GS650G Carb Issues

[abaton6]

I pulled the tank off, and the petcock is dripping about 3 drips per second, while set at 12 o'clock. I had a hose on the vac line and when I put a slight vacuum on it, it flowed pretty good, but sometimes pretty slowly. If I set it to "prime", it flows bigtime. I pulled one of the float bowl plugs, and the bowl was full. Not sure what is going on here.

[abaton6]

I put the tank back on, fuel line and vac hose also. I saw fuel flowing when I set to prime,...no start. took the suction hose off the petcock and i could feel it sucking when the engine was turning over. I still have dry spark plugs! No fuel is being delivered. I can get it to "run" on starter fluid. Any further thoughts? I'm about ready to pull the carbs again, and ......do what? I'm not sure.

[tom203]

Make sure “choke” linkage is working correctly ....this thing needs extra dose of fuel in carb throats during cold cranking or it’s a no go!

Are you sure the choke passages are clean ? That little hole and brass tube in each fuel bowl needs to be clean in order for fuel to make it up to carb throat when “choke” lever is activated.

plus....do not apply any throttle during cold cranking or you defeat the “choke” system

[abaton6]

The choke linkage is working for sure. Can you elaborate on this? """That little hole and brass tube in each fuel bowl needs to be clean in order for fuel to make it up to carb throat when “choke” lever is activated.""" .... I'll remove the carbs again to look at this. Thanks

[tom203]

Drop a fuel bowl from carb body...note the brass tube that stays attached to carb body. This tube fits down into bowl side and picks up fuel from a “drain” hole in bottom of bowl. Very small holes, easy to get plugged up and prevent fuel from reaching choke plunger...so poke them with pin and blow them out to ensure that they’re clean

[Gorminrider]

I'm having a no fuel flow issue with MY 82 650 as well. It has a new petcock,...Ebay and a transparent fuel line with a plastic fuel filter. Wondering is the filter is too large a space to allow the vacuum to work.

I pulled the tank off, and the petcock is dripping about 3 drips per second, while set at 12 o'clock.

some of the ebay petcocks have weak springs on the diaphragm and the higher(it's merely "fuel-column" gravity) fuel pressure from a full fuel tank cause them to allow fuel past when the lack of vacuum pressure should shut them off.

Reduce fuel level in the tank to half-full or less in the fuel tank to test this. You may be able to use the spring from your original petcock to fix this. Other faults may include poor fit of the oring on the vacuum diaphragm's "plunger"

[abaton6]

I removed the carbs again,....3D time, removed the carb bowls and stuck a wire in all 4 brass tubes. They seemed fine. I removed the pilot jets to double check them. They have tiny holes on the sides, that I cleaned before, but I did not clean the hole at the bottom, ..didn't know about that one. I THINK they were clogged. I stuck a wire in those, and they are now soaking in carb cleaner. Another thing I noticed,...the choke slide,..on one carb, there is a deteriorated rubber seal. I was wondering if that would be causing any problems. The saga continues. choke.jpg

[Nessism]

I removed the carbs again,....3D time, removed the carb bowls and stuck a wire in all 4 brass tubes. They seemed fine. I removed the pilot jets to double check them. They have tiny holes on the sides, that I cleaned before, but I did not clean the hole at the bottom, ..didn't know about that one. I THINK they were clogged. I stuck a wire in those, and they are now soaking in carb cleaner. Another thing I noticed,...the choke slide,..on one carb, there is a deteriorated rubber seal. I was wondering if that would be causing any problems. The saga continues. [ATTACH=CONFIG]60809[/ATTACH]

It's always best to start your own thread on these matters instead of posting within someone else's thread. That said, did you do a full carb rebuild using the tutorial linked in my signature? No shortcuts?

[abaton6]

I didn't see that, but this was on Bikecliffs page, came highly recommenced. https://www.youtube.com/watch?v=95nlrP-yn2I&t=1130s

[abaton6]

I read your rebuild tutorial. Very thorough, but my carbs are a bit different. At the end it says the bike will run poorly, or not at all without the airbox installed. I had the airbox installed, but no air filter or filter cover. Would this affect anything? Thanks.

[Big T]

I didn't see that, but this was on Bikecliffs page, came highly recommenced. https://www.youtube.com/watch?v=95nlrP-yn2I&t=1130s

That video is not on the BikeCliff page
I watched 3 minutes of it and he has a number of errors

Nessism wrote the tutorial, and that's what's on BikeCliff

Have you read the Top 10 Newbie Mistakes yet?

[abaton6]

I read the top 10, and I've made many. I've had bikes for 52 years now, and I have never had any trouble with a carb. Never touched one. But this thing is quite vexing. I had a Norton 850 Commando that was constantly giving me grief, but never the Amal. P.S. that video link IS on bikecliffs,...that's where I found it.

[2BRacing]

I removed the carbs again,....3D time, removed the carb bowls and stuck a wire in all 4 brass tubes. They seemed fine.....

You also need to make sure that the channel in the float bowls feeding those brass tubes for the enrichener ("choke") circuit is open.

[tom203]

....At the end it says the bike will run poorly, or not at all without the airbox installed. I had the airbox installed, but no air filter or filter cover. Would this affect anything? Thanks.

The bike will start up and idle normally without filter element in.....it will start to rev up, but fall on its face soon. The CV carbs rely on slide lifting to add air and fuel ....without the air box sealed up, the slides won’t lift properly.

[abaton6]

I tried one last thing. I put the airbox cover on, and connected the hose from the top of the airbox to the valve cover. I started! It's not running great, but it is progress.