She Lives But Not Very Well

[Tanman]

So Betty fired up today ( 1976 GL1000 ). My first GL so not sure what sounds good and what doesn't but she isn't running right. See attached Video.

So she ticks over but when I connect the Vacuum gauges I have some really odd readings . Again see Video . So gauges are basically saying late valve timing or vacuum leak at manifold. Checked the o' rings at the carb to cylinder connection and all are in place. I also double checked the valve timing and again all appears to be good.

I rebuilt the engine because she was seized. Replacement crank with new bearing and new piston rings. Carbs stripped and cleaned . All fuel and vacuum hoses replaced. However I didn't strip the air chamber . Left the carbs attached and cleaned stripped in place.

Electronic ignition fitted and strong spark all round , checked timing with strobe light and again all appears Ok.

Not seeing the woods for the trees at the moment.

Any suggestions appreciated .

Thanks ,

Paul

[desertrefugee]

Video wouldn’t run for me. A decent bench sync sometimes helps. If one throttle blade is open at idle, you won’t have vacuum in that cylinder.

[quasi2008]

mine were all out of whack like that a couple weeks ago after I replaced the needles in the vacuum slides, one had broke. I had them sync'd up decent but one was just a fuzz off from the other 3. before I knew it I had readings such as are showing on your gauges. I started over with the syncing procedures and it took me about 2 hours but they all came into range of 0.5 of each other. it only takes one to throw the other 3 out the window. at least that's how it worked for me.

[pidjones]

Yep, #3 (what ever you have it attached to) has its butterfly closed. There is a balance procedure in the manual - follow it.

[Whiskerfish]

First thing I would do is swap that vacuum gauge for # 3 to a different cylinder to ensure you do not have a false reading.