10-14-2012, 08:01 PM #1
Yamaha FZR stalls out after blipping the throttle while on trailer?
After loading the ski on the trailer after riding, I tend to start it and blip the throttle, nothing crazy just to help empty out the water box as everyone does. Same thing after flushing it at home. Odd thing is that several times, after I blip the throttle, it revs up, but as it comes back to idle it stalls out. I tried adjusting the FPR to see if it helps and doesn't seem to. I provided the BOV a dedicated vacuum/boost line right off the intake manifold thinking that may help. I disconnected the BOV vacuum line but it still did it. I thought about getting a new Aeromotive RRFPR, but thought I would ask for some thoughts before spending money on something that may be unnecessary. Any thoughts or suggestions to why the ski stalls out after blipping the throttle only while it is on the trailer?
10-14-2012, 08:13 PM #2
No doubt it's something to do with your mods, but I couldn't tell you exactly what.
When you blip it does any water come out?
You know it's funny but we blip our FZ's on the trailer too but I have never seen anything substantial come out.
Our Sea-Doos on the other hand have always seemed to hold a lot of water in the box.
10-14-2012, 08:57 PM #3
I would change the plugs first. I had a similar issue with mine last year and a plug change was in order. It may not cure your particular issue but an inexpensive place to start. Stock idle fuel pressure is about 51lbs in case you need a baseline.
10-14-2012, 09:45 PM #4
Thanks for the reference. Is that 51 Lbs while running, or just when the start button is momentarily pressed to start the fuel pump to see the pressure without the ski running? Right now it is about 54 PSI without ski running and about 42 PSI when ski is running at idle. Seems like when I blip the throttle it raises and drops to 38 - 40 and stalls out. I have the R&D regulator. I also have the R&D Powershot, but I know that has nothing to do with it because it did this before installing it.
10-14-2012, 11:06 PM #5
10-15-2012, 05:01 AM #6
I know you stated you're sure it's not the powershot. But can you disconnect power to it just to be absolutely certain? You really shouldn't need a PS anyway with your current setup.
I had the same problem when I first installed my R2 + PS (since reflashed to R3). Removing the PS fixed the problem.
Taking the PS out of the equation will also make it easier to determine the correct setting for your FPR.
10-15-2012, 09:53 AM #7
My own started doing this as soon as I installed an aftermarket ECU. So you can maybe try switching back to stock ECU first and if the problem goes away you know it's the map on the ECU.
10-15-2012, 09:58 AM #8
You may just need to richen up the idle Gus. My AFR was high 13-'s to low 14's at idle with my old R2 tune, & when I would start it on the trailer it would stumble & sometimes shut off, especially when cold. When I upgraded to the R3 they set the idle a bit richer, high 12's to low 13's. & it idles much smoother now. You'll need to adjust it with you FPR because the powershot cannot be used to add fuel at idle rpm.
10-15-2012, 11:31 AM #9
Alright. Thanks for all of the feedback guys. In summary, it sounds like my RRFPR just needs to be adjusted. I tried, but need to dedicate some time again to adjust it. Just to be clear, my 42 PSI idle pressure is with the vacuum/boost line connected. My AFR at idle once warmed up in the water is about 13.5.
When I initially tried to adjust the RRFPR to get WOT AF correct, the idle was so rich it wouldn't idle properly, which is why I had to add the Powershot to be able to add fuel just up top. Maybe the R&D regulator is not rising 1:1 correctly to be able to eliminate the Powershot?
Searching back through the history of Green Hulk I found the proper way to set the base pressure is to disconnect the vacuum/boost line from the RRFPR, start the ski, set the pressure, then reconnect the vacuum/boost reference line to the RRFPR. When you say set it to about 48 PSI with the ski running, should the vacuum/boost line connected or disconnected?
10-15-2012, 11:39 AM #10
I have seen many do that with cam changes and timing gear changes. If it does not do it in the water when you let up i would not worry about it, Don't forget there is no load on the engine on the trailer.
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