2&3 cyilinders running rich

[Anonymous]

i have a 82 gs550m and the 2&3 seem to be running rich. The plugs are black were as the 1&4 are a light brown. I have recently cleaned the carbs and resyneced them. All 4 pipes get just as hot the spark is just as strong on all 4 cylenders i am at a lost as for what the porblem could be. 8O Also there is black smoke that comes out the pipe on the left side of the bike when it is cold.

thanks josh

[Anonymous]

carbs

Coil, swap them if you can and check to see if it shifts to 1&4, also check plug cap connections of all of them, may also be carbs still, float s are correct height? did you clean the jets with any thing that may have changed the orifice size? chokes are right?

[earlfor]

Re: 2&3 cyilinders running rich

I've recently developed exactly that same problem on my 1150. In my case, the carbs are synched correctly, clean and working properly. New coils, plug wires, caps and plugs. Voltage to both coils is exactly the same.
Stock airbox, stock filter and stock exhaust. Float levels matched, drained ad volume checked. Electronic ignition module tested good. Ignition module self test indicates normal. Ignition timing to spec at 32 deg BTDC. Valves checked and adjusted. compression about 140 across the board. Bike uses no oil. In short, nothing on the bike is out of spec, or not working properly. Changing main jet sizes does not change the plug colors to any degree with jetting changes of 4 steps (everything from 117.5 to 125 sizes)
I am in the process of changing ignition timing to 2 deg more advance on the 2,3 cylinders and 2 deg retard for the 1 and 4 while retaining a max advance for either of the specified 32 BTDC. Its the only thing I have been able to think of that may help the problem. Nothing else I have tried has had any effect at all. Carbs have been torn down three times and there is nothing wrong with them. The bike starts, idles and runs perfect. The only thing wrong is the big difference in the 2,3 and the 1,4 plug
colors.

I'll let you know the results. (I make a change, install new plugs, then test ride 60 to 80 miles...every time. Been going through a lot of new plugs. :-) )

Its a 1,4 and 2,3 problem. I do not think it is carb related assuming the carbs are clean and in synch. An ignition split like that of the problem most always indicates electrical or timing.

Does your bike have adjustable ignition timing? If it does, I would check the 1,4 and 2,3 timing VERY closely. Also, changing your mixture screw settings (throttle plate idle position) will do nothing for this problem. It is not happening in a range that those adjustments apply to. Normally, jetting and vacuum levels will control fuel flow and that relates to whether the mixture is rich or lean. In this instance, jetting and vacuum level has had no effect on mixture......another indication it is not caused by the carbs.

Earl

i have a 82 gs550m and the 2&3 seem to be running rich. The plugs are black were as the 1&4 are a light brown. I have recently cleaned the carbs and resyneced them. All 4 pipes get just as hot the spark is just as strong on all 4 cylenders i am at a lost as for what the porblem could be. 8O Also there is black smoke that comes out the pipe on the left side of the bike when it is cold.

thanks josh

[renobruce]

Hey Earl, I noticed in my manual that the #2 and #3 jets are different (from the factory) than 1 and 4. Could this be it?

[earlfor]

2 and 3 run hotter than 1 and 4, so its common to have a jet size a sep lerger in the 2,3 carbs than the 1, 4. Leave them like that.

Earl


\

Hey Earl, I noticed in my manual that the #2 and #3 jets are different (from the factory) than 1 and 4. Could this be it?

[renobruce]

2 and 3 run hotter than 1 and 4, so its common to have a jet size a sep lerger in the 2,3 carbs than the 1, 4. Leave them like that.

Earl


\

Hey Earl, I noticed in my manual that the #2 and #3 jets are different (from the factory) than 1 and 4. Could this be it?

Sorry, what I meant was is your bike set up the same way, or do you have the same size jets straight across, and maybe that's why 2 and 3 were rinning rich on your bike. :P