This is a new and exciting development out of the blue. I'll list the things I have checked or replaced while diagnosing this! It was one day running fine, and the next it is popping and sputtering. Starts and idles great. No jetting changes were made because it was running acceptably.
It is strictly RPM related and not effected by throttle position. After stian's recent saga the first thing I went through was the silencer. It is a TurbineCore 2. Fully disassembled, blew all kinds of trash out of it with a pressure washer. Let dry, new packing.
Ignition:
New plug
KTM and GasGas CDI tried
Stator (OEM) with exciter coil
Metered exciter, pickup, ignition coil, plug cap, HT
Grounds, grounds, grounds!
Exhaust:
New silencer packing
New header/FMF Gnarly (it was on my list/needed one anyway)
Carb/Intake:
Drastic jetting changes with no effect - 165 and 180 main jets.
Thorough cleaning, disassembly and reassembly short of removing needle jet tower. (Peered through it, not quite scientific but it looks
)
Clean/oiled filter
Reeds
Float level checked, adjusted to close prematurely for curiosity's sake, no discernible change.
Adjusted to deliver excess fuel, bike would not start and dumped tons of fuel - invalid test
Engine:
Compression
Powervalve visibly checked - operational.
Inspected only through exhaust port but the piston still has factory machining marks. Looks like new with only a bit of color between the rings and top of piston looks a bit dark brown.
Drained crankcase, no residual oil (this is a first!)
This throws the biggest red flag????
I'm baffled and disgusted.
At this point the only bad idea is no idea. I'll try it if you name it.
It is strictly RPM related and not effected by throttle position. After stian's recent saga the first thing I went through was the silencer. It is a TurbineCore 2. Fully disassembled, blew all kinds of trash out of it with a pressure washer. Let dry, new packing.
Ignition:
New plug
KTM and GasGas CDI tried
Stator (OEM) with exciter coil
Metered exciter, pickup, ignition coil, plug cap, HT
Grounds, grounds, grounds!
Exhaust:
New silencer packing
New header/FMF Gnarly (it was on my list/needed one anyway)
Carb/Intake:
Drastic jetting changes with no effect - 165 and 180 main jets.
Thorough cleaning, disassembly and reassembly short of removing needle jet tower. (Peered through it, not quite scientific but it looks

Clean/oiled filter
Reeds
Float level checked, adjusted to close prematurely for curiosity's sake, no discernible change.
Adjusted to deliver excess fuel, bike would not start and dumped tons of fuel - invalid test
Engine:
Compression
Powervalve visibly checked - operational.
Inspected only through exhaust port but the piston still has factory machining marks. Looks like new with only a bit of color between the rings and top of piston looks a bit dark brown.
Drained crankcase, no residual oil (this is a first!)

I'm baffled and disgusted.

At this point the only bad idea is no idea. I'll try it if you name it.
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