Trouble Starting

[Soyanarchisto]

Bear with me. I'm a total noob when it comes to wrenching.

I bought my 82 GS450E from someone who said that he had completely rebuilt and cleaned the carbs. He said he had it running and then just let it sit. When I bought it from him, he said it just needed a battery.

Bought a new battery. I noticed a small amount of surface rust in the tank so I cleaned and sealed it. Reinstalled the petcock and tried to fire it up. Engine turns over but doesn't fire. Sounds like its not getting any fuel.

Disconnected the tank and turned the petcock from run to reserve. Nothing comes out. Remove petcock, disassemble and clean, reinstall. Nothing comes out. Order a new petcock from ebay and the orientation of the fuel and vacuum ports are towards the rear of the bike, making it impossible to connect the lines. I'm pretty certain this is not the right petcock (see photo below).

Reinstall the original petcock, turn it on reserve and suck on the fuel port. Nada. Blow on it and I can hear air bubbling in the tank. Suck again and get a mouthful of gas. Yum. Twist to run and nothing. Reinstall on bike and twist to reserve, a little gas dribbles out the tube so I connect it. Try to start the engine and it acts like it got a little fuel then just grinds over as if its not getting fuel again. I've tried this exercise with choke on and off, with throttle open and close. Same results no matter what.

I'm starting to lose even more of my hair and I cant afford to lose anymore.

My first concern is whether I even had the correct petcock to begin with. The one on the bike only has two settings: straight down and 'res' which is pointed to the front of the bike. There is no 'pri' setting. There is a brass screw to the right of the straight down position that prevents the cock from being turned in that direction. Near as I can tell from searching this site and BikeCliff's site (AWESOME resources and thank you very much), my petcock is not original.

Secondly, is there a way of checking to see if the carbs are even getting fuel? Am I going to have to tear out the carbs?

HELP!!

[Steve]

I bought my 82 GS450E from someone who said that he had completely rebuilt and cleaned the carbs.
He said he had it running and then just let it sit. When I bought it from him, he said it just needed a battery.

And you believed him?

My first concern is whether I even had the correct petcock to begin with. The one on the bike only has two settings: straight down and 'res' which is pointed to the front of the bike. There is no 'pri' setting.

I have no personal experience with that style petcock, but I think I remember someone saying that the brass screw is your PRI control.

.

[MisterCinders]

If the petcock has two lines, it must be vacuum operated. Usually PRI is the opposing position to RES. See if that opens up the flow, even though it is not marked. Does the lever turn the other direction?

[NeyborDayfid]

Does your petcock have a line running to the rear of it? Or, does it have a nipple on the rear or side of it that looks like you could put a hose onto? If it does then it needs a pressure feedback from the carbs to pull a diaphragm back and let fuel flow.
Also, I'm looking at the boots on your airbox where they attach to the rear of the carb and they appear to have been cut.
Are they? If so, you wont have the correct resistance through the air-filter.
You'll need to seal it.
Hope that helps.

[BassCliff]

Hi,

There are a couple of maintenance lists in the "mega-welcome" which you received in THIS THREAD. How many maintenance tasks have you completed? Skipping steps or taking shortcuts will lead to much frustration and catastrophic failures.


Thank you for your indulgence,

BassCliff

[wally]

I think it should have 2 nipples - 1 for fuel and the other vacuum.

My 450 has the same petcock - either on or nothing.

Good luck!

[Soyanarchisto]

And you believed him?


I have no personal experience with that style petcock, but I think I remember someone saying that the brass screw is your PRI control.

.

I have no reason not to believe him. He got the bike when an acquaintance asked him to get it running. He said he did so and when the acquaintance balked at paying him, he signed over the title instead.

[Soyanarchisto]

If the petcock has two lines, it must be vacuum operated. Usually PRI is the opposing position to RES. See if that opens up the flow, even though it is not marked. Does the lever turn the other direction?

It does not turn in the other direction; its either straight down or pointed to reserve.

[Soyanarchisto]

Does your petcock have a line running to the rear of it? Or, does it have a nipple on the rear or side of it that looks like you could put a hose onto? If it does then it needs a pressure feedback from the carbs to pull a diaphragm back and let fuel flow.
Also, I'm looking at the boots on your airbox where they attach to the rear of the carb and they appear to have been cut.
Are they? If so, you wont have the correct resistance through the air-filter.
You'll need to seal it.
Hope that helps.

It has a vacuum port and its connected. Whether the boots to the airbox were cut or not, I do not know. I'm planning to eventually eliminate the airbox and mount K&N pods. First, I want to get it running.

Thanks!

[GateKeeper]

It has a vacuum port and its connected. Whether the boots to the airbox were cut or not, I do not know. I'm planning to eventually eliminate the airbox and mount K&N pods. First, I want to get it running.

Thanks!

do that as you say......

Then get pods, as those will give you even more grief, unless you are really good working on carbs/jetting, shimming and so on.....

your petcock is vacuum operated and seems to be working, since no fuel is coming out while in the ON position, this is how it should be...

however if in Prime, gas should flow, with out hesitation......

now to get fuel flowing you need vacuum, as a test attach a longer hose to the vacuum part and using you, suck in on that hose, you should see fuel coming out of the fuel line (have it disconnected so you can see this)

if this works then your petcock is operational, and time to move on and find other reasons the bike won't start

.

[Soyanarchisto]

Excellent! Thanks for the advice.

[GateKeeper]

My mistake....I made a booboo

if in Prime gas should flow freely.........it does not require vacuum at this time....

designed this way to allow you to get he carbs filled up quick if bike has been siting for a long time.....

Sorry....

[MisterCinders]

If I understand you correctly, you have a vacuum operated petcock that doesn't have a PRI setting. Not sure how you are supposed to fill the bowls with that device.

If you are not getting fuel after re-intstalling the carbs, I suspect that you have a chicken-and-egg problem. The bowls have no fuel to power the vacuum to pull more fuel to fill the bowls (hence the need for a PRI setting).

To fill the bowls without a PRI setting, try disconnecting the vacuum line from the carb and sucking through it like a straw No gas should come through the vacuum line, but only a little suction should trigger the fuel flow. Do that for about 30 seconds to fill the bowls, then reconnect the vacuum line to the carbs. That should at least break the chicken/egg dilemma.

Where did you get this oddball petcock? Did Suzuki make such a creature?

[MisterCinders]

And you believed him?



I have no personal experience with that style petcock, but I think I remember someone saying that the brass screw is your PRI control.

.

Just noticed this. You should try turning that screw to activate PRI and fill the bowls. Then you don't have to suck (on the vacuum line, at least ).

[Soyanarchisto]

I'll give this a try as soon as I get off work. Thanks