My first post....carb question??

[Otto]

Hi All
I have under the influence of a lot of beer purchased a GS 1000 (E?) from 1980, for free!! Lovely! I am trying to get it running. At this point i have got the camshafts renovated/new shims, gaskets and so on, so i have lot of nice compression. I have fixed the high voltage parts, and lots of nice sparks in the right timing. Me and my friend aplpied some gasoline and pushed the lady down the street....and Kapow! it started ....somehow....We can keep it running with the chooker on, but when we try to turn the gasbar it dies...i have tried to read some of the carbthreads, but we are so much beginners on these Mikuni 34 aircontrolled carbs, that i would like to ask some (maby rediculous) questions here...It is ok to laugh! My theory is that the vacum pistons dont move at all when we give gas. We have observed to plastic studs on each side of the fuelhose inlet. What are they? what do they do? should there be fitted hoses on them? should they be connected together?
Hope you have nice advices for 2 absolut beginners in this (hopefully) great world of GS.
Best regards
Otto, Copenhagen

 

[Billy Ricks]

If it sat for any length of time the carbs need to be cleaned. The slides are vacuum operated so they won't open by twisting the throttle. If they don't move with the engine running then the diaphrams they are attached to are shot. The studs you are referring to are vents. If the bike has individual filters on the carbs they shouldn't have lines to them.

 

[Billy Ricks]

Here's a link the the sites carb cleanup section.
http://www.thegsresources.com/gs_carbrebuild.htm

 

[Otto]

Thanks for reply, i have standard (box) airfilters i cant se where the hoses should be attached. The bike has been running for two months ago. I had the carbs of, an pressed the four pistons up, and they all 4 came down again nice and vacumlike....

 

[Billy Ricks]

The vent lines usually just drop down behind the crankcase about 6". The vents are there to equalize atmospheric pressure in the bowls. Check to see if the throttle plates are all set the same and open together. You have to pull the carbs to see them. The cleanup series should get you on the road.

 

[Otto]

Yes Thank you for the link...i will get right at it!

 

[Guy]

While you have the carbs off, take off the inlet stubs from the head and replace the o-rings if they haven't been done already. These are a common cause of vacuum leaks. Good luck.

P.S. Jeg skal til Kobenhavn paa GS i naeste paaske. Ka' ikke vent!!

Guy.

 

[Cajun Cycler]

Those "Inlet Stubs" are carb boots and don't just check the O rings, look at the boots and inspect for cracks or if the boots are brittle. if they are replace them. one of the major causes for an engine with good compression to not run well is air leaking into the intake manifold before the carbs.

 

[tconroy]

Do replace the carb boot and 0 rings.I just did this to mine and it made a world of differnce.Idles great ,less noise and runs smoother,(sounds like a beer comercial) Got rid of my rattle too.

 

[Otto]

I have exploded my carbs yesterday, they generaly looks nice and clean, but i am going to replace all O-rings in the reassembly process. The boot? you are reffering to, what is that? is it the hole in the carbs for the stubs? and how to replace them?
Thanks a lot for interest!
Otto

 

[Cajun Cycler]

The boots are those rubber isolators that go from the cylinder head to the carb. Black and bolt to the cylinders themselves. four cylinder engined Suzuki's have 4 of them. Their not cheap, I got them for $25 a piece but they are totally necessary for a properly operating engine.

 

[Otto]

Ah! ok, they look nice and firm on my bike, i cant imagine any airflow there....but just to be shure, cant i put some liquid gasket on the surfaces to make it firm?

 

[Billy Ricks]

They have O-rings between the head and manifold. You should be able to find something to fit at an auto parts store.

 

[Otto]

Just a quick update on the projekt... After looking at the bootthread 5 or six post up\\/ i decided that my O-ring whas shot also.... so now i have bought and fittet new ones... urgh! 24 $ for 4 rubberbands.... so now i am desperat waiting for carbkits from Germany...
Regards
Otto

 

[Otto]

How to examine the airmembrane in carbs??

How to examine the airmembrane in carbs??

I have reasambled one of the carbs, and i am wondering how to check the airmembrane that controls the "fuelpiston" When i looked at the membrane it looked ok, no cracks and so on. On the airboxside of the carburettor there is a oval hole in the toppart. If i blow air in the hole with my mouth the piston moves up and stays up, until i take the pressure of. If i do it again and at the same time ingage the chooker, i can hear wind whistling, and i have to blow more to hold the piston up. Is that a way to check the piston/membrane? Should i be able to make i move some how with air from the engineside of the carb.?
Sorry for bad spelling, hope you understand what i meen.
Otto

 

[Guy]

If i blow air in the hole with my mouth the piston moves up and stays up, until i take the pressure of. If i do it again and at the same time ingage the chooker, i can hear wind whistling, and i have to blow more to hold the piston up. Is that a way to check the piston/membrane?

That will work. Spelling is fine.