82' CB650 Carb not pulling fuel

If it's broken or just needs tweaked

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imandrewparks
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82' CB650 Carb not pulling fuel

Postby imandrewparks » Sat Feb 20, 2016 9:16 am

Hey everyone! I have a couple questions for you. I recently picked up a 1982 CB650 standard that I'm trying to get running. When I bought it the guy had it hooked up to a battery charger to start it, saying it needed a new battery. He mentioned there was rust in the tank, so he had just poured gas into the bowls to get it to start for me to prevent gunking the carbs. It started, stumbled, then cut off.
I got it home, rebuilt the carbs, changed the oil, etc. my tank is currently ripped apart at my friends house(different story,) so I just used the tank from my XR650 to see if it would start.
What would prevent fuel from getting to my carbs? Petcock on, fuel in the line, but not entering the carb. Almost like there's a vacuum or something. I even tried detaching the fuel line, and then it immediately poured out of the fuel line once disconnected from the carb. Do you think there could be a blockage where it enters the carb? I rebuilt them but that was something I didn't even think about cleaning. I even attached a small length of tubing to the carb and tried pouring it directly into that small tube from a funnel and it still wouldn't accept it.
Any suggestions would be greatly appreciated! Can't wait to get her up and running!

cb650
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Re: 82' CB650 Carb not pulling fuel

Postby cb650 » Sat Feb 20, 2016 4:55 pm

There is a auto shut off that is vacum controlled. If it is there remove it and just get in habit of turning off fuel manually.
There are threads on it here and on sohc4
Did you clean the tank out?!?!?!?!

imandrewparks
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Re: 82' CB650 Carb not pulling fuel

Postby imandrewparks » Sat Feb 20, 2016 5:49 pm

Thank you so much!

cb650
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Re: 82' CB650 Carb not pulling fuel

Postby cb650 » Sun Feb 21, 2016 5:53 am

Be sure to plug the vacuum port
Did you clean the tank out?!?!?!?!

imandrewparks
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Re: 82' CB650 Carb not pulling fuel

Postby imandrewparks » Sun Feb 21, 2016 4:39 pm

So I hate to be a pain in the rear, but where exactly is the vacuum port? Would that be the top nozzle where the fuel line originally meets the auto fuel valve? This is my first bike with an AFV so excuse my ignorance!

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Folsoml
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Re: 82' CB650 Carb not pulling fuel

Postby Folsoml » Sun Feb 21, 2016 5:25 pm

Take a look at the diagram at this link:

http://www.partzilla.com/parts/search/H ... parts.html

It will show you how it should be hooked up. The easiest thing to do is remove the auto fuel valve all together. Run the fuel line straight from the petcock to fuel inlet tube. Just remember to turn the petcock off when you park it.
Have a problem with your CB650? Have a technical question? Click here!


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Volker_P
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Re: 82' CB650 Carb not pulling fuel

Postby Volker_P » Tue Feb 23, 2016 4:36 am

Welcome here! :D

Guess everything to the vacuum shutoff is clarified.
Just wanted to say that I also had a CB650 together with an XR650(L). I liked this interesting combination from completely different worlds.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

imandrewparks
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Re: 82' CB650 Carb not pulling fuel

Postby imandrewparks » Sun Feb 28, 2016 5:58 pm

Thanks so much for the help guys! I absolutely love having a CB650 and an XR650L. Best of both worlds!

cb650
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Re: 82' CB650 Carb not pulling fuel

Postby cb650 » Sun Feb 28, 2016 6:20 pm

I had the opportunity to ride a xr once. What a monster!!!!!
Did you clean the tank out?!?!?!?!

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Volker_P
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Re: 82' CB650 Carb not pulling fuel

Postby Volker_P » Wed Mar 02, 2016 2:48 am

I'd say the XRL just rides like a bicycle but with "some" more power. :lol:
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

imandrewparks
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Joined: Thu Feb 11, 2016 11:48 am

Re: 82' CB650 Carb not pulling fuel

Postby imandrewparks » Sun Mar 20, 2016 11:03 am

Hey guys, so I'm finally getting around to messing with the carbs today. Just to be clear, according to the diagram shown above, please correct me if I'm wrong. I should be
1.) Removing the AFV from the carb rack
2.) Run fuel line from petcock to where lines 3 (or 7?) was leading to into the carb
3.) Plug line number 4

That should be it, right? Thanks for the help this far guys, I appreciate it!

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Volker_P
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Re: 82' CB650 Carb not pulling fuel

Postby Volker_P » Tue Mar 22, 2016 2:05 am

Right.
If available, I would replace the nipple for line 4 in carb #2 by a screw.
I also would consider to insert a fine enough inline filter unless you have/get a real clean tank.
Cosky's great (free) online manual: http://cosky0.tripod.com

forum links to common technical issues

If you really like this site and you would not like to see it vanish soon, have a look there: Urgent: Future of HondaCB650.com Forum

imandrewparks
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Joined: Thu Feb 11, 2016 11:48 am

Re: 82' CB650 Carb not pulling fuel

Postby imandrewparks » Wed Mar 23, 2016 11:54 am

Well the fuel is flowing so that's a success! Unfortunately when I flipped the petcock switch my carbs immediately started pouring gas. I rebuilt them when I first got them, but never used any sealant or grease or anything to hold the gaskets in place, so I'm curious if that's why they are leaking. If that isn't the case do you have any idea what could cause the immediate flood of gas?

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Folsoml
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Re: 82' CB650 Carb not pulling fuel

Postby Folsoml » Wed Mar 23, 2016 12:31 pm

You may be able to resolve the problem simply by tapping on the float bowls with something like a large screwdriver handle. Frequently on rebuilt carbs, the float needle will stick open when fuel is first introduced. If this does not fix it, you may need to pull the carbs back off a shine the float needle seat with metal polish. There may be a tiny bit of crud keeping the needle from seating. If the fuel is not coming from the float bowl overflow, you may need to replace the o-rings on the fuel rails.
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

cb650
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Re: 82' CB650 Carb not pulling fuel

Postby cb650 » Wed Mar 23, 2016 8:21 pm

First ? where are they leaking? bowls? feeder line?
Did you clean the tank out?!?!?!?!


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