Ignition Problems 81 GS850

[Mike Curtis]

I have an interesting thing that is happening when I pull the plugs to check the spark.
#4 cyclinder seems to have a good spark # 2 has a so so spark but #1 & #3 will not jump at the electrode but the plug will arc from the threaded portion to the engine.
What should I be looking for is the coil circuit going to ground somewhere?

[LW_Icarus]

the plugs are likely fouled out, or shorted somehow, otherwise it couldn't do that. try new plugs and possibly new resistor caps on the wire ends.

what is likely happening is the plugs are firing deep inside, not at the electrode, or are dead shorted at the base of the electrode, thats the only way the current can get to the threaded portion without jumping the gap first. as for weak spark checkk that you have nearly battery voltage to the coils, alot of the GSs develop resistance in the harness and lower the voltage to about 10 volts, which will usually still run but will give a weak spark.

[Mike Curtis]

Thanks

Thanks ,I've seen the drop of voltage at the coils my plan this weekend to clean all connections and replace the plugs

[JayH]

You might also want to cut back a portion of the wire there at the plug where the cap goes. If the rubber shroud around the cap is cracked you might want to get a new NGK spark plug cap.

[Mike Curtis]

Starting Problems

New plugs did the trick but something happened, bile ran good except that the 1 st & 2 nd carb started to leak gas out of the air intake side.
Thought that the needle valve stuck open not the case.
Removed carbs & everything seems to work but cannot get the gas flow out of the carbs to engine. Engine will run if I enject fuel into carbs and die.
Need some advise here.

[steve4mc]

Lack of fuel flow after the carbs removed.

Mike:
Are you still stuck? It sounds like when you took the carbs off that you didn't get the vacuum line back on that goes to the petcock. You can check the carbs for gas flow by cracking open the plug bolt in the bottom of the the bowl to see if you are getting any gas filling the bowls. You can also turn the petcock to prime and you will get flow if there is no flow in the run position. Good luck.

[Mike Curtis]

Stuck

Somewhat stuck I'm thinking this could all be an electrical problem not enough juice to keep it running. Tonight I will change out the battery and check the float bowl like you suggested.

[Mike Curtis]

Bike will not keep running

There is gas in the bowls but the bike will not keep running with out adding fuel to the intakes. Stuck

[dwarf8]

Tapping

Try tapping on the carbs with the back end of a screw driver.
I know it sounds really dumb but it may free a stuck float.
Whenever I do repairs I go from cheapest and easiest to harder and more costly.

Check all the tubes from the tank to the carbs as step 2.

[Mike Curtis]

Help

Pulled the carbs seems that the floats are free and also the needle valves.
Really puzzling that it will not keep fuel into the engine it is probably a simple thing that I cannot pin down.