Author Topic: Removing and Converting 81 CB 650 slow jets (deep pressed in)  (Read 3626 times)

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Offline dfoxengr

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I've been searching and couldn't find a good writeup on how to remove/replace these jets. There were a few threads on this forum but nobody seemed to have that particular answer.

I tried heat and a screw with slide hammer on one, but it wouldn't budge.

Also if anyone has any information on converting these to screw in type I would appreciate that too. Would drilling the stock jet oversized and then threading the inlet of the tube to insert a removable restriction orifice be a possibility? I have the ability to make the orifices at a machine shop, so I was thinking that would be a cheaper alternative to converting to real OEM screw in jets.

Offline dfoxengr

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #1 on: March 18, 2012, 07:09:47 am »
someone has to know how to remove these things?

bollingball

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #2 on: March 18, 2012, 07:53:17 am »
Not sure what carbs you have. ## PD s?? If they are press in you grab them with a pair of pliers  Some people us leather so not to scar the jet just pull and twist. Try some PB blaster Let it soak a little and try again. I would not try to convert them.

Give us the numbers on the side of the body maybe they have been changed. Do you see any place for a screw driver or wrench. With the year you gave they should be press in PD carbs.

Ken

Offline dfoxengr

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #3 on: March 18, 2012, 08:50:03 am »
I guess not many people know that in 81, the 650 had a different CV carb than in 80 and 82. here is a picture of the slow jet. It is the one next to the main jet (closest to use in the picture) and is pressed down into that aluminum extrusion. This image was found on the forum here.



It is basically just like the 82 threaded in slow jet, but it is pressed instead of threaded. So to me, that only option I thought was a screw in slide hammer with heat. That didnt work the first time, but I was being fairly gentle.

Offline cmonSTART

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #4 on: March 18, 2012, 09:50:44 am »
That's just like my 81 GL1100.  To remove it I just let them soak in PB Blaster and then used the wood screw trick/slide hammer trick.  I had also previously boiled these carbs, too.  Maybe that helped. 

At least in the GL1100, after 81 they went to thread-in type slow jets. 
1981 GL1100 Interstate
1978 CB750F Project

bollingball

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #5 on: March 18, 2012, 09:56:56 am »
Yes they are a lot different than mine. Sorry about any misinformation.

Ken

Offline cb650

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #6 on: March 18, 2012, 10:23:49 am »
FYI the 82 was essentially the same carb and had screw in jets.
18 grand and 18 miles dont make you a biker

Offline dfoxengr

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Re: Removing and Converting 81 CB 650 slow jets (deep pressed in)
« Reply #7 on: March 18, 2012, 07:34:49 pm »
Right, I've read on some CB650 page through google that the guy converted his by just tapping the press-in section for the 82 threaded section of the jet. was hoping someone here had more info about doing that.

I tried the a wood screw and slide hammer. but I was not being too forceful. I guess I'll just get the propane torch out instead of the small butane torch I was using and put some more effort into pulling them out.


What is the stock jet for the slow jet too? I've found 36, 38...? Just want to get it right.