Need help with gs 850 fuel system

[Guest]

mg,

Other conversation:

Is it running okay (now that you figured out the petcock)?
If not: Please describe "cleaned the carburators"....

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Haven?t received the petcock yet. Mine is the 50 mm. I tried putting gas via a funnel straight into the gas line but the battery died after about 10 seconds so I didn?t get it started. I checked for pressure on vacuum line and it was fine. I will update as soon as I receive the petcock.

By cleaning the carbs I mean complete disassembly, soaked in carb cleaner and jets checked for clogging.

 

[Guest]

Glad you went with a new petcock. I have the same model and had the same problems. I tried rebuilding the origianl and then went with a second hand unit and only got it right when I bought a new (50mm) part. Since then all has been good.

 

[Guest]

Put the petcock in today. Found out the choke cable is broken . Engine won?t start or run unless I hold the choke bar( not sure what it?s called) all the way to the left. Even then it runs very slow. Where is the carburetor (fuel or air) adjustment?

 

[Steve]

Engine won’t start or run unless I hold the choke bar( not sure what it’s called) all the way to the left. Even then it runs very slow. Where is the carburetor (fuel or air) adjustment?

It is quite normal to need the "choke" (it's actually an "enrichment system") to start the engine, especially when cold. To answer your question, I am going to refer to your first post and ask a question. :-k

Hey, newbie here. Had a 1980 GS850L given to me. It had been sitting for 4 years. I cleaned the carburetors, ...

Exactly HOW did you "clean the carburetors? :-k If you had cleaned them properly, you would know where the adjustment is for Idle speed, because it would have been removed in the process of cleaning the carbs.
But, to answer your question, the IDLE SPEED control is below the carbs, between #2 and #3.

If all you did was to drop the float bowls and clean them out, your bike will not run (well) until you clean the properly.

Click HERE to visit our library, also known as "BassCliff's site." You can download a manual for your bike and see tutorials for virtually anything you need to do to your bike.

Click HERE to see the tutorial for properly cleaning your carbs.

You may as well continue with some other maintenance that has likely been ignored, so click HERE for a tutorial on how to adjust your valves.

You will eventually need to check your charging system, too, but let's get the bike running first.

If the bike has been sitting for four years, I can probably guarantee that the tires and brakes were not changed just before the bike was parked, so they should be checked, too.

Yes, the list goes on and on, but when you are done, you will have a safe, reliable bike.

.

 

[Guest]

Wasn't asking for the idle adjustment. Is the single screw on the bottom of the float bowl the fuel adjustment? If so what is the factory setting?(how many turns out?) I might have tightened them all of the way when reassembling the carbs:uncomfortableness:. I will post a video of it running as soon as I figure out how. Only runs with choke all the way out and if I rev it at all it cuts off.

 

[Guest]

 

[Steve]

Wasn't asking for the idle adjustment. Is the single screw on the bottom of the float bowl the fuel adjustment? If so what is the factory setting?(how many turns out?) I might have tightened them all of the way when reassembling the carbs:uncomfortableness:. I will post a video of it running as soon as I figure out how. Only runs with choke all the way out and if I rev it at all it cuts off.

OK, if you are not asking about the idle adjustment, the only other external adjustment is for pilot mixture. That is NOT the "single screw on the bottom of the float bowl", that is the drain screw that will empty the gas out of the bowl. They SHOULD be reasonably snug so they don't fall out.

The pilot adjustment (also known as the "mixture screw") is on the top of the outlet of the carb. If your carbs have never been worked on (quite likely), they are still sealed from the factory and not recognizable as such. If you do have access to the screws, turn them IN slowly, counting turns until they seat LIGHTLY, record the numbers. When I rebuild a set of carbs, I start with the screws out three full turns, knowing that they will need to be fine-tuned from there. They might end up about 2 to 2 1/2 turns out, but three turns provides a slightly richer mixture that lets it start easier for tuning.

Again, I have to ask, exactly how did you "clean the carbs"?

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[Guest]

OK, if you are not asking about the idle adjustment, the only other external adjustment is for pilot mixture. That is NOT the "single screw on the bottom of the float bowl", that is the drain screw that will empty the gas out of the bowl. They SHOULD be reasonably snug so they don't fall out.

The pilot adjustment (also known as the "mixture screw") is on the top of the outlet of the carb. If your carbs have never been worked on (quite likely), they are still sealed from the factory and not recognizable as such. If you do have access to the screws, turn them IN slowly, counting turns until they seat LIGHTLY, record the numbers. When I rebuild a set of carbs, I start with the screws out three full turns, knowing that they will need to be fine-tuned from there. They might end up about 2 to 2 1/2 turns out, but three turns provides a slightly richer mixture that lets it start easier for tuning.

Again, I have to ask, exactly how did you "clean the carbs"?

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Took off float bowls and top took out jets and soaked. Drained the carbs last night and carbs 3 and 4 had no gas in them?

 

[Boriqua]

You mean when you initially took them off to clean the bowls had no gas? There is only two things I can think of.

one ..gas is not coming in because of a physical blockage where the fuel enters the carb. The gas line and the hole that allows gas into the carbs are fairly large but if there was a lot of rust in the tank .. I guess its possible to block it.

Second thought is there is no gas going in because of a mechanical failure. Your floats sit on a wee bitty pin that controls fuel flow. There is a name for it that escapes me now but if they are stuck in the closed position as if the float were at their maximum height just due to gunk and age then no gas. It works kind of like the float in your toilet to control how much gas lives in the bowl.

Edited to add
Soaking alone will NOT clean your carbs. Download one of the pdf's on cleaning. Dont ask me how I know
I Soaked, then sprayed all the passages with carb cleaner, The washed them in warm water with dish soap and then blew them out with a compressor.
Oh .. but I did not poke! So a few weeks later I was doing the whole damn thing again .. so poking is good.

 

[Nessism]

Carb rebuild tutorial linked in my signature. Might want to review again. Some of the questions being asked suggest that some steps were missed. Also check the newbie mistakes thread to see if anything applies. For example, it's critical to change the intake boot O-rings if you haven't already.

Again, the factory service manual details how the prime feature works with the leverless petcock. If no fuel is getting through to carb 3 and 4 that means that your float needles are stuck or you are not engaging the prime to fill the bowls.

 

[Guest]

guess im going to take the carbs off again. its a pain in the butt to put back on. took me over an hour.

 

[Boriqua]

guess im going to take the carbs off again. its a pain in the butt to put back on. took me over an hour.

Look at the bright side .. the more you do it the easier it will be ....

Bwhahahaha ... no ... Im lying .. its still going to be a pain in the arse! I just did boots a couple weeks back and yup .. taking them out sucks but it does get faster.

The float needles will come right out when you remove the float pins but the housing the float needles live in has a screen and you should pull that whole piece out when you soak the carbs. That housing can be a pain to get out so try not to score it to much when removing. Its fitted in with a tight fitting rubber gasket. I wrapped my channel lock jaws with electric tape before I went at the brass.

Check to make sure the float needles still work. Its a tiny spring loaded piece. Do yourself a favor and check float heights when you reassemble. I tried three auto places as well as lowes and home depot before I found this caliper at harbor freight.

https://www.harborfreight.com/6-in-...sae-and-metric-fractional-readings-68304.html

You need the measuring rod that comes from the bottom for this gig and while calipers are a plenty the one with that rod were not available.

 

[Guest]

Got the carburetor le back on. Still need the choke on for it to run but it is much better. On the mixture screws, do they add more air or gas? I have them 3 turns out but it sounds lean.

 

[Boriqua]

You will usually need choke to get started. It been getting down to the 50's at night .. chilly and I will need little less than half choke to get started and partial choke for about the first mile then in idles along perfectly. If you have the one screw adjustment at the top of the carbs then Counter clock wise makes it richer, clock wise leaner
alex

 

[Guest]

You will usually need choke to get started. It been getting down to the 50's at night .. chilly and I will need little less than half choke to get started and partial choke for about the first mile then in idles along perfectly. If you have the one screw adjustment at the top of the carbs then Counter clock wise makes it richer, clock wise leaner
alex

Got it running. Starts easy and idles well but when I go throttle it it hesitates almost like there is a cylinder not firing. I checked all the spark plugs, all of which were in good condition and I have gas getting to the cylinders. Any ideas?

 

[Boriqua]

I always repeat in my head ... Its not magic... It needs gas, air and a spark. So now that you have gas check air. Is your filter foam or paper. If its foam it may need cleaning and if its paper it may need replacement.
The i would check to make sure i have spark at all cylinders. For $3 i bought a tester from harbor freight. You plug one end in the spark plug cable and the other to the spark plug. If the coils are all firing you will see a light on all the cables when you have attached the tester. You can also ground the plugs one at a time which may be better because then you are testing spark at the plug itself. When I brought mine to life I had a bad coil which would come in and out.
Im a newbie as well so you may get better answers but its just spark, air and gas so I started at tge gas tank and just kept going forward.

 

[hannibal]

When you first start the bike, touch the headers at each cylinder. If one stays cold, that cylinder is "dead". Could be caused by too little or too much fuel, no spark, or no air.

If all cylinders are getting hot, then I would check float heights. Have you checked valve clearances? Have you benched synced and vacuum synced the carbs?

 

[Guest]

When you first start the bike, touch the headers at each cylinder. If one stays cold, that cylinder is "dead". Could be caused by too little or too much fuel, no spark, or no air.

If all cylinders are getting hot, then I would check float heights. Have you checked valve clearances? Have you benched synced and vacuum synced the carbs?

Checked all of the spark plugs. They are good. Didn?t think to check for heat. I bench synced the carburetors but this is my first time doing that so I might not have gotten them 100%right.

 

[jdvorchak]

Ignition of the fuel in the cylinders produces temperatures of 700?C[FONT=arial, sans-serif] or more. That is about 1300 F. Touching an exhaust pipe, especially near the head, is not a great idea. Safe way is to spritz water or even touch the pipe with an ice cube. Even after running for just a few seconds the exhaust pipe will have sufficient heat to cause 1st degree burns. When you gain experience you'll be able to hear an engine running on all cylinders and tell the difference when it's not running on all. Usually the first hint is that it will bog or hesitate when you twist the throttle. Also will not seem to scream to redline. [/FONT]

 

[Redman]

Boiler operator showed me to use the back of fingers between knuckles, wiggle fingers moving back and forth, to check temperature of things. Shin is thinner there so can feel quicker, and with wiggling finger can quickly retract fingers if getting too hot.
If use finger tips, where skin is thinker, by the time the heat soaks into were the nerves are, it is too late, and then have to move entire hand and arm.

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