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Major bog off idle with new parts (Ultra-Q, Drag&Fly,etc

B

barto

Newbie
Joined
Jan 5, 2006
Messages
17
Location
Southern Maine
Since our snow disappeared (Maine), I spent the weekend tinkering with the Apex (2006 RTX). The sled already had the cr10ek plugs all last year. I installed the following:

1) Skinz Ultra-Q exhaust (these things sound awesome)

2) Drag&Fly Clutch weights (Setup per baseline in Heel Clicker Book)
Shoulder: 4.7g
Center: 3.2g
Tip: 0g
Overdrive: 4.2g
Spring: White
Secondary: Stock @ 3-3

3) Dayco Ultimax 3 Belt (138-4432 U3)
What is the difference between this belt and the Carlisle? XS-805

Symptoms: Now, my sled idles around 1600 (not sure what it should be), idles up to 2000, down to 1600, up and down.

Whack the throttle, it bogs way down, like it's going to stall, then increases and starts to haul. Engagement is over 4000 with the current setup.

Any thoughts or advice?
 

You need to adjust the low end of the EFI. Allen Ulmer (srxspec) has a great thread that has the instructions on how to do this. If I can find it I'll post a link, unless Allen can chime in????
 
Ulmer Racing
43230 290th St, Menno SD 57045
Phone: 605-387-2833 Fax: 605-387-2883 Email: Srxspec@Gwtc.net
www.ulmerracing.com

Stealth MOD Air Box

The 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.


This will help with the off-idle stumble, but as Turk said, you may need an EFI box. I did the mod per this post, and it runs fine until I hit WOT, then it studders. Airflow modifications will make the engine run leaner than stock, and cause a need for more fuel.
 
Thanks for the ideas, guys!
I had some thoughts about the fuel mixture, but I have not been hearing much from anyone else who has added an aftermarket exhaust as far as leanness. I though it might be the clutching. I have got no ideas on these Drag&Fly's. The book doesn't tell you which hole in the weight does what (i.e. - which one affects engagement, and do I add weight to lower engagement, or the opposite).
 
After some consideration, I can see that the bog is not clutch related. How can the clutch affect the idle? So it must be fuel mixture. It is strange that not many of the other exhaust users out there have complained about this. I have heard a lot of squawk dealing with airbox gutting, but not much on exhaust.
 
I adjusted the low-end mixture with the following results:

I started at 8, and it ran good without the stumble and bog.

I set it to 10 and it ran without stumble, but as it idled, it sounded burbly and slowly lost RPM and stalled.

I set them to 6 and it ran more crisply, but without the hesitation.

I am leaving them at 6 for now.

It does make me curious about the rest of the fuel map in the higher RPM ranges, however. I have not done any high RPM runs to find out.
 
I wish I had invented them. They are a sweet piece of engineering. The thing I don't know is how each of the four adjustable weight locations affects my RPM and overall performance at different RPM and loads. I have them setup right now according to the chart in the enclosed manual. This is pretty close, although my engagement is a bit high (4000 rpm). To lower it, I think I have to load even more weight onto the 'shoulder' hole on the weight. I already have a ton of weight there.
 
barto said:
I wish I had invented them. They are a sweet piece of engineering. The thing I don't know is how each of the four adjustable weight locations affects my RPM and overall performance at different RPM and loads. I have them setup right now according to the chart in the enclosed manual. This is pretty close, although my engagement is a bit high (4000 rpm). To lower it, I think I have to load even more weight onto the 'shoulder' hole on the weight. I already have a ton of weight there.
Click to expand...
They sound interesting except for the engagement...4,000 is way too high for me. I had the high engagement issue with Randy's old Heel Clickers on my 670. It would drive me nuts along with the inconsistant shift...eventually threw them out and went back to stock. I'm using the 48g Heavy Hitters on my Attak...engagement is 2400rpm and there's no stumble. Good luck!
 
Barto, Change to the black primary and you should lower engagement 4-500 rpm. Top end is about the same. I think it is maybe 10-20 lb more.
 
Thanks for the advice; I was thinking about doing that, but I wasn't sure what to do about the rest of the weight locations on the arm.
 
Engagement is at 4200 rpm or so, top end varies depending on which belt I use.

I over rev a bit with the stock belt (10,700+)

The U3 and 805 are both below 10,500.
 
I would put in the black spring which should drop engagement to about 3800. Keep the 805 belt and try it. The spring will also bring up the rpms on top a little. You will probably need to drop a little weight out. I would try to run it so it comes in at 10,700 and finishes at 10,800 or 10,900. I would also buy a key to advance the timing. It is cheap power.
 
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