seems to loose a cylinder intermitent

hey everyone thanks for you help with my carbs ahile back. now i have a new less anoyying gremlin to deal with. took the bike out the other day and it rode great just perfect. after leaving the zoo it started loosing power and running as if on just 3 cylinders, then it smoothed out and ran fine again. could spark plugs cause this? i need to change mine anyway. if you need more info no prob thats just the best way i could describe it

 

I had this exact thing happen to my bike.. TWICE...
By all means- check your plugs, wires and coils FIRST.

NEXT- check the plugs into the side of the CDI-box. I had a wire come loose from inside the plastic housing. The wire didn't break, or go bad.. the metal connector just came loose.

NEXT- Pull the CDI-box, remove the cover and look the green circuit board over real good for cracks. Mine had cracked about 3/4" across (2) circuits. I drilled small holes at the end of the cracks and filled them with epoxy to keep the cracks from spreading, then..my brother soldered jumpers across the broken circuits for me. Worked for several years until I just bought a used CDI on eBay cheap..

 

The plug caps screw into/onto the wires. In some types of plug caps, the resistor core/connector also screws in. I discovered 3 of 4 loose on my commuter as I was finalizing the winterization today, one almost about to fall out. I've learned to check them ever since one fell out on the other bike. My 650's plug caps don't seem to have this feature so it may not apply to your bike.

If you have a plug cap that's stripped on the wire (doesn't stop when tightened) unscrew it and lop about 1/4" off the wire and then screw it back on.

And by all means, replace the plugs. It could be that simple.

 

good advice you two. everyting checked out fine. i didnt know the caps unscrewed like that. everyting was tight and the circuit boards were fine. one thing i did find was a loose ground wire near the cdi. i did replace the sparkplugs as well. ill let you know in the future, prob the distant future how it runs. i hate this time of year

 

Me too although I saw a couple of CRF'S in the back of a pickup, at 42 degrees still warm enough for the dirt.

 

yeah i hear ya, but its like everytime i wanna ride it rains, or theres ice on the road. i can do the cold once in a while but mothernature isnt playing fair