIDER.NET

quick background on bike, picked this up used, internals already modded.

93 kdx200. steel lined sleeve. what I would call mild porting. RB head and carb. lightened and ported piston. rad valve. FMF, 40:1 hp2, sea level, 50-75F

Everything is in great working order, no air leaks, crankseals good, blah blah blah.

been scratching my head on this really as bike runs frickin hard, but has a bit of spooge, a bit more than necessary. Maybe a bit of a weak spot right before powerband in 5th or 6th going uphill but it runs so good otherwise I'm kinda scared to touch it.

I would think a ported bike would use more fuel per revolution? why am I considering dropping pilot to 128? doesnt that seem a bit small?

Hopefully someone with more knowledge on porting than me comes along with an answer. If you're running a 130 main now and thinking of going to a 128 then something is off. Your main typically would be in the high 140's or low to mid 150's. All bikes are different but low 130's or high 120's seems like a red flag. Do a general google search of something like "changes in jetting with 2 stroke porting". The spooge could come from the pilot circuit, the needle, or the main so you could seize a bike with a lean main and rich needle with spooge running down the silencer. The weak spot could be a lean issue. What jets, needle, and clip position are you running? Have you done a compression check or leak down test? Checked the reeds? Clean and oiled air filter, fresh fuel and spark plug? If you know that all that is sound then the next step is to follow the jetting guide to a T. One change at a time, dial the pilot, then the needle, then the main.

In general, no. Porting a 2T involves IMPROVING the air flow through the motor by cleaning up the passages, smoothing transitions and adding volume. All of these increase the fuel charge moving through the engine and so would require larger jets, not smaller. Porting is also used to adjust the intake/exhaust timing so as to gain optimum performance. You said pilot was 128, but I assume you meant main, and that does seem awfully small even for an unmodified motor...maybe its a 158? Spooge is a byproduct of 2T motors, you can never get rid of it completely, but can minimize it to a large extent through proper jetting of a mechanically sound motor.

Guys, I think he hit 1 and 2 at the same, time. I think he meant 38 pilot.