82 850 GSL starts won't keep running

[Guest]

My carbs are cleaned and back on, waiting for a new air filter and have the old grungy one in for now. It will start with full choke but won't keep running more than about 10-15 seconds( maybe a bit more occasionally). I have the air screws at 2.5 turns out. Can't give any throttle or it stalls immediately.
Thoughts ?
Thanks

[Nessism]

Did you verify the choke pick up tubes are open? The petcock may be malfunctioning too. Better check that if you haven't already.

[stickid]

Did you verify the choke pick up tubes are open? The petcock may be malfunctioning too. Better check that if you haven't already.

It's a new petcock and the choke pickup tubes are open. I just pulled the plugs and cleaned, they were a bit black not much though,am re-gapping and also checked the compression 1=147, 2=132,3=142,4=140.
I did get it to idle for a while but once it starts to warm up a bit it is more difficult to start.

[stickid]

Well, I had some success. I got the bike running and it will rev smoothly as well. I still have the air screws set at 2.5 turns but will play with that a bit because I can't get it to idle quite right. I put some seafoam in the tank to run through and ran it for quite a while. Still some fine tuning to do on it but I think the new air filter will help. I took some video and will post it on youtube then once I have it there I will post a link to it. I do appreciate all the knowledge on this site and hope that I will be able to help someone one day with some experience as well.
I gotta say though as a Harley rider it took a bit of pushing myself to hear an engine revving that high, it's been a while for this old bike to run but what a power band on this puppy. I am looking forward to taking it for a spin.

[knewel]

How's that for coincidence...?! I open the forum and the first post I see is my issue. I have just put rebuilt carbs back on a 79 Gs850, and, same thing. Would run for about 10 seconds and then die. The longer I wait between starts, the longer it will run, up to maybe 20 seconds. It's like the fuel isn't getting through fast enough. I even made a temporary fuel tank to determine if it was the pet clock. Same thing would happen. Before getting into the depths of despear, headed for the wisdom of the forum. I'll watch this with interest. The good news is, after a full carb clean and rebuild, the bike fired up immediately. It wants to go.

[stickid]

Don't give up. I eventually put some Seafoam in and just kept trying different settings etc. I finally got it go with the choke on full and was able to keep it going . It took quite a while but once it was really warmed up I reset the air screw to 2.5 turns( they were at over 3 I think, and then it just seemed to find a sweet spot. I was ale to take the choke off and the only issue now is idle but I think that is a mechanical issue on the linkage. Be certain to have you air filter in place, that made a difference for sure.
See my video at

https://www.youtube.com/watch?v=HLFzg5LPLbM

[knewel]

Thanks Stickid! Will try that.

[Nessism]

Sounds like it's not running on all four cylinders. You might want to check from a cold start to see if all the pipes get hot.

Burning oil too. You have some mechanical issues. Have you adjusted the valves yet?

[Steve]

Adjust the valves, then sync the carbs.

THEN do your fine-tuning on the mixtures.

.

[stickid]

Not oil, once I had it going for a while I put some Seafoam in it, that's what is smoking, stinky too...lol

[JTGS850GL]

No reason for seafoam if you rebuilt the carbs correctly. These bikes don't take a lot of finesse to get them running if everything is sealed up and stock. Might be an issue with your bench sync or you didn't get everything cleaned out during the rebuild. Like stated above... If you haven't yet, get those valves adjusted BEFORE you mess with the mixture screws and vacuum sync.

[Nessism]

Did you remove the pilot screws and hold them up to the light to make sure the orifice is open?

[JTGS850GL]

Did you verify that the float bowl enrichment passage was clear on all four float bowls?

[stickid]

No reason for seafoam if you rebuilt the carbs correctly. These bikes don't take a lot of finesse to get them running if everything is sealed up and stock. Might be an issue with your bench sync or you didn't get everything cleaned out during the rebuild. Like stated above... If you haven't yet, get those valves adjusted BEFORE you mess with the mixture screws and vacuum sync.

I tried the Seafoam because I was under the impression that it cleans other internal parts as well, I could be mistaken, I have been before ! Just ask my wife.
I did a cold start this morning and it is not running on all 4 . I am going to do the valves and have been doing the research before I proceed. Once I do that and get the new filter in I am sure I will see an improvement.
Any advice on getting the shims , do they come in a pack with the various sizes or?
This has been a journey and a fun learning exercise, I appreciate all the wisdom here , thanks guys.

[stickid]

Yep, did that too. From what I gather it is the valves I need to look at first and that is what I will do.