New Member, New Probelms :D

[oharris91]

Hey there guys,

Just joined here after recently purchasing my first GS!

I picked up my '81 GS1000G that was somebody's almost finished project but had then sat for a couple of years before I bought it. As expected the battery was toast so I replaced that. I then pulled the tank off and drained what was in there as well as put a half gallon of fresh gas in and sloshed it around then dumped that too. I then pulled the carbs off the bike, pulled them apart and cleaned all the jets, inspected the diaphragms and such (#115 main jets and #40 pilot jets) The previous owner had left the intake side of the engine alone, but had put on a straight pipe exhaust with zero baffles in it. He claims he jetted for this but from what I'm reading #115 main and #40 pilot is standard on these motors? So I picked up some used mufflers and reattached them to the bike as well as a new factory replacement air filter. Plugs are new NGK's and gapped at .030.

So now onto my questions:
1) Are those jet sizes in fact factory?
2) The bike now idles great since the carbs were stripped and cleaned, but as soon as I go to blip the throttle it bogs and almost dies. If you stay on the throttle it will die. This happens even if the choke is on and the RPM's up, still bogs. Thoughts?

Cheers guys, can't wait to get this beast road worthy again and hit the streets!

 

[Nessism]

Welcome!

This website has a ton of info, including a free service manual download so you can look up the stock jet sizes...http://members.dslextreme.com/users/bikecliff/

Also, check my signature for the Newbie Mistakes thread so you can be aware of some common problems.

 

[hillsy]

115 / 40 are stock sizes for your model but don't discount the possibility that the stock jets were drilled out instead of replaced.

 

[JJ]

You mention taking the carbs off and inspecting/cleaning the jets, but did you actually break the rack apart, disassemble them completely, dip the metal parts, probe all the tiny passages and blow compressed air through then to make sure they're clear, adjust the floats, replace the o-rings, re-sync them, and much more?

All the evidence you have given us points to "NO".

Go to the site that Ed (Nessism) provided for you, and do ALL of the past-due maintenance. His signature has a link to a great carb-cleaning tutorial. Order the o-rings from a member here at www.cycleorings.com

The first step in a tune-up and maintenance is to check and adjust the valve clearances. Most of these old bikes are FAR overdue, and the clearances close up with mileage, causing burnt valves, cranking issuse, and more. Look in the manual and find out how to check and adjust your valves.

Mainly, check everything over well, and repair/replace/adjust things as necessary to make it a good-running, reliable, safe motorcycle. Never take a previous owner's word for ANYTHING he claims. As one of our worst presidents said, "Trust, but verify."

Oh yes, thank you for putting mufflers back on it!

 

[steve murdoch]

Welcome to the site, Harris.
Only thing missing from your excellent first post is some pics of your new ride.

 

[loud et]

Also if there are any air leaks in your intake boots you will have throttle issues.
Remove and inspect the intake boots and replace the intake of rings. Cycleorings.com has them AND a full and proper carb of ring kit.
Doing this will assure you have fully disassembled and cleaned carbs and no air leaks on the intake side.
If your intake boots are leaking (o rings) your bike will surely bog and have no throttle response because a flood of air is coming in ahead of the air/ fuel mix made by the carbs.
You have to remove the intake boots to see if the o rings are cracked. Even if they are not cracked they could still have flat/burned spots that are causing air leaks.
This is the time to replace them.
It's just one important maintenance issue with these old Suzuki's but an important one. You can rebuild your carbs 47 times and your bike will still not runderstand for crap if you are leaking there.
Please, follow the full carb rebuild procedure to the letter. Once you get your GS running like new you will be one happy guy.

 

[oharris91]

Thanks for the info so far guys, much appreciated!

Yes I did rebuild the carbs like you said, including stripping them all the way down and dipping them twice in carbs cleaner for a few hours. Replaced all the orings and blew out all the passages with compressed air, as well as replaced the intake manifold orings. The valve clearance is the next thing for me to check and I'll have a look at that today maybe. Is there a kit of shims I can buy to adjust it?

I'll try and snag some pics of it today!

Thanks!

 

[hannibal]

There are some better options than spending $50 on a kit. This forum has a shim club where you can exchange shims for the cost of shipping or buy new ones for $6.50. Also, many Suzuki dealers will swap out shims for free.

 

[kvillebuckeye]

I am also rebuilding an 81 GS1000G. I will not be keeping many of the stock parts so if you need anything just let me know! I've sold some of the stock parts but but still have much of them.

 

[oharris91]

Hey guys so I spent an hour or so wrenching on the bike tonight to try and get it to run better.

I had the carbs apart again to double check float height, as someone I spoke to had said that incorrect float height could cause the bog/die as soon as you apply the throttle. Float height all adjusted within factory spec and it still runs great at idle, especially on choke. But as soon as you apply the throttle it bogs and wants to die unless you let off.

Also noticed if I disconnect one of the spark plug leads from any of the cylinders the idle does not really fluctuate that much, is this normal?

Cheers!