900 hi-comp pistons, and now it won't run below 2500 RPM.

[Speeddog]

Is it the spark or the fuel that's quitting?

Dunno how much that helps, they're both controlled by the ECU.

Fresh out of ideas now. 

[Tenshikurai]

TPS voltage checks out fine.

Does anyone know of any incompatibilities between 2000 sensors and 2002 computers?

[Tenshikurai]

The only other thing I can think of doing, would be to swap all the 620 stuff back onto the bike and attempt to tune it for the extra displacement with the PCIII.  If I were to do so, does anyone have a ballpark as to how much extra to add via the fuel tables?  Specifically, are the values in the tables a percent of the duty cycle? or some arbitrary value it uses?

[greenmonster]

Around 25-30% more fuel above 10% throttle, not so much difference below 5% according to base maps I have.
Values usually milliseconds injectors are open.

[Tenshikurai]

Thanks, I'll give it a whirl for a baseline.  If it's enough to get it running I'll worry about dyno tuning.  If it's not the answer, I'll keep scratching my head.

[Tenshikurai]

Ok, so with the 620 ecu, gauges, etc. installed it definitely ran better below 2500 rpm.  It was obviously lean above 3000, so I added 30 to the PC3 tables.  At that point it would run down to about 1800 rpm.  I took the 2500 and below area of the table and removed 10 from the tables and it was enough to run down to approximately 1400-1500.  Adding or removing fuel below that point seems to make no difference

I'm hoping I've got it running well enough to get it onto a dyno and get some AFR's and find out exactly what's going on with it.

[Tenshikurai]

Just picked it up from the dyno, AFR's are a touch lean, but nothing weird.  Some misfires at low RPM, but the powerband is real smooth.  We only ran it up to 5k rpm, but made 61hp, and 90ft-lbs of torque.

I'm still getting a lot of oil in the horizontal cylinder, so that's coming back apart this weekend if I've got time.  Didn't find anything last time, but it still indicates a problem to me.

[OT]

Was the light flywheel on (and the bike running well) before you changed the pistons?

[biffborax]

Just picked it up from the dyno, AFR's are a touch lean, but nothing weird.  Some misfires at low RPM, but the powerband is real smooth.  We only ran it up to 5k rpm, but made 61hp, and 90ft-lbs of torque.

I'm still getting a lot of oil in the horizontal cylinder, so that's coming back apart this weekend if I've got time.  Didn't find anything last time, but it still indicates a problem to me.

90ft-lbs of torque with just hi-comp pistons(and a PCIII and dyno tune)?!  That's amazing! I am impressed! Good work.

[Tenshikurai]

It wasn't tuned yet, I was just getting air/fuel logs to try and diagnose the problem.