GS 850 will not stay running

[Guest]

Hello sirs I am new to this forum and need some GS advice. I recently purchased a group of three 850s in different stages of take apart. Here lies the problem I need help with.
What I will say first off is the carbs are open(no air box nor air filters) those parts are gone.
Carbs have been ultrasonically cleaned and the bowls are full of fuel.
The machine will fire only with a splash of gas or Gods Breath but will not stay running even with choke fully pulled

I hope I have given enough for someone to say hey stupid try this

Thanks in advance

[JTGS850GL]

Are you using the choke?

Explain a little about the rebuild process of the carbs. What was replaced and what was not. Have you adjusted the valves?

It should be able to start with the airbox off but will not run much beyond a quick rev. The CV carbs are pretty touchy about having the proper restriction on the airbox side.

[chuck hahn]

Take a single layer of Tshirt rag and zip tie some over the intakes of each carb and see what happens. Some restriction is required for carbs to work. And just HOW wree the carbs cleaned? tell us every detail of what you did to them..skipping nothing.

And heres the place for all things Suzuki.Note that on the left under the main manual menu boadr there are carb rebuild tutorials...choose the CV one.

http://members.dslextreme.com/users/bikecliff/

Next, get the oring kit here and also measure the intake manifold orings INSIDE diameer and replace them. See page 3 of the oring site for size sellections. 1 kit does all the carbs and fuel tubes.

http://cycleorings.com/

Get the manual form Bikecliffs and do the valves per themanuals exact instructions. Everything works in concert so all the maintenance needs to be done for setting a baseline to get down to brass tacks.

[mjpcarbon]

The bowls were pulled as well as the diaphragms then double cycled in the Ultrasonic cleaner by myself. Blew and checked all the passages
I tried the t shirt test and the bike will only run for about 5-10 seconds if I wet the shirt with fuel.

As for hookup since I didnt take them apart I hooked the right side carb line to the petcock and the other carb vac line to the fuel sender drip barb

Again all the bowls have fuel in them but really feel like I am missing the obvious that it will not stay lit for more than a few seconds unle

[Nessism]

Carb rebuild tutorial linked in my signature. You may want to go through it and compare against the ultrasonic cleaning job you did. Pay attention to the carb passage verification tests and making sure the jets are clear.

[mjpcarbon]

I will follow the link you have posted, just find it odd that all four would have issue.
I would have thought there would be some life, feel like I am missing something

[2BRacing]

As for hookup since I didnt take them apart I hooked the right side carb line to the petcock and the other carb vac line to the fuel sender drip barb.

You have not connected the vacuum hose to the correct place.

The fuel line (larger diameter pipe of the two) connects to the larger nipple on the petcock. The smaller tube (vacuum tube to activate petcock when engine is running, to allow fuel to flow) should be connected to the nipple on number 2 carb (counting number 1 from the left hand side as you sit on the bike).

The fuel sender drip barb should be connected to a long tube going down at the back of the engine.

[JTGS850GL]

Did you do a proper bench sync? Did you measure float height and level?

Carbs should be disassembled COMPLETELY in order to do a proper cleaning. All of the internal O-rings MUST be replaced. The pilot screw plug must be removed and the all components below that removed as well in order to clean the pilot system.

Follow the rebuild tutorial to the letter and you wont have a problem. Do a half baked job and you get less then ideal results.

[mjpcarbon]

ok will do , and I will order up the o rings. I do have a question though since there isnt an airbox at all how would I go about restricting the airflow or is that hit or miss

[mjpcarbon]

2Bracing what about the two hose that come off between carb 1-2 and 3-4 ?

[2BRacing]

2Bracing what about the two hose that come off between carb 1-2 and 3-4 ?

Those are vent hoses. When an airbox is fitted, those hoses go over the top of the airbox and down behind the airbox.

Look here http://members.dslextreme.com/users/...locations.html for a more complete picture. Are your carbs like the ones in the photos (CV type) or the older VM type?

[JTGS850GL]

With no airbox at all it will idle but will not run much above that. If you plan on running without the stock air filter then be prepaired to purchase some quality pod filters (K&N or APE) and pickup up the Dyno-Jet kit. If not then it will be a LONG drawn out exercise in tuning it properly. Yes, it has been done without the kit and cheap pods but MUCH more hit and miss on the jetting.

The hoses that come of between the 1-2 and 3-4 carbs are vent lines. They normally run from the carbs to area behind the airbox. Just route them up and over to area behind the engine near and below the battery box.

[mjpcarbon]

Wonderful info cant wait to get going on this
Thanks so much

[2BRacing]

Look here for all the information you need: http://members.dslextreme.com/users/bikecliff/ including the OEM service manual for your bike.

Operation of the 3 different petcock positions is explained in the file "Petcock Rebuild" linked on the right hand of BassCiff's page.

[Steve]

Apparently, you only dropped the float bowls and took the diaphragms out before "cleaning" the carbs?

Your next step has been suggested a few times here already, you need to PROPERLY clean the carbs.
Follow the guide that is in Nessism's signature, that is the BEST guide for cleaning the carbs.

Note that the process will take several days, as you will be soaking each carb body in the "dip" for a full 24 hours. While you are waiting, check your valve clearances. These valves tighten up with use, and too-tight valves will prevent cold starting.

Do yourself and your bike a favor, THROW AWAY THE STARTER FLUID.

As a last resort, if you don't feel comfortable taking your carbs apart into about 300 separate pieces, chef1366 and I both offer carb cleaning/rebuilding services, which you can find advertised in the "GS Parts and Services" forum.

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