'81 cb650c idle jets, how do i clean them?

If it's broken or just needs tweaked

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cb650
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Re: '81 cb650c idle jets, how do i clean them?

Postby cb650 » Thu Aug 04, 2011 4:34 pm

From the factory the 81 was 120 and in 82 they went 118.
Did you clean the tank out?!?!?!?!

blue83ranger
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Re: '81 cb650c idle jets, how do i clean them?

Postby blue83ranger » Fri Aug 05, 2011 9:05 pm

I just saw on ebay that the sirius carb people are selling brand new press in style idle jets. They don't answer emails till monday so i'm going to email then and ask about them. I would've thought the carb side of things would be the problem after you pull them out but if they sell the jets they would know what's best.
'83 Ford Ranger 302 4x4
'83 XR500R
'77 & '79 XL75
'85 ATC250SX
'85 Tecate
'87 TRX250X
'97 TRX300 4x4
'04 TRX450R
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nashbuilder
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Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Sat Apr 28, 2012 12:33 pm

Did you figure out how to clean the idle jets on the 81 CB650 Custom ( Carbs are VB44A) - which has pressed in idle jets. Does anyone have experience with these carbs? I need to get these idle jets cleaned out today if possible.

blue83ranger
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Re: '81 cb650c idle jets, how do i clean them?

Postby blue83ranger » Sat Apr 28, 2012 2:26 pm

I did not, the owner thought it would be best just to buy a used set of carbs with the screw in idle jets instead. sorry i couldn't help more.
'83 Ford Ranger 302 4x4
'83 XR500R
'77 & '79 XL75
'85 ATC250SX
'85 Tecate
'87 TRX250X
'97 TRX300 4x4
'04 TRX450R
2 '80/'81 JD spitfires

nashbuilder
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Joined: Thu Mar 08, 2012 8:30 pm

Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Mon Apr 30, 2012 4:58 pm

Thats what I seem to be hearing. Not sure what to do, thanks for letting me know though.

cb650
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Re: '81 cb650c idle jets, how do i clean them?

Postby cb650 » Mon Apr 30, 2012 5:13 pm

Patience and a wire strand. I've always had 2 good sets of 81 carbs so never had to remove the idle jets. I can only think of ways to remove them that would destroy the jets. Now have a couple sets of 82's to play with if need be.
Did you clean the tank out?!?!?!?!

nashbuilder
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Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Tue May 01, 2012 10:01 am

Does anyone know which carb rebuild kit goes with these carbs. Everything I see is the K&L 18-2572 kit but looking at the pictures of these the float needle is not the same as mine along with the jets. I know many of these sites use a generic picture so I may not be looking at my package. Do anyone have advise to which rebuild kit to buy for the 81 CB650 Custom which has the VB44A carbs?

Todd Richards
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Re: '81 cb650c idle jets, how do i clean them?

Postby Todd Richards » Thu May 03, 2012 9:16 am

if you have the carburetors completely dissassembeled & separated ( all o-rings & non metal parts removed) I would hightly reccomend an ultrasonic cleaning with the heater on to get the cleaning fluid & parts hot, helping to dissolve the gunk inside the jet.. Carburetor cleaner, pine sol should do the trick, especially with the heat!

I have even heard of using acetone... I never have though, as that stuff is really nasty & will quickly dissolve any o-rings, some plastics.

If you do use it be sure to be outside, to provide adequate ventillation

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Volker_P
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Re: '81 cb650c idle jets, how do i clean them?

Postby Volker_P » Thu May 03, 2012 2:44 pm

Todd Richards wrote:I have even heard of using acetone... I never have though, as that stuff is really nasty & will quickly dissolve any o-rings, some plastics.

True. Better don't try out with the floats!
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nashbuilder
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Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Fri May 04, 2012 11:40 am

I am planning on dismantling the rack and would like to use the ultrasonic method. I might also use Chem Dip. The ultrasonic sounds like it would insure those pilot jets get cleaned more then chem dip would. Does anyone know which carb rebuild kit has all o-rings and parts I need?


nashbuilder
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Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Tue May 08, 2012 5:18 pm

DIsmantle and ultrasonic cleaning went well except for 1 thing. The choke mechanism is not working properly. I took pictures and video for you to see what its doing. Every picture I have and what people have said on other post I have done. When I pull the choke perch up it does not engage the choke plate rods. When I push the choke plate rod they work just fine. Something with the choke perch is not engaging the actual choke rods. Any ideas.

http://www.youtube.com/watch?v=JlITU8MhQdM

Todd Richards
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Re: '81 cb650c idle jets, how do i clean them?

Postby Todd Richards » Tue May 08, 2012 7:42 pm

from what i can see it is that central spring that is the problem.....

Have you rechecked you individual carburetor alignmnet on the rack to see if there is a possible misalignment, possibly binding the choke rods?

it is very finiky, and if any of the coils are crossed, you might as well dissassemble and start that part over, if you can not get them lined up as assembeled. all the coils need to be aligned. and that little tab needs to be on the inside of them, keeping them functioning as a coil spring, throughout operation.

I went thru this a few months back and can speak of this from experience, Be very careful with this spring, you accidentilly ruin it, and there is no replacements available via OEM. EBay, if you are lucky!

do a search for McGreggor Carburetor Rebuild Services" download the PDF, it should help you with the choke spring. The carburetor he speaks of is slightly different from yours, but that darned choke spring and associated hardware are near(if not identical)

I hope this helps you

Todd Richards
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Re: '81 cb650c idle jets, how do i clean them?

Postby Todd Richards » Tue May 08, 2012 7:54 pm

I just watched the video a second time and am now pretty sure you have an alignment issue related to both the carburetor banks and possibly to each other individually? Your choke spring is definatly needing to be straightened out! There is a very small circular shoulder the the first winding should locate upon, this is key to getting a proper winding (this shoulder is located on the left side choke linkage) remember that tab underside needs to be inside of the coils, to keep them straightened.

once you have this completed, gently push at the coils and they will easily conform to a circular coil. recheck your alignment by putting the choke thru its range of motion.

Good Luck!

nashbuilder
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Re: '81 cb650c idle jets, how do i clean them?

Postby nashbuilder » Wed May 09, 2012 11:39 am

You were correct. I had someone else give me the same advise and after a little moving the carbs around and mounting them all together it is working like a charm. Thanks for the tips and I hope this dismantling and cleaning I did fixes the problem. I will find out this evening. Bourbon and cigar are calling my name if it runs tonight.


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