variation in RPM at idle, throttle lag, backfire

[backcountry22]

First off, love the forums you guys rock. Here's the info. on the sled:

2006 Yamaha Attak (bone stock)

I didn't run it last year and i'm having an issue with all stages of it running. Meaning that it varies at idle between 1 and 1.5k. This happens when its cold and been warmed up. When I try to throttle up it has some serious lag in the throttle, with occasional backfiring. When I let it idle, it seems like cylinder one is falling out and coming back online. I put in a new ignitor from my buddies R1 and it seems like it fires in the same manner. To give you a background on what i've done so far:

As it goes for air: Compression is equal in all four cylinders, the air box is stock and sealed, the intake boots are intact and tight.

Fuel: The injectors are sealed and working (I just replaced all four), the fuel is fresh, the lines are clear and the pump is working (no leaks)

Spark: New plugs, the ignitors have the proper resistance, and all seem to at least be sparking (not sure if one is arching out on the cylinder wall or not but at least the spark is there.

It isn't throwing any codes either so I'm trying to figure out what may be the problem. I'll throw up a vid tomorrow with hopefully some good audio. Any input would be appreciated....thanks dudes

 

[rage man]

Try this maby http://www.totallyamaha.com/snowmobiles ... stment.htm

 

[backcountry22]

awesome, thank you for the link.....i'll try that and see if it works

 

[rage man]

Let us know it it works

 

[backcountry22]

Prior to reseting the CO sensors today, I started coding 84 and 42 i know they are both speed related sensors. I took the belt off so I could get above 4k RPM while working on it so I think this may just be a problem with that. I reset all CO:1-4 with no improvement. Although I tore off the ignition coils from my buddies R1 (same year) and put them on my sled. It sounds much better, but I'm still getting what feels like computer intervention between around 2500 and 3000 RPM. Could this just be the TORS trying to do its job? Wondering if I could reset TORS the problem may be fixed. Anyone think differently? Still backfiring when I mess with the throttle although not as bad, and I think it may just be the computer fighting my throttle inputs....anyway hope you guys had a good weekend, any input would be appreciated.

thanks

 

[4Fighter]

Very well could be the TORS - check your throttle cable routing, and if it speeds up when the bars are cranked either way. This can be real touchy sometimes. I've seen this before - real trip wrecker

 

[vx700xtc]

Possibly obstructed exhaust?

 

[Grunter]

If you said you had an air box mod - I would of mentioned the pod adjustment for more fuel - cause mine did that after the airbox install...

Are you familiar with Ulmer's airbox mod? Check this out if you didn't buy the sled new in case previous owner did stuff.

I've seen loose plug caps do similar if real bad(more common on RX-1's, don't remember seing this on Apex's)

I also had once mixed the 2 last injector connections on the water bottle side which did this - so maybe check that..

Nothing else comes to mind bud!

 

[backcountry22]

Fixed it! One of the injectors was fouled and one of the ignition coils didn't carry any resistance. Got the parts and its running like a champ. Thanks for the help guys, its always appreciated.