One cool header, faulty troubleshooting, and setting timing.

[gwhunran]

I am still having a bit of trouble with the 79GS1000L. After replacing the carb boots/manifolds. I still have #3 header much cooler than the rest. When the spark plug is removed reattached to the plug wire, I get spark. The carb boots are not leaking.
I damaged my starter clutch this past weekend while trouble shooting this problem. I swapped the wires on plug #2 and #3 trying to see if the problem followed the wire. What I got was the motor running for another four or five seconds then making a bad sound and dying. Switched the wires back around the right way. When trying to restart heard a grinding sound coming from around the lower left side. Then starter started making free running sound, no engine turn-over. Push cranked the bike and it seemed to run fine, of course still had cool number three header. A couple of days later I opened up the left side, stator cover/starter clutch area and found all three big bolts holding the starter clutch together had sheared completely. 1. What exactly happened switching plug wires two and three to shear these three rather large bolts? 2. Can the timing be causing pipe three to be cool and pipe two to be running fine. I have a Dyna-S ignition and had no problem setting 1&4 exactly as stated in the instructions. I used a timing light, not gun, lined the index mark up and set it to light exactly on the mark and go out just before or after the mark, I can’t remember now if it was before or after. The problem is I could never get the light to work the same way on 2&3. I would light on the index mark but would stay lit way past the index mark and moving the “pick-up” (the little black thing held in place by two Allen nuts throughout their complete range made no difference. I don’t have nor do I know how to use a timing gun. I have searched and read some of the post about adjusting timing but don’t follow some of the jargon and without illustrations I don’t know how to decipher some of the jargon used.
I have ordered new bolts for the starter clutch from bike bandit and have a used starter clutch, gear, and starter on the way from ebay, because at the time I didn’t know exactly what in the starter assembly was broken, and after seeing the new prices and finding starter parts on ebay ending within hours I bought them all for much less than what one new starter would have cost.

[rek]

i had the cool cyl thing on my gs1k also. mine would not fire at idle but, if i went down the street it would get hot. i went thru and hit all the carb passages again especially the idle circuit and it worked great. the idle circuit is very small and any llittle thing will stop it up. try reving a little to get into the needle jet and see if it is now working. might help might not. i too chased the ignition for a bit until i found it worked at a higher rpm.

as for the starter clutch my gs has been good but the kz went out and they are almost identical. i followed several tips from the kz'ers including getting some slightly longer bolts from ACE and using a combo of red loctite and locknuts on the inside of the stator to ensure they don't back off and get sheared again. works great.. driving it today!!
good luck.

[argonsagas]

To answer your query regarding switching wires between cylinders 2 and 3, there should be nil difference. This is because cylinders 1 and 4 run off one coil and 2 3 off the second one. If your wiring is done in that manner then you should look for some problem with the plug wires.

[gwhunran]

Cylinders 2&3 do indeed run off one coil, 1&4 off the other. What I did was put the plug wire from three on two and the plug wire from two onto three with no change in coil attachment. Both wires are on the same coil. I was trying to see if the problem would move to the other header, thus telling me if the wire was bad. One thing I failed to mention is that when I did this, I had earlier loosened the bolts holding the coil to the frame so that I could more easily check the wires going into the coils and had not retightened the bolts before switching the wires and testing.

I would really appreciate it if someone could address the timing question I had in the original post. As I mentioned in that post I have searched and read some of the post about adjusting the electronic ignition but do not fully understand some of the jargon used with no illustration explaining exactly what is refered to. My instuctions that came with the ignition did not illustrate it and my Haynes manual only addresses the stock points and condenser.

Thanks,
Richard

[ccratin]

Check your petcock. On the GS fours, the vacuum line goes to #3. If the petcock diaphragm is leaking, it can be pulling gas through that vacuum line into your #3 carb, making it extremely rich. It will foul a plug very quickly with that situation. If you put the petcock on prime and disconnect the vacuum line from the petcock and plug it so as not to lose vacuum, the cylinder should run right. This assumes you have a good spark plug at this point.

If you find it is the petcock, the rebuild kits are available from Cycle Re-Cycle.

[gwhunran]

Vacuum line is hooked into carb#2 and that plug does look a little rich, but plug three looks just right.

[Ghostgs1]

Hi Richard, The vacuum for the petcock needs to come from the #3 carb. The other 2 lines from carbs #2 & 4 are vent lines and do not pull a vacuum. They should be routed up to the area of the top of the air box. Good luck, Ray

[gwhunran]

I had a vacuum line from the pecock attached to a vacuum nipple on #2 carb, I switched it to the nipple on carb #3 and ran it a little at idle today. Header three still cool. I don't have any of the other lines mentioned mainly because I am running with K&N Pods, no airbox.
It has been raining all day and I haven't been out testing yet other than running it at idle some after working on the starter clutch/stator assembly.
I had sheared the three bolts somehow that connect the starter clutch to the metal piece with magnet inside that rotates around the stator.

I am still hoping that someone can enlighten me on the proper way to set up the electronic ignition timing on the Dyna-S. I followed the instructions and had no problem setting it right on 1&4 with the index marks on the bike. I just couldn't get 2&3 to work the right way with their index marks. Timing light stayed lit when at the index mark and continued to stay lit way past it no matter where I positioned the "pick-up" for 2&3.

[damnitall]

I didn't see anyone suggest this yet, but it worked for me.

After working on the engine once (valve adjustment) it had a cool pipe. It was intermittent, some days the cylinder fired fine, other days it didn't. Out of desperation I got some spare fuel line, cut it to length, split it, and covered each plug wire. Since then the problem has been cured.

Don't know if the insulation on the wires had weakened with age or if I routed them poorly, but adding insulation helped.