GS850G #1 not firing

[wolfleg]

I have a 1980 GS850G and I believe the #1 cylinder is not firing (pipe is relatively cool compared to the other three). Since #4 is firing, does this mean the coil is O.K.? Carburetor is good; getting gas; some spark when #1 plug is tested. Any help will be appreciated.

[firstimer850]

My 80 gs 850 g had the same problem in the number 4 then in the 2. I first took a plug from a hot cylinder and put in the suspect cylinder. In both cases it wound up being bad plugs. You also might inspect all of your plug boots for cracks in the elbow section at the seam. All four of mine provided quite a jolt when a finger was placed on the afore mentioned location. Be carefull or your wife or girlfriend might think you are going to a hair stylist. LOL!

Happy hunting.

[the_journeyman]

I had a '81 650E that had a similar problem with the #2 cylinder. The plug wire had gotten damaged at the end of the boot. I repaired it and the problem was solved ~

JM

[wolfleg]

My 80 gs 850 g had the same problem in the number 4 then in the 2. I first took a plug from a hot cylinder and put in the suspect cylinder. In both cases it wound up being bad plugs. You also might inspect all of your plug boots for cracks in the elbow section at the seam. All four of mine provided quite a jolt when a finger was placed on the afore mentioned location. Be carefull or your wife or girlfriend might think you are going to a hair stylist. LOL!

Happy hunting.

I don't have to worry about the "hair stylist" problem :-)

[the_journeyman]

I don't have to worry about the "hair stylist" problem :-)

This is how I discovered the problem with my 650E. I had a "%#&@ that hurt" moment while checking for a spark ~

JM

[wolfleg]

This is how I discovered the problem with my 650E. I had a "%#&@ that hurt" moment while checking for a spark ~

JM

The wire looks good. Don't see any cracks or wear of any kind. Maybe I have a bad plug, but I have changed that plug several times. Either the plug keeps going bad or something else is the matter.

[the_journeyman]

My problem was internal with the wire. The outer sheathing was fine, boot was fine, but the copper core was broken & only sometimes met & created fire ~

JM

[wolfleg]

My problem was internal with the wire. The outer sheathing was fine, boot was fine, but the copper core was broken & only sometimes met & created fire ~

JM

OOoh, I see. The spark plug wire looks like it is sealed into the coil. If the wire is bad, do I need to replace the coil along with the wire?

Thanks

[the_journeyman]

I'm sure replacing the coil is the best fix, but not cheap. I simply repaired the broken wire because it was broken right where the wire entered the plug boot. The boots on mine would slide up the plug wire where you could get to the copper. Not the *best* solution, but it worked ~

JM

[wolfleg]

OOoh, I see. The spark plug wire looks like it is sealed into the coil. If the wire is bad, do I need to replace the coil along with the wire?

Thanks

Well, the copper piece is o.k. and so is the resistor; at least the resistor measures the same resistance as the one for #4. Can the coil be bad only for #1 and not #4?

[t3rmin]

OOoh, I see. The spark plug wire looks like it is sealed into the coil. If the wire is bad, do I need to replace the coil along with the wire?

Thanks

Yes, unless you want to dig it out, which some people have done with success.

I think Journeman was talking about the wire connection at the boot, though, not at the coil. It's fairly common practice to unscrew the wire from the boot, snip off 1/8 of an inch and screw it back in. That exposes a bit of new wire "meat" for the boot screw to connect with.

Also check the resistance on those boots (search the archives for info on that). They often go bad with age even though they look great. New NGK boots are cheap at z1enterprises.com and are nice looking, too!

[t3rmin]

Well, the copper piece is o.k. and so is the resistor; at least the resistor measures the same resistance as the one for #4. Can the coil be bad only for #1 and not #4?

Nope. If #4 is fine, only the wire, boot, or plug could be the culprit, if it is, indeed, an ignition problem. The same coil fires #1 and #4.

[t3rmin]

If everything in the ignition dept checks out, check for intake leaks and do a carb sync. People seldom realize that out-of-sync carbs can actually produce a cool pipe.

Also check your mixture screw on that cyl. Especially if the pipe warms up under more-than-idle throttle, the mixture screw could be out of adjustment. Of course that same symptom could apply to a sync problem.

[wolfleg]

If everything in the ignition dept checks out, check for intake leaks and do a carb sync. People seldom realize that out-of-sync carbs can actually produce a cool pipe.

Also check your mixture screw on that cyl. Especially if the pipe warms up under more-than-idle throttle, the mixture screw could be out of adjustment.

Thanks everyone! You are great. I will have to do more checking. Will let you know what I find out.

[wolfleg]

Replaced the plug and it works now. Even though the original plug showed a spark upon testing. What is that about? The spark must have been too weak, huh? Lots of smoke billowed out, then cleared up. Pipe gets blue like the others now.

Thanks everyone for your help!