Thread: 5000-6000 variable rpm?!
08-26-2010, 09:01 PM #1
5000-6000 variable rpm?!
Hey guys, I haven't been out much with the ski this year. I took it out 2-3 times perhaps. Last time I was out, the ski was accelerating and decelerating on its own, between 5 and 6k rpm, while holding the throttle steady. Otherwise it runs great. Anybody ever had this issue? How did you go about fixing it? '04 GPR with the mods in my sig. Thanks.
08-27-2010, 08:40 AM #2
I had the same problem with mine, never did figure out what the problem was, good luck and let us know if you find a solution
08-27-2010, 09:25 AM #3
What's your EFI controller set at....you really don't need one with your set up ...your really bone stock...either set it at 1-1-1-1- or remove it and go to original set up...try it and see......is it bogging too?
08-27-2010, 09:39 AM #4
I got the EFI right after taking out the cat. It was bogging down badly when I punched it, so I asked around on this board, and apparently, some skis behave like that when you only change the cat to a d-plate. It solved my problems.
Now, the EFI is at 3 4 1 7. It ran fine like that all summer long last year ,and up untill the last time I took the ski out. I suspect it has something to do with the last pot, the crossover between midrange and high. Maybe a loose connection in the main harness for the EFI, dunno.
08-27-2010, 10:08 AM #5
Well if it ran fine for quite a few hrs with the EFI controller even set that way then its probably not the controller...that's why running it without a controller and checking how it feels plus RPM changes your having, you see if thats the problem... are you able to reach the normal 7000+ rpms..what's your GPS top speed...seeing if there's compression prob.....and just for routine ck your cluster code readings...01 is all normal
08-27-2010, 10:19 AM #6
It just accurd to me, are you using a digital aftermarket tach (tiny/pulse) to come to this RPM change....the stock is impossible to read with all the vibration and sunlight etc...don't go by the that bar stock gauge.
08-27-2010, 10:32 AM #7
Unfortunately I dont have a tach. Instead the change is felt, like a jerk up then down every two seconds or so, back and forth. When I look down at the cluster, I see that the bar goes between 5 and 6000 rpm back and forth. I know that might not be a true representation of the rpms, but it gives me a general idea.
I will go out and get a compression gauge and report what I find. I'll also check to see if there is any codes. The motor is fairly new, 15 hours or so, runs strong all the way to the top 67.7 mph gps. Thanks.
08-27-2010, 11:13 AM #8
Its good to get a hold of the service/repair manual ($10-15 cd rom) it goes over every inch of this ski...In the pic while the ski is idling on trailer with water hose hooked up running ,press the cluster with the 4 white dots for at least 8 secs..the speedo gauge will switch from 0 mph to a code..hopefully read 01..there are 17 codes...generally this is just good tech info to see that all your sensors are working...a good habit .....btw your top gps speed is GREAT for the mods you have, no compression prob there...maybe one of the top tuners or other members will chime in and help..
08-27-2010, 04:24 PM #9
Ok, I've just checked compression and the cluster codes. 125,130,125 and a code of 01. Still clueless. I've also turned down the 4th pot on the EFI down to 6 and reseated the connector. As I'm almost out of oil I can't take it out on the water yet, because as luck would have it, my local shop is out of 2W go figure.
On a side note, forgot to mention my speedo shows speeds waaay over what I'm actually running. Like if I'm doing 60 it'll show 110 and so on. Minor annoyance, but does the speedo wheel on the ride plate have anything to do with engine input, or is it just a dumb speed sensor?
08-27-2010, 04:55 PM #10
Your compression is acceptable its in normal range,,,,these EFI skis have a "lean" spot in that 5000-6000 rpm range...I just had my ECU reflashed ...one of the few improvements done besides timing is improve the fuel curve in that range... my ski gets stronger, I feel in that 5000-6000 rpm range....I talk about this improvement in my "'build" thread in the project section in the Yamaha section.. just saying maybe you never paid attention to it before.....btw forget about the stock speedo.. just dream your going that fast! LOL
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