Carb Questions

[Tinner]

Is it odd that I just changed the plugs and cyl. 1&2 the plugs were Very black and Carboned up and Cyl. 3&4 were beautiful not rich or lean what should I do for this problem it runs ok but sometimes it acts like it has a miss in either cyl. 1 or 2 or maybe both.
what do I look for???

[Anonymous]

Because both 1 & 2 have carbon then it would seem odd that both 1 & 2 carbs are both off and 3 & 4 are ok. But its still possible that this is whats happening. The carbon means that it is running rich. Is it like this only at idle? or at all throttle positions?
You should try running it at different throttle positions and then pulling the plugs and checking the coloring. It might only be at idle, or it might be only in mid range.

Are you running points and condensors? It is possible that your condensor for cyl 1 & 2 is not good.

[Tinner]

thanks for the reply I am new to wrenching on GS Bikes and to be perfectly honest I don't know if it has points or not it is a 1980 GS1000 GL and I am learning quickly as I am starting to restore a 850 gl for my wife so I am a fast learner I have also ordered a clymer manual and it will help I am sure
thanks

[earlfor]

Re: Carb Questions

Your bike being a 1980 has an electronic ignition. Whether it is electronic ignition or points and condensors, the ignition system and coils work in matched pairs. 1 and 4 cylinders is the left coil and left sensor/pickup on the crankshaft, Cylinders 2 and 3 are the right coil and the right sensor on the crankshaft.

Since your problem is with the 1 and 2 cylinders, it cannot be an ignition or electrical problem. It cant be a clogged airfilter because that would soot all four cylinders. Its not a petcock problem because you have enough fuel flow to blacken the plugs. YEP.......carb problem :-)

Since you are not riding the bike at idle speed, it is not your idle mixture screw settings responsible for this condition.

1980 is CV carbs There are two probabilities. The floats are set too high in the bowls on the 1 and 2 carbs. The 1 and 2 carbs are not synchronized correctly. (for this condition to occur, when checked with a vacuum guage, the carbs would have too much velocity and consequently be drawing too much fuel .

Reset your float heights. Synchronize your carbs.

Earl

Is it odd that I just changed the plugs and cyl. 1&2 the plugs were Very black and Carboned up and Cyl. 3&4 were beautiful not rich or lean what should I do for this problem it runs ok but sometimes it acts like it has a miss in either cyl. 1 or 2 or maybe both.
what do I look for???