2004 RXW Running Issues

[Yamahammer485]

Hey guys,

Going to be doing a carb job on my buddies sled, but just wanted to test the waters for some ideas. The sled starts and idles fine, been a couple tanks through it so far this season. But consistently through the year, its been behaving worse and worse. It would develop a stumble 10km/h off idle and it sounds like its running on two cylinders, just brutal, then if you can nurse it to 60km/h, it sounds like a 4cyl again but theres no power, it wont do over 90km/h. Sled is in excellent shape, ownder by an older guy first and has 6000kms on it.

So far, changed all the donuts on it, put cr10ek's in it. Inspected the coils and DOHC tubes for dark marks or debris suggesting arcing, there was none. Then tested the spark in the dark, excellent spark.

I think its the power jet or the main jets, hopefully nothing electrical, but any other ideas?

 

[maim]

clean the carbs and try some ring free or mechanic in a bottle. might have some carbon binding the rings.

 

[Falcon1772]

Check and see if you're sucking snow or getting ice buildup inside the airbox. I just went through that with mine. I bought mine used and the previous owner put frogskin on the bottom of the airbox snorkel and removed the front toolbox. I removed the skin and added the toolbox back and my problems went away.

 

[Indy]

and if it still runs ruff ina few miles
again

 

[Yamahammer485]

Thanks guys, I forgot to mention, the airbox is perfect, filter is clean and no ice or snow build up in the box or sled, buddy keeps it in heated garage.

I plan to just loosen one side of the carb rack, then flip it upside down and do the bowls like that, I do this on two strokes all the time, same thing on RX?

Will report after its fixed tonight