T
Anybody experience a hesitation? 2009 Nytro, happens at any rpm. Hit the throttle and it hesitates. Dealer cant fix, yamaha says its normal. What do you guys think. Also all stock.
Nytro Hesitation
- Thread starter threecar
- Start date
A
hesitation
I have two 08 Nitro MTX sleds. They both have a slight hesitation or cutout.
I usually notice it while under throttle going up hill. I think it is just a hickup in the electronics that control the fuel injection. The fuel injection systems on the bikes and sleds is not as sophisticated as the systems found on our cars and trucks. I don't pay it much attention.
I have two 08 Nitro MTX sleds. They both have a slight hesitation or cutout.
I usually notice it while under throttle going up hill. I think it is just a hickup in the electronics that control the fuel injection. The fuel injection systems on the bikes and sleds is not as sophisticated as the systems found on our cars and trucks. I don't pay it much attention.
have you tried dropping your CO's to -15 or 20 my turbo nytro had the same issues and that seemed to fix it. Also you might have the dealer check your fuel pressure found that when it was over 40 it made it worse just something to look at.
O
I'll have to ask the uneducated question - what are the CO's?
One thing I read somewhere else that helped a bit was to tighten up the throttle cable a bit (to take out a bit of slack). This did seem to help a bit on my MTX.
Still is a very annoying problem, especially when you have your weight forward at low speed and it cuts - have almost tea kettled numerous times.
One thing I thought to check but haven't done yet is to test the throttle position sensor. Is it possible that some of these are defective and may have a "flat spot" where the signal to injectors goes back to idle? Should be fairly easy to test, as I assume that resistance should slowly increase as throttle opens. If there are any anomolies, that might suggest a problem. Perhaps crazy...
Any thoughts?
One thing I read somewhere else that helped a bit was to tighten up the throttle cable a bit (to take out a bit of slack). This did seem to help a bit on my MTX.
Still is a very annoying problem, especially when you have your weight forward at low speed and it cuts - have almost tea kettled numerous times.
One thing I thought to check but haven't done yet is to test the throttle position sensor. Is it possible that some of these are defective and may have a "flat spot" where the signal to injectors goes back to idle? Should be fairly easy to test, as I assume that resistance should slowly increase as throttle opens. If there are any anomolies, that might suggest a problem. Perhaps crazy...
Any thoughts?
Found this on another post: how to adjust the CO
Nytro:
1) Ground the pale green wire with the white connector in the nose cone area.
This wire has no mating wire in the male connector and only needs to be
grounded
2) Enter Diagnostic mode:
-Key and kill sw off, press and hold both "Select and Reset" and then
power
up the gauge (key and kill on)
*I leave the key on and just use the Kill Switch
-Wait 8 seconds and the gauge will go blank except for "DIAG" in the
display
-Press select to toggle between "DIAG" and "C0", Select "C0"
*If there is no selection, recheck your ground
-Press and hold both "Select and Reset" 3 seconds
-Gauge will display "C:01", (this is where you select which cylinder you
want to adjust)
-Press and hold "Select and reset" 3 seconds and a number will appear at the bottom of the screen, (will be 0)
-Press "Select" to increase the number (richer), "Reset" to decrease the
number (leaner)
*adjust it to read 10 for richer, -10 will be leaner
-Press both "Select and reset" and chose C:02 and adjust the same as
above,
you must do this for each cylinder
This will change your low speed fuel mixture much like the pilot circuit
on a carb model, there is little or no effect on high speed
The engine will start and run normally in C0 mode so you can change
settings with the engine running or on the trail
To reset simply turn off the key or kill switch and the gauge will return
to normal"
Nytro:
1) Ground the pale green wire with the white connector in the nose cone area.
This wire has no mating wire in the male connector and only needs to be
grounded
2) Enter Diagnostic mode:
-Key and kill sw off, press and hold both "Select and Reset" and then
power
up the gauge (key and kill on)
*I leave the key on and just use the Kill Switch
-Wait 8 seconds and the gauge will go blank except for "DIAG" in the
display
-Press select to toggle between "DIAG" and "C0", Select "C0"
*If there is no selection, recheck your ground
-Press and hold both "Select and Reset" 3 seconds
-Gauge will display "C:01", (this is where you select which cylinder you
want to adjust)
-Press and hold "Select and reset" 3 seconds and a number will appear at the bottom of the screen, (will be 0)
-Press "Select" to increase the number (richer), "Reset" to decrease the
number (leaner)
*adjust it to read 10 for richer, -10 will be leaner
-Press both "Select and reset" and chose C:02 and adjust the same as
above,
you must do this for each cylinder
This will change your low speed fuel mixture much like the pilot circuit
on a carb model, there is little or no effect on high speed
The engine will start and run normally in C0 mode so you can change
settings with the engine running or on the trail
To reset simply turn off the key or kill switch and the gauge will return
to normal"
M
Chances are it's the TORS system. Disable it and see if it helps.
R
P
Sorry Snowest, no disrespect to your magazine, which I read religiously but there is a great write up in the Snowtech magazine in this months issue, that covers this exact problem, and also provides the fix. They cover the issue of slack in the cable that is possibly causing the problem. Give it a read and see if it fits your bill. Just trying to help.
W
woodies
Guest
i get that once in a while to, also sometimes the engine doesn't want to idle down. i have a tether and no kill switch, the flipper has loose cable, wierd? the tps is disconnected.
M
Slack in the cable will cause the TORS system to function erratically... that was the point. If you disconnect it, and the problem goes away... you can diagnose the problem from there.
O
I'll certainly check out the TORS system to see if that's making a difference, but my hunch is that it's deeper than that. Correct me if I'm wrong, but a TORS malfunction will act to cut the ignition circuit, thereby killing the motor if it's at low RPM, whereas this hesitation problem seems to be between idle and low throttle only. Just one man's opinion...
Love the Nytro, but is seems so "rough" compared to the "refined" feel of my former vector. Same motor, but that carburated feel was absolutely silky smooth on the bottom end like the RX-1's and Apexes. Speaking of which, why don't we see this problem on the Apex, it's the same type of FI system I'm sure...
Love the Nytro, but is seems so "rough" compared to the "refined" feel of my former vector. Same motor, but that carburated feel was absolutely silky smooth on the bottom end like the RX-1's and Apexes. Speaking of which, why don't we see this problem on the Apex, it's the same type of FI system I'm sure...
R
that sounds like the isc motor....which has the, i dont know what yamaha calls it, but anti back pressure thingy built into it. makes it feel like more like a two stroke and less like it wants to toss your a$$ over the bars when you let off the flipper.
T
Great info guys. keep them coming. Maybe with all your help the dealer and manufacturer will recognize my nonexistent problem along with all of yours.
T
Anyone else have any input?
O
Hey Threecar,
Been really busy lately and haven't even had time to think about trying out the suggestions yet. I'd like to try them in the next week or two to see if anything helps. Hopefully some others will throw in some more comments...:beer;
Been really busy lately and haven't even had time to think about trying out the suggestions yet. I'd like to try them in the next week or two to see if anything helps. Hopefully some others will throw in some more comments...:beer;
B
I had the slight low end hesitation, put a skinz silencer on it and it made it much worse. Turned the co up from 0 to 10 and that seemed to take most of the bog out. Going to try the co a little higher to try and clean it up. Jim
