Pulled spark plugs to inspect how my gs450 is performing

[dennco2]

My 85 gs450 seems to be running okay. It accelerates okay thru the rpms until it hits about 6,000 and then gets a bit sluggish ... so I don't push it. I doubt it would redline. Today I pulled the spark plugs to see the color and it appears to be running rich especially on the right cylinder. Pic attached. Any observations and suggestions?rich running.jpg

[alke46]

I am no expert by any stretch of the imagination but if that were my bike, I would try adjusting both carbs to get them better balanced. The plug on the left appears to be a tad too lean, while the one on the right does appear to be a little rich.

Just wait, someone with better information will be along shortly to properly advise you.

edit: how many miles are on those plugs?

[dennco2]

I am no expert by any stretch of the imagination but if that were my bike, I would try adjusting both carbs to get them better balanced. The plug on the left appears to be a tad too lean, while the one on the right does appear to be a little rich.

Just wait, someone with better information will be along shortly to properly advise you.

edit: how many miles are on those plugs?

I have both the mixture screws set at 2.5 turns out. That is something to tinker with ... to adjust individually. I guess I could turn the left screw a quarter turn counterclockwise to richen ... and the right screw clockwise to lean? However now that I think about it, before I pulled the spark plugs I was just running the cold engine with lots of choke .... to get volt readings on my multimeter. This gs450 typically only needs choke for about 30 seconds and then ready to go.

The plugs were in the bike when I bought it a year ago. They looked like new at that time.

[dennco2]

I lightly wire brushed the plug tips and reinstalled. As mentioned earlier, I twisted the left mixture screw to richen ... and leaned the right MS with the black plug in picture. 2.5 turns out and then adjusted 1/4 turn only on both. My brief test ride after showed promise .... easy revs to 7,000 in gears 1 and 2. Somewhat fearful to rev to redline. Hate to break it.

[alke46]

Keep checking the condition until you get them the color you can live with. I have seen plugs that look a nice tan color but on my GS, they appear to have more of a gray color.

Also, there should not be any breakage if you take it to the redline. Mine has seen red lots of times.

[alke46]

Have you kept up with the routine maintenance on the bike? Specifically, are the valve clearances in spec? This needs to be done as well as synchronizing the carbs after any changes to the valve clearances.


edit: oops, sorry, I just saw your other post about checking the valves.