Popping & '76 GL1000 - there's more to know, I'm sure

[leonardhcross]

Problem Solved!

Culprit: Frozen mechanical spark advance behind the points plate.

I thought I had checked it way back in about early December. Clearly, the advance mechanism didn't like sitting still in a not-climate-controlled environment for a decade.

It took me pulling a good set of GL1100 carbs off my '82 and mounting them to the '76 and hearing the same pops to be firmly convinced that it was NOT a carb issue.

After cleaning up the advance, it worked like a charm. I then spent the requisite 30 minutes dialing in the split timing on 1/2 and fiddling over and over to dial in 3/4.

I started the bike up, and she ran well. After a brief warm up, I rolled on the throttle to 3k and she was smooth as could be. A few minutes later, we rolled on to 4k. Same.

Thanks for all the recommendations, as always.

Now I just need to extract the GL1100 rack and reinstall the one for the GL1000.

NotSoLil, nice resolution. It would be helpful to see pictures or, better yet, a video of the mechanical advance system repair.. Did you just use a rust solvent to get things back in order?

[redglbx]

Notso,, a couple of random thoughts here..

Since you had reinstalled your gl1000 carbs I had not seen where you had resync’d the carbs once you reinstalled them.. this is a must do thing ! Now since you had previously sync’d them they should be close but everything affects the sync like removing them and installing them ,, ya gotta do that..

Also, I personally would remove the idle mixture screws and spray carb cleaner into those ports, maybe blow compressed air into them. Also once you reinstall the idle mixture screws I would lightly seat them and then turn them all out 3 turns and then resync things (again)…

Also as an aside,, when I was dynoing my 76 with the oe carbs I found that the oe jetting goes from extremely lean on the idle circuit to extremely rich on the mains so I experimented with the jetting and found the following combo gave a more uniform jetting curve and actually made a bit more power.

Idle air jets in the brass elbows : #110
Idle fuel jets, stock #35,,, very lean but keeps things cleaner.
Primary Mains : #65 (stock #62)
Secondary Mains: #115 (stock 120, 1975’s are 125, way to rich)

This jetting setup gives a much more uniform air-fuel ratio across the board along with a bit of a small boost in fuel economy. I realize that this jetting really shouldn’t affect your problem but ultimately should make your bike run better, just something to think about.

I’m kinda going through the same thing on my 76 where it’s been chuffing at idle out the lh exhaust but seems ok above idle. I’ve had this issue for about 5yrs now but with 2 back surgeries and associated problem have not been able to really work on it until yesterday.

My 76 currently has some highly modded 1100 carbs on it and I think it has a plugged idle mixture circuit on either the #2 or #4 cylinders. I pulled the oe 1000 carbs out of storage figuring I would install them to see if they would eliminate the chuffing but wanted to “go” through them first along with repairing some stripped fuel bowl screws but I had to clean my shop first because it’s just been neglected ( a real mess) for the past 5 or so years. So at least I’ve started and hope to finish & install the oe carbs this week.

Anyway, keep us informed on your progress.