She wont run...(not without a little coaxing)

[shibby_cbs]

so heres what i got... 82 GS650G with problems running and staying running. i have removed the carbs when i picked up the bike a few days ago. i tore them apart (not completly) and cleaned out all the jets with carb cleaner...at least i think i did. reassembled them and put them back in the bike. i also removed the petcock from the tank and cleaned that out. i get everything back together and prime the carbs...and by that i mean i turn the petcock on prime for a few seconds the put it back to run...when i try and start the bike it refuses to turn over...the bike is pulling in fuel or at least i can see it going up and down in the line. i crank and crank and crank but i got nothin. just as a note i am doing all this with the airbox side of the carbs completly open...the box is completly removed. now when i spray starter fluid in the airbox side of the carbs she starts right up and idles perfect for about 3 seconds then shuts off. so what i am geting out of all of this information is there is some issue between the airbox side of the carbs and the motor side. what do you guys think?

 

[Guest]

Re-do the carbs accorcing to Basscliffs page. Do em PERFECT! Make no shortcuts. The VM carbs are very thouchy and have tp be perfect.
Replace all rubber orings in the carbs.

Replace intake orings with new provided by http://cycleorings.com/
Put the airbox on making real sure its sealed with a good clean filter.
Put new plugs in. Ya might as well buy at least 8 plugs while you're at the parts store.(NGK B8ES)
Leave the petcock on prime.
Start the bike....

Do all this and report back with your results.

 

[shibby_cbs]

ok...i ordered new intake and carb o-rings from that site a few days ago so i will have to wait for those to come in before i completly redo the carbs...the plugs are brand new and are getting excellent spark. i will put the airbox back on and see what changes when i do that...will having the carbs open on the airbox side mess with the vaccume pressure that is needed?...maybe thats part of the issue. wont leaving the petcock on prime flood the carbs?...i am probably wrong on this

 

[DanTheMan]

You have to get the bowls full of gas. Prime does that. After it starts and runs switch it to run. A clean, well sealed airbox is required to make it run properly. Do the carbs as per the carb page that BassCliff so thoughtfully made.

 

[shibby_cbs]

gotcha...ill put the airbox back on and try and start her again just to see what happens/changes and then report back

 

[Guest]

As long as you remember to turn the petcock back to run before you let the bike sit you should be ok. If it wont run with the cock on run then likely it needs replaced.
But untill you get the airbox issue resolved it wint run good, if at all.

Put the airbox back as I stated above and go from there.
Have the valves been checked?

 

[Suzuki_Don]

The VM carbs are very thouchy and have tp be perfect.

These carbs are CVs (BS), not the VM type.

 

[spwalker09]

Seconded on the valves. I cleaned out the carbs on my 450, and its still had a hard time starting. Once I did the valve adjust, it made a worlds difference in starting...

 

[shibby_cbs]

Seconded on the valves. I cleaned out the carbs on my 450, and its still had a hard time starting. Once I did the valve adjust, it made a worlds difference in starting...

the valves havnt been checked...i skimmed through that erite up but didnt really look at it...how easy hard is that job?

 

[spwalker09]

On my 450, it was as easy as taking the valve cover off, and then inserting a feeler gauge in between the cam and the tappet shim to figure out the clearance. A Haynes (or Clymer) manual will tell you what "in spec" is...IIRC its .03-.08mm. Anything below .03mm will need the shims replaced by the next size (.05mm) under. For example if you have less than .03mm (the smallest feeler I have) clearance with a 2.55mm shim, then replace it with a 2.50mm shim. There's a different procedure if you have fastener-adjusted valves (mine were shim-adjusted on my '83), which doesnt require a special tool to depress the valves to remove/insert shims like my '83.

Best to get a service manual, its clearly explained. Or maybe someone on here w/ your same vintage can steer you in the right direction

 

[BassCliff]

Hi,

From your "mega-welcome":

***********Quoted from Mr. bwringer************
Every GS850 [and most other models] has (or had) a set of well-known issues that MUST be addressed before you have a solid baseline for further troubleshooting. It's a vintage bike, and it's quite common (as in, every single GS850 I have had contact with) that there are multiple problems that have crept up and slowly gotten worse over the years. It's not like a newer vehicle, where there's generally one problem at a time.

These common issues are:

1. Intake O-rings (install NEW OEM or Viton only - common nitrile O-rings will quickly deteriorate from heat)
2. Intake Boots (install NEW -- these cannot be repaired)
3. Valve clearances (more important than most people think)
4. Carb/airbox boots
5. Airbox sealing
6. Air filter sealing
7. Petcock (install a NEW one)
8. On '79 models, install new points or Dyna electronic ignition (or at least verify that the old points are working correctly)
9. On all models, it's fairly common to have problems with the spark plug caps. These are $3 or $4 each, and often worth replacing if you're keeping the stock coils/wires.
10. Stock exhaust with NO leaks or holes -- good seals at the head and at the junctions underneath.

What I have noticed at the rallies is that very, very few 850Gs are actually running right. Make VERY sure it's actually running the way it's supposed to before busting out the modifications.

Brian's E-Z and fun plan for GS850 happiness:

1) Seal the airbox and air filter with weatherstripping.

2) Ensure no intake leaks. Spraying WD-40 or water doesn't tell you much, since very small air leaks can cause problems even though they won't suck in enough WD-40 to make a difference. Replace your intake boot o-rings and boots if needed, and seriously consider spending the lousy $28 for new airbox/carb boots.

3) Ensure clean carbs with correct settings, new o-rings, and original OEM jets. No, not just squirted with something. I mean completely disassembled.

4) Check/adjust valve clearances (Manual calls for every 4,000 miles. This is not optional.)

5) Ensure healthy electrical system.

6) Seriously consider upgrading coils and plug wires.

7) Install new, stock NGK B8-ES plugs gapped to .031".

8 ) Fine-tune float height and idle mixture screw to ensure best off-idle transition.

9) Clean air filter and reinstall with only the lightest oil mist -- over-oiling and/or letting the filter get dirty is a common and critical mistake, and will make the bike run funny at low speeds and run rich. This may take a few tries.

10) Make sure the exhaust seals are sealing.

11) Ooh, much better now, huh? You're gonna need upgraded suspension - Progressive or better fork springs and shocks. Set suspension sag appropriately.

12) Upgrade brakes with new pads and stainless lines to deal with all that extra speed.

13) Install new petcock, since I'm going to head to the roof with a rifle if I have to read about yet another #2 plug fouling and failed hillbilly attempts to rebuild the petcock and/or deny there's a problem.

14) Oh yeah -- check compression somewhere in there to ensure the valves and rings are reasonably healthy.

15) You'll probably need new OEM clutch springs -- the clutches last forever, but the springs get tired after 20 years or so under pressure. E-Z and cheap.

Carburetor maintenance:

Replace the intake boot o-rings, and possibly the intake boots. Here's the procedure:
http://bwringer.com/gs/intakeorings.html
Here's an overview of what happens with this particular problem:
http://cycleorings.com/intake.html
You'll also want to examine the boots between the carbs and the airbox. There's a good chance these are OK, but check them over.
And finally, if things still aren't exactly right, you'll want to order a set of o-rings for BS carbs from the GS owner's best friend, Robert Barr:
http://cycleorings.com
Once you receive these rare rings of delight, then you'll want to thoroughly clean and rebuild your carburetors. Here are step-by-step instructions that make this simple:
http://thegsresources.com/gs_carbrebuild.htm
-----------------------------------------------------


Once you have completed the above you WILL have a nice running, reliable motorcycle. That's all there is to it. I'm serious. If you don't do it right, it will not work. Period. You have a 30 year old motorcycle there and it needs some TLC. Keep us informed.




Thank you for your indulgence,


BassCliff

 

[Steve]

the valves havnt been checked...i skimmed through that erite up but didnt really look at it...how easy hard is that job?

Not that hard, if you know which end of a screwdriver to pound on. :-\\\

First time through, if you really take your time and also take the time to inventory your shims, allow about 2 hours. After you have done a few (dozen), you can have it down to about 45 minutes.

Read the procedure in your service manual, look at the enhancements that BassCliff has on his site, follow the suggestion at the end of my sig.

.

 

[shibby_cbs]

well i got er all back together...airbox and all with the same result. my o-rings and fasteners are due to come in tomorrow so i will get to work on the BassCliff carb tutorial....any words of wisdom BassCliff???...on another note i am having a little trouble with my petcock... its not releasing fuel when on prime until i pull off the end of the vac hose connected to the carb and suck on it like a straw...when i do that i can feel it pop open then the fuel flows...it does this both on pri and run. isnt pri supposed to flow free without the vaccume opening the valve...maybe i should look at a rebuild kit...or should i just completly dissassemble it and give er a good cleaning?

Not that hard, if you know which end of a screwdriver to pound on. :-\\\

First time through, if you really take your time and also take the time to inventory your shims, allow about 2 hours. After you have done a few (dozen), you can have it down to about 45 minutes.

Read the procedure in your service manual, look at the enhancements that BassCliff has on his site, follow the suggestion at the end of my sig.

.

Will do...thanks buddy

 

[BassCliff]

Hi,

For your petcock, see #7 and #13 above.

The carb rebuild guide is not mine. I just host a copy. Dip your carb bodies for 24 hours to be sure they are clean. Be careful removing the floats so that you don't bust a post.


Thank you for your indulgence,

BassCliff

 

[shibby_cbs]

Hi,

For your petcock, see #7 and #13 above.

The carb rebuild guide is not mine. I just host a copy. Dip your carb bodies for 24 hours to be sure they are clean. Be careful removing the floats so that you don't bust a post.


Thank you for your indulgence,

BassCliff

new petcock is on its way...boy those arnt cheap

about that...had one of the carbs apart today and noticed that it did indeed have a busted post ...whoever did it did a patch job on it and i seems to be secure but i wanted to get you guys opinion on what i should do...looked on ebay and didnt see any carbs to replace it with...maybe someone around here has one...oh and what type of solution should i be dipping them in and where to get it?

 

[Guest]

These carbs are CVs (BS), not the VM type.

Thats what I meant, sorry for the goof.
VM's are bit more forgiving from what I understand.

 

[Steve]

... on another note i am having a little trouble with my petcock... its not releasing fuel when on prime until i pull off the end of the vac hose connected to the carb and suck on it like a straw...when i do that i can feel it pop open then the fuel flows...it does this both on pri and run. isnt pri supposed to flow free without the vaccume opening the valve...maybe i should look at a rebuild kit...

Are you sure you are reading the petcock properly? :-k

Rotating the lever fully clockwise, so the lever is pointing forward is the REServe position. It will require a bit of vacuum to open it and to keep it open.

Rotating the lever so it is pointing down is the RUN position. It will also require vacuum to open it and keep it open.

Rotating the lever counter-clockwise so the lever is pointing backward is the PRIme position. On all but the '80 petcocks, it will flow gas freely without any vacuum applied. (The '80 petcocks requre a bit of vacuum to start the flow, but then will keep flowing without vacuum.)

Good luck with a petcock rebuild kit. I think the success rate with them is around 10%. You might get by with just taking it apart and giving it a thorough cleaning, then careful re-assembly. If you have a torn diaphragm in there, just get a new petcock. Yeah, it costs a bit more than a rebuild kit, but you won't have to worry about it for another 25-30 years.

.

 

[shibby_cbs]

Are you sure you are reading the petcock properly? :-k

Rotating the lever fully clockwise, so the lever is pointing forward is the REServe position. It will require a bit of vacuum to open it and to keep it open.

Rotating the lever so it is pointing down is the RUN position. It will also require vacuum to open it and keep it open.

Rotating the lever counter-clockwise so the lever is pointing backward is the PRIme position. On all but the '80 petcocks, it will flow gas freely without any vacuum applied. (The '80 petcocks requre a bit of vacuum to start the flow, but then will keep flowing without vacuum.)

Good luck with a petcock rebuild kit. I think the success rate with them is around 10%. You might get by with just taking it apart and giving it a thorough cleaning, then careful re-assembly. If you have a torn diaphragm in there, just get a new petcock. Yeah, it costs a bit more than a rebuild kit, but you won't have to worry about it for another 25-30 years.

.

yea i was deffinately reading it correctly but i went ahead and just got a brand new petcock...also got my oring kit in today and the berrymans solvent for the carb dip...time to get to work

 

[Guest]

yea i was deffinately reading it correctly but i went ahead and just got a brand new petcock...also got my oring kit in today and the berrymans solvent for the carb dip...time to get to work

Keep us posted.
Sounds like you're on the right track.

Make sure to use a good fitting screwdriver for everything, especially the jets and mixture screws. They tend to be very easy to booger up do to the soft copper they're made out of. A little thread breaker like PB Blaster helps to loosen em up.
Also be careful of the float bowl pin as those little arms are also easy to break when you punch the pin out.

 

[shibby_cbs]

alright so heres where im at...

#1: so as i said before the number 1 carb had a cracked post...whoever broke it tried to patch it up and it seemed to be alright...well as soon as i pulled the pin out it fell apart...could i just buy a blank carb body....so what are my options?

#2: all the air screws in all 4 carbs are all seized up...i got 2 of them about a half turn out then the screw heads popped so that was that...could i just drill them out and buy new ones...what are my options here?