Funky plugs, not sure what to do.

[Anonymous]

Hey guys, I have a 1982 GS650E that I just got running again, I've put about a 100 miles on it, and today I just pulled the plugs to see how it's doing here's what I got. #1 Is white, running lean. #2 Is sooty and black #3 Sooty and black and #4 is tan.

What should I do? Is there a screw someplace I can adjust to try and richen up the lean cylinder?

On another note, the bike also smokes when you start it but it goes away after about a minute, im guessing this would be a valve seal problem. The bike has less than 3,000 miles on it. The previous owner let it sit untouched for 13 years.

[Anonymous]

Oh, I forgot to mention

The carbs have been off before, sent them to a shop for cleaning. I do have access to the airscrews, the caps have been drilled. Also, I checked for an intake leak and there was no change in idle. So I'm guessing the carb is just adjusted too lean.

[IanFrancisco]

If the carbs are like the Mikunis on my bike, the screws are not air mixture screws but pilot jet screws for the slow circuit (idle and just off idle). The fuel and air is already mixed before it passes thru the pilot jets and the screws just control the amount. Used in conjunction with the throttle stop screw, they are just for setting idle and slow speed running. I had trouble getting my bike to idle right until I cranked these out to 2 1/2 turns from 1 1/2. The previous owner had the throttle stop screw cranked up to compensate and the bike would idle down to 2000 rpm and no lower unless I used clutch drag to force the motor down to 1200 rpm, then it would idle. Opening up the pilot jets to 2 1/2 turns out and turning the throttle stop screw back down solved the idle problem. To resolve lean or rich burning from the main jets requires pulling the CV diaphram and needle out and raising or lowering the clip on the needle. Lowering the clip raises the needle and enrichens the mixture. Raising the clip lowers the needle and leans out the mixture.

[KEITH KRAUSE]

For the plug reads, it really depends on the throttle position you were at to get those reads. If just typical riding around town, then the mixture screws could be set incorrectly. They have some overlap effect with the jet needle at lower speeds. You can try counting how much each screw is turned in, keeping a record, and adjust them at different points to see how it effects performance and plug reads. You may try 1 1/2 turns out, 2 turns out...
It's also very likely the carbs need a vacuum synch. Unbalanced vacuum levels will give you those different reads everytime.
It's also possible the coil feeding 2/3 has a weak spark, and a combination of the above is giving you the different reads. Do you get a fat blue spark at 2/3 plugs?
As normal maintenance, I would synch the carbs and if needed, adjust the mixture screws.

[Anonymous]

Im getting good spark to all cylinders, I've never done a carb sync though, does the rack have to come off?

[earlfor]

Uhhhh, no, the bike needs to be running to do a carb synch, so its much easier if they are on the bike. :-)

Earl .....ok, go ahead and shoot me, I couldnt resist. :-)

Im getting good spark to all cylinders, I've never done a carb sync though, does the rack have to come off?

[KEITH KRAUSE]

Uhhhh, no, the bike needs to be running to do a carb synch, so its much easier if they are on the bike. :-)

Earl .....ok, go ahead and shoot me, I couldnt resist. :-)

Im getting good spark to all cylinders, I've never done a carb sync though, does the rack have to come off?

Another of Earls pearls. :roll: