RXP X modified RIVA stg 4

[ctd]

I'm trying to sort out a RIVA stage 4 modified water craft & I'm curious if anyone using HPT has figured this out. It was previously a RIVA supplied ECU & ran well, unfortunately an engine failure that I fault somewhat on the lack of KR detection using the aftermarket ECU.

The factory ECU is back in with the RIVA injectors & modified programing. Both rev limits are set to 9200rpm & the AFR is close.

Aprrox. 8600rpm I believe the soft rev limit is starting to interfere. What I see is timing retard with center cylinder & it becomes more aggressive the longer WOT throttle is held.....several degrees. Some retard is seen with the rear cylinder, only a couple of degrees. Something begins to hold the motor back @ this rpm & does not allow the motor to rev beyond.

The AFR @ that point also begins to richen, I'm not sure if that is the same soft rev strategy or not. It's inconsistent so I'm not sure if it is related or not.

I'm data logging with EFI analytics, so I'm limited to what I can see.

I've watched this thread & it seems a few have a handle on this platform. I need a reason to upgrade my HPT

[Tbranella]

are you using Riva map editor to adjust the tune now?

I'm basically Riva stage 4 (no cam) using HP Tuners to tune my setup.
not looking to rev to 9200 rpms though.. I'm happy with 86mph @ 8650rpm... my limiter is set to 8800

[ctd]

are you using Riva map editor to adjust the tune now?

I'm basically Riva stage 4 (no cam) using HP Tuners to tune my setup.
not looking to rev to 9200 rpms though.. I'm happy with 86mph @ 8650rpm... my limiter is set to 8800

I'm using Maptun directly in Sweden, I've purchase there editing software. They have not enabled it & I have not asked them to do so because they have been modifying the tune. I've been stressed for time & I thought this would be straight forward.

You must have the 300hp watercraft, this is a 255 model stock cam with all of the other RIVA upgrades. It used to rev 8800-8900rpm & go 80mph, now it stops @ 8650rpm & you can see the timing being retarded center cylinder.

The owner of this watercraft claimed speeds that yours is going, I'm to skeered to go that fast