Thread: Reflashed GPR Powershot
02-25-2010, 03:14 PM #1
Reflashed GPR Powershot
Big thanks to Bill Chapin of R&D for helping me on this.
I was having an issue with my 1390 after switching from the Riva controller to the R&D powershot. I made the switch after hearing from several trusted tuners that the R&D delivers more fuel, especially on the high speed setting(red). The ski ran fine except when I would pull WOT from idle. It was bogging badly & it turned out it was too lean on the bottom with Ross' 40mm TB's & VF3's installed.
Bill is adding a third crossover setting(green/blue) to allow tuning the rpm where the controller adds fuel to the low speed setting(green) and also reprogramming it to add more fuel at peak settings across all three zones. The additional crossover is how the SHO/FZR units are setup, so now I will be able to set the green/blue to add fuel as low as 1000 rpm. Hopefully, that alone will eliminate the bog, but now I've got lots of extra fuel available if needed. According to him, AFR can be measured on the GPR exhaust with an 02 sensor the same way we do it on the SHO engine. Once I get it I'll log the AFR with my LM2 & post it.
He spent a long time on the phone with me & the man knows his shit. Much of what he was explaining went over my head but I definately got an education. Don't sell your GPR's just yet...there's other exciting stuff coming for the 2 stroke crowd!!
02-25-2010, 04:13 PM #2
Good news to here Mark!!
Try locating the wideband O2 sensor where the Cat heat sensor is. I drilled and retapped. It works for a little while but not forever. Do not run the boat without the O2 sensor warmed up tho. Amsoil Intercepter at 40 to 1 helped a little too.
02-25-2010, 04:37 PM #3
What AFR should I be shooting for on the 2-stroke engine?
02-25-2010, 06:30 PM #4
02-25-2010, 07:14 PM #5
new things for the GPR
How about a little hint of what and who's doing performance mods for the "old- 2 stroke GPR"
02-25-2010, 10:44 PM #6
- Join Date
- Apr 2006
- South MS
Very cool Nice to see something new for the 2 strokes.
02-26-2010, 07:55 PM #7
Let us know how it works Mark. Every single unit i have seen gives more fuel on the WOT circuit, but starves the engine and makes it bog in the low and mid.. Only on a 1390 though, 1300s it works great..
02-27-2010, 12:25 PM #8
11-20-2011, 12:27 PM #9
- Join Date
- Sep 2009
- San Diego, California, United States
What ever happened to this thread? It just drops off???
12-17-2011, 11:05 PM #10
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