Need help with gs 850 fuel system

[Machinegunner]

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-digital-caliper-with-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.

[Machinegunner]

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

[Machinegunner]

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?

[Machinegunner]

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 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.

[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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[Steve]

Even after running for just a few seconds the exhaust pipe will have sufficient heat to cause 1st degree burns.

That also depends on whether you have stock or aftermarket pipes.

Stock pipes are double-walled, which takes a bit longer before they get warm enough to burn you. Aftermarket pipes are single-walled, so yes, they will burn you much quicker.

If we want to subscribe to the nanny theory, we would certainly not advocate doing anything as dangerous as trying to touch an exhaust system. In fact, we would probably not even advocate riding a motorcycle. However, most of us have an IQ of sufficient level that allows us to stand vertically and breathe at the same time. I think most of us would not GRAB the pipes, but touch them ever so briefly. Yes, it's a bit of an acquired technique, but right after startup, there is very little chance of bodily damage.

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[Machinegunner]

Yeah an ice cube would be easy. Burned my leg slightly on the pipe but not bad. It does bog down when I give it gas but then revs up making it dangerous for a newish rider(me) there is no in between. I will check the cylinders.

[Boriqua]

Yeah an ice cube would be easy. Burned my leg slightly on the pipe but not bad. It does bog down when I give it gas but then revs up making it dangerous for a newish rider(me) there is no in between. I will check the cylinders.

Oh no!! The dreaded "Chase the air leak" I think. If it bogs and then you give it a bit of twist and she revs high and wont come down ?may? indicate an air leak.

So like I suggested about the gas applies here again. Go to the furthest point of air .. your air filter box and systematically going forward to the engine check every connection and every bit of rubber. For me getting the airbox and carbs lined up well enough to hold air before I got new boots was a bear.

Have you tried to take it out yet? The very very first time I got my bike started it did the same thing. I took it for a short trip and it settled in. I still had 4 months of hunting and peaking to get everything right but perhaps after its first cleaning and having sat things were stiff. You will likely have more work to do but depending on how high she is revving you should give it a spin even if it means modulating the clutch a bunch so you can get a better indication of where she stands.

[Machinegunner]

It’s probably the boots between the air box and carbs. I had a heck of a time getting them on and they might not be properly fitted. I’ve ridden it about a quarter mile ( up and down the driveway )

[Machinegunner]

So I started it up and rode it a little to warm it up so I could test for a dead cylinder. After a few minutes it stopped sounding bad and the next thing I know my leg is soaked with gas. Carb 3 was leaking. I assume that the gasket is bad and the float was stuck so as soon as it broke free it leaked gas? I ordered another gasket and took the carburetor off a third time. 😑 also looked at the air box and there was a mouse nest so I cleaned that out. It must have been running rich because on checking the spark plugs again they were black. So hopefully I found everything. Once I get it going good I will need help on the charging system. The previous owner had told me it wasn’t working. I’ll ask about that in the correct forum.