fuel injection stumble from idle and up

[max]

Have you apex guys had any fuel injection stumble when going from idle and up ? If so, did it disapear after break in? thanks Max

 

[Bone Daddy]

You may have fouled your plugs

 

[Iceman57]

You may have fouled your plugs

I highly doubt that he has fouled plugs. It's hard to foul a plug in a 4 stroke. If your sled isn't broke in yet that’s probably the problem. Mine did the same thing and after break-in it went away. I do have a stumble since installing an Excell exhaust most likely due to the increased airflow. I have since added a PowerCommander III to solve the low end stumble I now have.

 

[canapex]

Had mine since brand new as well.It never went away.It's a lean bog.
Adjust your low speed setting and your stumble will be gone.



Apex C0 Fuel Adjust:
- Install a wire (or paperclip) from ground to the pale green wire in the connector on the left of the delta box. This wire has no mating wire in the male connector and only needs to be grounded to the Delta Box.


Enter Diagnostic mode:
- With the key and kill switch off, press and hold both "Select and Reset" buttons then power up the gauge by turning both the key and kill switch on.
- Wait 8 seconds and the gauge will go blank except for "DI" in the display.
- Press "Select" to toggle between "DI" and "C0", Select "C0".
- 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 0 should appear in the odometer section
- Press "Select" to increase the number (richer), "Reset" to decrease the number (leaner)
- Example: (10 would be richer) (-10 would be leaner)
- Press both "Select and reset" to chose C:02 and adjust the same as above (must do this for each cylinder)


You will want to go RICHER (positive numbers). Generally up 10 will be enough to get past any hesitation or stumble you may run into.
_________________

 

[newfattak]

Did the Exhaust Mod, now I have a hesitation when nailing the flipper, if I keep rev up at around 3000 rpm, it seems to help when doing standing start runs.
Will this fuel injection adjustment help? never had this low rpm condition prior to modding exhaust, as well it seems to stumble on warm up.
I love the new sound, I hope that this adjustment will solve my problem!!
I have no other mods done, although, I was going to put a couple of Air Filter Biscuts on the Air Box below filter, any comments on this?

 

[RTX DUDE]

mine had a stumble also after pipe was installed. air/fuel ratio confirmed it was a rich stumble not lean as I thought too. so subtract the fuel and see as they are all different. Mine is 11.2 right now, pretty rich yet, but I will lean.

 

[newfattak]

when changing the parameters for fuel, will the display show where it is at when you first start the above noted procedure

 

[Bullitt GT 07]

Stumble

Is everyone having trouble with the stumble? I have a new 07 Apex, about 20 miles on it. My big trip is coming up in a few weeks. Do I have to worry about this ? Also I'm hearing about hand warmer, PTO seals ect. This is not the quality I've always had with BIG BLUE. Any input would be great. Jim

 

[97mach1]

Haven't had any problems with my 07 yet. Only stumble is when cold.

 

[bbjorklund99]

Have you apex guys had any fuel injection stumble when going from idle and up ? If so, did it disapear after break in? thanks Max

Yes, I had a problem with my first tank of fuel. I purchased a 07 Apex GT and noticed that it started and died a 2 or 3 times before it would keep running. I also noticed hesitation when it was warmed up. I ran the tank of fuel through it and it went away. I do not know if it was the fuel that the dealer put in the sled or if it was a break in issue. I have not had any problem since. The sled starts good and the response is immediate when you punch from any speed.

Brad

 

[mbarryracing]

Rode my 06 GT the past few days, pretty aggressive and I am starting to notice a bobble / stumble when I stab the throttle after getting out of it / braking for an obstacle and then want to blip the front end over a home, etc.
It appears to be worse the colder it gets... lean?

Debating adding fuel with the CO settings?

 

[niko]

remember guys that little red light must go out before you boot it or it will stumble when its cold.

 

[littleredsled]

myn stumbles from idle to go i just don't hit it anymore and i wait till engagement then hit it and then there is nothing it just rocks out of the whole all the yamaha 4 stroke i have rode did that

 

[POB88]

when changing the parameters for fuel, will the display show where it is at when you first start the above noted procedure
This is what I want to know.

 

[**sj**]

yes...it will show current setting for each position...1,2,3, keep a record and adjust and if that doesnt work you can work your way the other way : )