Half the Cylinders wont fire

[Evilbassp]

Hi guys, i just got my first bike and im not really that good with mechanical stuff, so hopefully people with better knowledge can help me out. I have a 1979 gs 850. When its running for some reason the two inner most cylinders just cut out randomly. i have tried changing the spark plugs, did the oil and filter (basic up keep stuff). My friend is pretty knowledgeable about bikes and even he is stumped. I took it on the road and it was running perfect for about 15 min and then it got weak and i could not get it over 50, then all the sudden it kicked back in and it was like turbo went off. haha I have tried cleaning the wires to the plugs also. The bike no longer has points on it cause it was changed over. I just dont get what could be causing it to kick in and out like this. Also it has a small oil leak on the heads, so maybe its leaking into the cylinder? I pulled the plugs though and they are burning white. Please help cause im very confused, thanks for the input.

[mike_of_bbg]

Carry one of those replaced spark plugs around. When it fails, pull one of the inner wires and check for spark. Cyls 2 & 3 run off the same coil. Could be the coil or anything back to the crank loose or going bad.

[Evilbassp]

we actually took a spark plug tester to it and went its running correctly it shows full spark to the plug, but the two inner cylinders just seem to drop out, and when we test it then there was weak signal going to it.

[mike_of_bbg]

You could have a coil going bad, bad wires, bad boots, a bad Dyna...

Since you've just joined, you haven't gotten your "mega welcome" yet. BassCliff will probably come around and give you an "official" one (especially if you post an introduction thread in the GS Owners forum), but you'll definitely want to get acquainted with his BikeCliff site:

http://members.dslextreme.com/users/bikecliff/

Here's the mega-welcome (the READ ME link on his site):

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

And in the "electrical odds-n-ends" section there's a part for testing coils:

http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A11

Got a good multi-meter? If not, get one. When the bike is acting up, pull the wires for 2&3 & get an ohm meter reading between them (that's your secondary). Should be about 25-40k (that's thousand - make sure your MM is set to the right ohmeter range) ohms. If it's much higher try unscrewing the plug caps from the wires and testing them end-end. They should be about 5k each. When they go bad they usually go much higher in resistance. New NGK plug caps are about $5 each, and the types you need are listed in that electrical odd-n-ends (at the top).

[Evilbassp]

thanks alot i appreciate the help. I will deff check out these sites to see if i can figure out the problem. As it is right now its driving me nuts. ha

[Steve]

What part of oHIo?

You might be in "striking range" for a visit.

.

[Evilbassp]

akron, ohio

[Evilbassp]

oh and i forgot to mention that the battery is spent as well, but i used a friends and it was basically doing the same thing, but his battery had been drained a few times as well so it was probably weak as well, could this factor in?

[mike_of_bbg]

Definitely. Your charging system might well be shot, and when your battery voltage runs down the ignition stops working correctly. Try running through the stator papers to test your charging system. You can find it from the GSR HOME page, "in the garage". Or right here:

http://www.thegsresources.com/garage/gs_statorfault.htm

[mike_of_bbg]

It's also a good idea to go through your bike and CLEAN, CHECK, and apply dielectric silicone compound to every electrical connection. Under the side covers, under the tank, in the headlight bucket, etc.

[Evilbassp]

looks like im gonna have a very long monday ahead of me haha

[BassCliff]

Greetings and Salutations!!

Hi Mr. Evilbassp,

You'll find lots of GS850G goodness on my little website. Let me share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[Evilbassp]

thank you very much, i love the bike so far. im sure its something easy that needs to be fixed, i just need to figure it out. And i will deff post pics once im done modifying it the way i see it in my head. If anyone else has any suggestions on the problem as well i am all ears. thanks for all your guys help!

[north49]

Your problem may be the 2 /3 coil but more likely the CONNECTOR to the coil. I just had the very same problem and a pretty smart mechanic figured it out in about 15 minutes. He cut the connector out and twisted and soldered the wires together. The problem has NEVER come back.

[Evilbassp]

so i did what you suggested and it deff made the problem alot better, it doesnt do it nearly as bad. But now there is a new problem, my brand new battery drained out of nowhere. any suggestions? ha