'09 Trike drops cylinder at 3K while tuning

[VDeuce]

Posting this on behalf of a friend that is a shop owner, pro engine builder and pro tuner with a dyno. We are baffled as to what is happening.

2009 Trike, new 117 kit, Redshift 575 cam, HPI tb, Freedom exhaust duals with Reinhart mufflers. Customer bike.

Tuning with PV, widebands.

Bike drops front cylinder when rev'd with no load  (or loaded) at 3K RPM. Data logs show spark and injector pulses at these conditions, but cylinder drops out causing a huge hole at that RPM. Really messes with the tuning process.

Have tried disconnecting MAP sensor and then it can hit 3K without dropping. Suspect MAP sensor?, new one on order. Have tried 4 different maps from dynojet; same. Tuner has calibrator mode and IVO/IVC have been set.

Wondering about ECM, intermittent connection somewhere, exhaust length. May try different pipe if MAP sensor and temp sensor don't work. MAP load has been played with. Reversion tables have been played with, no diff.

Any idea what the heck is going on?

[rbabos]

Posting this on behalf of a friend that is a shop owner, pro engine builder and pro tuner with a dyno. We are baffled as to what is happening.

2009 Trike, new 117 kit, Redshift 575 cam, HPI tb, Freedom exhaust duals with Reinhart mufflers. Customer bike.

Tuning with PV, widebands.

Bike drops front cylinder when rev'd with no load  (or loaded) at 3K RPM. Data logs show spark and injector pulses at these conditions, but cylinder drops out causing a huge hole at that RPM. Really messes with the tuning process.

Have tried disconnecting MAP sensor and then it can hit 3K without dropping. Suspect MAP sensor?, new one on order. Have tried 4 different maps from dynojet; same. Tuner has calibrator mode and IVO/IVC have been set.

Wondering about ECM, intermittent connection somewhere, exhaust length. May try different pipe if MAP sensor and temp sensor don't work. MAP load has been played with. Reversion tables have been played with, no diff.

Any idea what the heck is going on?

If the spark and injectors are happening in the data at that rpm and moment, I'd be looking at possibly a sticking valve. Although if compression is lost by that, spark should not occur on that cyl and possibly a code thrown.
Ron