CB350 burning plugs

[Dragonfish]

I need some advice. It was running pretty great a few weeks ago, then it sat until today. I got it to start but it was hard! Then it really just wouldn't stay running. I could feather the throttle to keep it running but it would eventually die. I pulled the plugs and this is what I found:

The left plug came out of the left cylinder. That side's muffler is basically gone, so it's got wide open air flow. The right plug looks much better, just a tad wet. I cleaned them up and it fired right up! For about 2 minutes. Pulled them again and the left plug looked totally sooty again. Any suggestions? From what I read that should mean the cylinder is running rich but I would think that with the hole in the exhaust it would be lean. The only thing that changed during that time was I installed the air cleaners, I had been running it without any up till then. The bike has otherwise been set up to factory specs for timing, float height and air/fuel screw. The only thing I haven't done is adjusted the lifters. Help?

 

[boykinjw]

Re: CB350 burning plugs

When you added air filters did you put the factory setup on or did you install pod filters? If you went from open carbs to factory i could see that causing a rich mixture.

I didnt have an issue with the soot but i was killing plugs every couple months. They would just stop working one day. I moved up one notch on the heat range and havent lost a plug in almost a year. So you may want to look at that as well.

 

[Dragonfish]

Factory set up, came with the bike. They do look pretty dirty. According to the manual, if it is sooty I should go one plug lower in heat. How do I find out what plug that is? Would that be an NGK 7ES? I have the B-8ES in it now. Thanks!

 

[Dragonfish]

Oh, and should I ditch the factory filters for some pods? I'm also going to swap out the muffler as soon as I find a factory replacement. The only one on ebay (oem) has holes in it.

 

[Dragonfish]

A little more research and I found several resources that list a clogged filter causing carbon fouling. Looks like its time to pick up a new filter.