1981 GS1000G Help

[I Will Always Be]

I have been lo0king for an old upright cruiser for quite a while. I found this 1981 GS1000G locally for sale for $400.00. Of course it was dark but I went to go see it by moonlight in this backyard and it lo0ks pretty clean so I put a deposit on it. The guy selling it said it stopped running several years ago and he didn't know what was wrong but his neighbor said the outside cylinders are not firing. Already I think coil...BUT....and here comes my questions...Is the 1981 GS1000G an Electronic Ignition or does it have points? Also, can any of you think of any other reason that the outside two cylinders wouldnt fire?

I can't find any info online regarding the ignition system or wiring diagram. I pick up the bike tomorrow and my local dealer has ordered the Clymer manual for me, but I wont have it until late next week sometime and I would really like to tear in to it a bit tomorrow afterno0n. I am betting it is nothing too serious or complicated.

Any suggestions or advice would be greatly appreciated.

I will be sure to post pics very so0n.

Thanks,

-R

[KGB]

First drain every fluid in the bike before trying to start it.

No it is electronic not points.

the cylinders not firing or not getting warm/hot?
carbs not putting fuel to the cylinders will cause a cold condition

[I Will Always Be]

His neighbor was there when i was and he said he pulled the airbox off and sprayed some starting fluid in it and it would idle for 30 seconds or so and then stall. He said anytime he tried to twist the throttle it died immediately and he said that someone told him to take the plug wires off while it was running. He said he did them one at a time and there was no difference in the idle. Even after running it he said you could touch the pipes on either of the outside cylinders and they were cold to the touch...but it you tried to touch either of the two inner cylinders you would burn your fingers immediately.

To further prove his theory he said that if he sprayed the starting fluid in to the two outter cylinder carbs, the bike would not start...but if he sprayed the starting fluid in to the middle two carbs the bike would start and hold an idle for 30-40 seconds then stall.

I will clean the carbs and inspect the jets immediately and of course drain all the fluids and start from there, but electrical is a HUGE weak spot for me.

So since there are no points in this beast is there any ignition problems to consider besides the coils? Also, are there two seperate coils that are responsible for firing the other two cylinders or are they all operated off one coil?

I know this is a long read and I do appreciate your help.

-R

[chef1366]

Signal generator or coil would be my guess. Check all grounds and connections throughout the bike. Make sure you have a good battery.

[I Will Always Be]

Ohhhh, I am glad you said that. He mentioned that the turn signals were not working....are we getting closer?

Thanks a million you guys!

-R

[I Will Always Be]

Here are a few pics of my new $400 toy.

I drained the tank and put fresh oil in this "little" thing and swapped the battery from my 1992 GSXR1100 and low and behold the lights and horn work...but no turn signals.

I pulled the carbs and cleaned the jets which were a lil gunk'd up and sprayed starting fluid in it and true on his word, it held an idle for 20-30 seconds and then stalled. Anytime I tried to rev the engine it would die immediately. The outside two cylinders are not firing.

So tomorrow sometime I will inspect all wiring as best as I can including the grounds. My question is are there any other reasons besides COIL that would cause this thing to run only on 2 cylinders?

Thanks guys,

-R

http://i75.photobucket.com/albums/i306/IamRip/GS1000c.jpg

http://i75.photobucket.com/albums/i306/IamRip/GS1000b.jpg

http://i75.photobucket.com/albums/i306/IamRip/GS1000a.jpg

[earlfor]

[quote=I Will Always Be
My question is are there any other reasons besides COIL that would cause this thing to run only on 2 cylinders?

Thanks guys,

-R



Most likely suspects would be the coil or the 1-4 side of the ignition module.
If its running on 2,3, you could swap the 1,4 coil to the 2,3 plugs. If it still runs on 2,3, then you know both coils are good. If you have power to the harness leads on the 1,4 side, then you know the 1,4 coil isnt the problem.
That leaves the ignition module or crank triggers.
Carbs could be varnished and blocked, but usually if that is going to happen, it will be the 1,2 carbs varnished up since the bike sits on the kickstand causing those two to be most prone to that problem. A varnishing problem would be unusual simultaneously on the 1,4 carbs.

Earl.

[I Will Always Be]

Earl, thank you. I will try that tomorrow sometime and report back.

This site is great. I appreciate the feedback I have received thus far.

-R

[dpep]

It sounds like the guy had the airbox off while he was spraying the starter fluid and trying to get it to idle. That WILL NOT work with these bikes. The G models in particular must have a proper air filter and a well sealed air box. Must have. That would explain why it died everytime he opened the throttle.

[I Will Always Be]

dpep, thanks for that bit of info too. I am not much of a mechanic so all of these tidbits are really piling up to getting this bike running again so0n.

I will report back tomorrow about the coil.

-R

[I Will Always Be]

Ok Guys, I need help again.....

I swapped the 2,3 wires to the 1,4 cylinders and it wouldnt fire at all.

I also swapped the 1,4 wires to the 2,3 cylinder and it wouldnt fire.

So I am don't know if my 1,4 coil is bad because the 1,4 cylinders wont even fire when the 2,3 wires are running to them.

There is a red and white wire that is a lil charred where it connects to another red/white wire. This wire runs to the under side of the bike where it is harnessed together with 3 other wires and they all plug in to a metal box that is slotted.....like with fins. Sorry I am not much of a mechanic. I can take pics if that will help anyone who wants to help me.

....and I still have no turn signals.

Thanks in advance,

-R

[Bananaman]

Take out the spark plugs and have a look. See if they are wet and therefore gettin fuel.
Then stick a plug into a lead and short it against the cylinder head. Crank it and see if your gettin spark. Try all the leads.
If you have a compression tester do a test while you have the plugs out.
If you have a multimeter check the resistance of the plug end caps.

That should keep ya busy for awhile

[chef1366]

You need to switch the wires going to the coils themselves under the gas tank and then the plug wires. If you just switch the plug wires you're just running off time.
One coil controls 1&4 The other 2&3. When you switch the wires going to the coils (not spark plug wires) they then switch out. Then switch out the 1&4 spark plug wire and 2&3 spark plug wire.
The finned thingy is your rectifier/regulator. Sounds like it's burnt..

[slob]

Same problem here, I have a couple of 82 1100G's and chased the fault for a while until I found the plug leads has tiny cracks in them. I used to change plugs and that would fix it for a while. So I cut the lead back as far as I could. I'm told I can't change the leads and should get some coils from a later model that have changeable leads.