Carb Vacuum/fueling issues

[TPELL603]

I recently got a free 86 GS450L.

Stock everything besides cone air filters.

Jeta are 47.5 and 115 I believe.

The good?
i got a free bike

The bad?
its been sitting for more then 5 years.
it had no battery
the key was broken off in the ignition
the carburetor was removed and sitting in a box.

I made a new key.
Installed a new battery.
Gave the Carbs a good cleaning.
Cleaned the gas tank and installed a manual gas valve along with fuel filter.

Im having a hard time getting to start. I?ve got air and work and my carburetor bowls have fuel in them but it will not run. It will run on ether but that?s it. I?ve bypassed the petcock and plugged the vacuum lines and it still doesn?t work.

I can find the fuel and vacuum line diagrams anywhere online.

I have my main fuel Line coming from petcock on tank down to the t on the carbs.
My vacuum lines coming off the carbs near the engine side that go into a t then into the petcock.

It looks like there?s two holes on the carbs that look like they should have hoses on them but I don?t know what they do.

I also have a small rubber hose on the engine side of the carbs that I can?t find out where it goes.

Ive attached picture but I can?t figure out how to do more then 1

any help is appreciated.

 

[TPELL603]

This is another tap that I?m not sure if anything hooks up to. There on in each carb

 

[Steve]

To get it to run, you will need to CLEAN the carbs and probably check valve clearances.

Please describe what you did to perform a "good cleaning".

.

 

[TPELL603]

To get it to run, you will need to CLEAN the carbs and probably check valve clearances.

Please describe what you did to perform a "good cleaning".

.

i disassembled the carbs and put them in parts cleaner.
Blew out all passages with an air hose. Replaced necessary gasket and orings.

Im also curious how the choke works. It just pulls a rod on the carbs what does that allow it to do. It?s not opening the butterfly valves so I?m curios.


How do I check valve clearances?

Thanks
tommy

 

[Rijko]

others here know the GS450L better, but this seems strange to me :

My vacuum lines coming off the carbs near the engine side that go into a t then into the petcock.

Usually there is just 1 vacuum line to open the petcock.

 

[TPELL603]

I would assume so because there is one fuel line that goes into a T in between the carbs. But when i got the carbs both vacuum lines were already T'd together going into one pipe so i figured this to be the proper configuration. Right now im bypassing the petcock until i can get a hold of a vacuum pump tester to test it. My sole goal is to just get her running.

 

[tom203]

The "choke" is actually an enricher...not a plate across the carbs throat. The rod opens a port internally on each carb and supplies a bonus dose of fuel/air into carb throat . Do not use any throttle if you want "choke" to function - it relies on closed throttle plate for vacuum strength.

 

[TPELL603]

Interesting. Thanks for the info. I pulled the carbs back off last night and noticed that the rod didn't move all that much. I pulled it apart and it was pretty stiff and not functioning. I cleaned up the rods/plungers and got them to move freely. I guess ill give it another go tonight to see if it starts. I just put new plugs and wires in it and last night when i was trying to get it started with the choke on it wasnt firing. I pulled the plugs and they had no gas on them at all. So its possible choke assembly wasn't allowing gas in at all. Guess well find out tonight.

 

[Nessism]

You might want to check this thread since it has tons of info for new bike owners...https://www.thegsresources.com/_forum/showthread.php?196338-New-Members-CLICK-HERE!!

Also, read though the Newbie Mistakes thread linked in my signature to see if anything applies. Just off the top of my head it seems clear that you did not properly clean the carbs. Basscliff has a 450 carb rebuild tutorial and the tutorial as linked in my signature also has appropriate info that you may find helpful. For example, making sure the choke pick-up tube is open as well as the choke passage in the float bowl.

Good luck

 

[TPELL603]

That carb rebuild tutorial is awesome. Ill strip them back down tonigh

 

[Gorminrider]

I also have a small rubber hose on the engine side of the carbs that I can’t find out where it goes

picture is small but that is the vacuum line that attaches to petcock from what I can see of your arrows and description.

the other picture- no hoses on those....those are to let air out as fuel displaces air in the bowl and would serve as overflow too except it usually runs out of jets first..

 

[TPELL603]

Im not sure this is the vent for the petcock. Its too small. it appears to be attached to something at some point. Maybe the intake box. This bike never came with the intake box so im not sure where certain lines are going.

 

[Gorminrider]

There are no lines from the carbs to the airbox.The petcock's vacuum hose is not as large as the fuel line. This vacuum line is attached to a nipple on the intake throat of the right hand carburettor on these 450s. If your petcock is not functioning, plug this vacuum line.

 

[TPELL603]

There are no lines from the carbs to the airbox.The petcock's vacuum hose is not as large as the fuel line. This vacuum line is attached to a nipple on the intake throat of the right hand carburettor on these 450s. If your petcock is not functioning, plug this vacuum line.

ok sounds good. Glad I finally got some clarity on this. There?s still two 1/4? lines that were on the carbs when I got them. On on each carburetor on the sides towards the front. Any idea where those are suppose to go

 

[Nessism]

Your photo is too small to see clearly. Putting photos on flickr or similar and linking the IMG code is a good way to get your photos to show up here in high definition.

Most likely that port is a float bowl vent line. You can verify that by tracing the port and figuring out where it's routing.

 

[Steve]

There’s still two 1/4” lines that were on the carbs when I got them. Any idea where those are suppose to go

Ideally, all lines should be metric, so those 1/4" lines need to go in the trash bin.

Unfortunately, most hoses that you will find in the auto parts stores are thick-walled, reinforced hoses that will withstand the pressures in a fuel injection system. That makes them bulky and non-flexible, which is the main reason that I avoid them. Yeah, the proper stuff costs a bit more, but don't let the price scare you off too much. The fuel line is about $12 or so, but you get about 6 feet of it for that price, not just the few inches that it takes for your bike.

Fuel line is 7mm, which is in between 1/4" and 5/16", and the proper hose works SO much better.

In post #11 you appear to be pointing to the vaccum line that goes to the petcock. That is 4.5mm hose. If you don't want to splurge for the proper stuff, 3/16" hose is pretty close.

.

 

[TPELL603]

Still working issues out. Had the carburetors off and cleaning them up and one of the studs broke for the float bowl mount. I ended up picking carbs off an 81 GS450L that ive taken apart and started cleaning. Ive got K&N PODS 48MM and EMGO mufflers on it so once i get these carburetors back on ill start the whole jetting process

 

[LAB3]

On my bone stock 450t those two lines are the float bowl overflow tubes, they route up over the carbs and sit on top of the airbox. Can't imagine an L model being that much different.

 

[TPELL603]

Getting there

Getting there

On my bone stock 450t those two lines are the float bowl overflow tubes, they route up over the carbs and sit on top of the airbox. Can't imagine an L model being that much different.

Yup i finally figured out where everything goes as far as the fuel and vent lines go. I ended up tracing everything out on a similiar year GS450

Ive got the carbs clean and apart on a bench and i want to get a good base set of jets in there for my set up 48MM Pods and emgo free flow exhaust. Then i can start tuning them in.

Does anyone know anything about the dyno jets kits for these? The website only shows a jet kit for an 83 GS450.

Ive been doing alot of research on jetting for pods and a slip on emgo exhaust and multiple people have multiple opinions on it.

Just trying to nail down a solid plan for when i get these carbs back on.

 

[Steve]

On my bone stock 450t those two lines are the float bowl overflow tubes, they route up over the carbs and sit on top of the airbox. Can't imagine an L model being that much different.

You might want to re-examine your thinking there. :-k
If they are "overflow" tubes, why don't they go DOWN, so they can drain any overflow?

Does anyone know anything about the dyno jets kits for these? The website only shows a jet kit for an 83 GS450.

I don't remember if the change was in '82 or '83, but the newer 450s had different carbs than the earlier ones. Since you are starting with '86 carbs, the '83 jet kit should work just fine.

.