Question about gutted exhaust (please help)

[05rxwarrior]

I gutted my exhaust as per yamadoggers post http://www.ty4stroke.com/viewtopic.php?t=46386 I noticed that I have a bog now.I noticed that if I rolled into the throttle it was fine but if I hit it from an idle it will bog for a split second. (On a stand with the belt off the motor.)

I was told that because I gutted the exhaust I freed up alot of airflow and I would have to buy a powercommander to compinsate for the change,and if I did'nt I would lean the motor out and blow it up.

Could someone please shed a little insight on this now that I've done it I'm afraid to run it this way..............

 

[canapex]

Yamaha Genesis 150FI motor is the first fuel injected Yamaha snowmobile. With this technology is very little adjustability for air box modifications, etc. If you experience a hesitation in the low end RPM range with the MOD air box installed these are the steps you will want to take to richen the low speed fuel curve. Always make sure the snowmobile is fully warmed up before adjusting any settings. A cold engine will also result in a hesitation!



This will change your low speed fuel mixture much like the pilot circuit on a carbureted model. It does not effect on high speed fuel mixture. The engine will start and run normally in C0 mode so you can change settings with the engine running or on the trail. To return to the normal gauge functions simply turn the key or kill switch off and the gauge display will return normal functions.



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.

 

[apexgt4life]

i have no mods to my apex and have always noticed a hesitation. i thought it was normal and was actually going to put up a post. if im at idle and get on the throtlle it bogs down almos like its going to stall and if i just hold it full it will bog and then kick in like 2 seconds later and rev up. im fully engine stock. if i rev it a little it fine. so whats the deal

 

[apexgt4life]

any one else on this topic, any one else had to reprogram, first ive heard of it

 

[AllagashX]

im gettin my 08 Ltx 0 miles with a bender mtn exaust.
Ill let u know if I get any bog regardless less backpressure. seems only normal tho? less back pressure less low end? no clue tho im new to 4 strokes

 

[Yamaha Man]

I just did the air box mod and I also now get a BOG when I first press the flipper.

 

[87gtNOS]

You guys should wait for the snow to fly before you jump to conclusions.

Yes, it may bog on the stand right now, it may be your imagination toying with you!!

Once the snow falls, be prepared to add some fuel to the low end, as described above, IF it still bogs! It only takes 2 minutes to do this.

Until then, don't worry about the small stuff!!

 

[canapex]

Mine also has the bog since new with no mods at all,it was really bad at times last year.I was told it was a lean bog from the dealer.Some had them and some did not.Now that I have the air box mod I am sure it will be worse but I have yet to try it.

So either a power commander or adjust the factory fuel setting and do some testing when the sno flys,that's what I am doing if I can't get the factory fuel settings to adjust better I will end up buying a commander.

 

[apexgt4life]

bog from the start competly stock, so what is the factory setting and how much should i increase it for low end bog

 

[87gtNOS]

bog from the start competly stock, so what is the factory setting and how much should i increase it for low end bog

got snow yet? Learn the procedure, then once you have snow in the field go test....I would start with +5's!

 

[SledFreak]

From FixPowerSports says, for intake mod, that it may bog for a bit until the computer learns it and it will soon compensate for the more air flow. Wait about 60 miles or so, then if it still bogs, add soe fuel throught the pod. Go up to +10.

 

[87gtNOS]

From FixPowerSports says, for intake mod, that it may bog for a bit until the computer learns it and it will soon compensate for the more air flow. Wait about 60 miles or so, then if it still bogs, add soe fuel throught the pod. Go up to +10.

I did not know our ECU's could learn.......there really are no sensors to learn with!!!

 

[Iceman57]

From FixPowerSports says, for intake mod, that it may bog for a bit until the computer learns it and it will soon compensate for the more air flow. Wait about 60 miles or so, then if it still bogs, add soe fuel throught the pod. Go up to +10.

You need a MAS = Mass Airflow Sensor (which the Apex doesn't have) for the ECU to compensate for changes in airflow. I had a White Knuckle Exhaust and didn't have a stumble but it resonated badly in the midrange. I installed an Excell and now have a low end stumble. I tried the Pod CO adjustment up to + 20 with no success. I have since purchased a Power Commander III. I have a modded air box and have yet to ride it with the Power Commander and air box mod. Most of the time when opening up the intake or exhaust you will need to make fuel map adjustments unless you are already running rich. The Apex midrange is already lean from the factory so quite a bit of fuel was add in the Power Commander fuel mapping to compensate for the increased airflow.

 

[87gtNOS]

I installed an Excell and now have a low end stumble. I tried the Pod CO adjustment up to + 20 with no success.

This was tested last winter, or in your garage just recently on concrete?!

 

[Iceman57]

I installed an Excell and now have a low end stumble. I tried the Pod CO adjustment up to + 20 with no success.

This was tested last winter, or in your garage just recently on concrete?!

Last winter. Rode about 600 miles with the Excell and pod adjusted to +20. I know not to evaluate the sled unless i'm out riding.