Author Topic: PD carb press-in slow jet fell out  (Read 1398 times)

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Offline Davidov

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PD carb press-in slow jet fell out
« on: December 03, 2017, 07:27:03 AM »
I got my 78 CB750F out yesterday to stretch its legs, check the tires, and get some fuel.
It started running poorly and initially thought I just needed to switch to reserve. Limped to a gas station, but fuel wasnt the issue.
Got it back home and started all the basic checks.

After a short time of prodding, I found the Pilot/Slow jet of #4 carb laying in the float bowl.
These are the press fit type.

Anyone had issues with this before? Is there a way to secure it better?
-David

Offline strynboen

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Re: PD carb press-in slow jet fell out
« Reply #1 on: December 03, 2017, 08:58:27 AM »
400 four have a metal clips..holding the jet nice up...a nev o ring ??,,is there korosion..make it fitt loose
« Last Edit: December 03, 2017, 09:17:30 AM by strynboen »
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Offline Deltarider

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Re: PD carb press-in slow jet fell out
« Reply #2 on: December 03, 2017, 09:49:00 AM »
I got my 78 CB750F out yesterday to stretch its legs, check the tires, and get some fuel.
It started running poorly and initially thought I just needed to switch to reserve. Limped to a gas station, but fuel wasnt the issue.
Got it back home and started all the basic checks.

After a short time of prodding, I found the Pilot/Slow jet of #4 carb laying in the float bowl.
These are the press fit type.

Anyone had issues with this before? Is there a way to secure it better?
I had this once and - mind you - the slow jet on my bike is even the screw in type (that I obviously hadn't fastened enough). You could use to some glue maybe?
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Offline BobR

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Re: PD carb press-in slow jet fell out
« Reply #3 on: December 03, 2017, 10:12:45 AM »
 Seems like a poor move to change the design from screw in to push in. At work when I have issues with press fits and auto trans parts I sometimes use my engraving tool and lightly nurle or rough up a surface for a tighter fit. Not sure if Id want to go that route on a carb though. maybe a dab of this. Bob

https://www.seton.com/loctite-680tm-retaining-compound-high-strength-high-viscosity-ee176.html
« Last Edit: December 03, 2017, 12:50:19 PM by BobR »
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Offline flybox1

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Re: PD carb press-in slow jet fell out
« Reply #4 on: December 04, 2017, 06:53:00 AM »
Seems like a poor move to change the design from screw in to push in. At work when I have issues with press fits and auto trans parts I sometimes use my engraving tool and lightly nurle or rough up a surface for a tighter fit.
^^ this.   Works quite well. 
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Offline madmtnmotors

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Re: PD carb press-in slow jet fell out
« Reply #5 on: December 04, 2017, 02:57:22 PM »
Seems like a poor move to change the design from screw in to push in. At work when I have issues with press fits and auto trans parts I sometimes use my engraving tool and lightly nurle or rough up a surface for a tighter fit.
^^ this.   Works quite well. 

I would try this a little at a time at first. Rough up the surface of the jet near the shoulder that would be near the outermost portion of the seat instead of making any modifications to the carb itself. New jets are easier to get (and replace) than the carb body. Maybe some small stakes (dimples) in the outside of the jet done with an awl? Don't get carried away and don't strike too hard!
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Offline Dunk

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Re: PD carb press-in slow jet fell out
« Reply #6 on: December 05, 2017, 05:45:27 AM »
I would use retaining compound if it's really loose, not 680 though. 609 or 620 is plenty. Remember, you may want to remove the jet eventually. Just a dab will do ya if it's not really loose. You may also try hitting the jet OD with a center punch a few times. If it's them really tight in the carb body lightly file down the raised area until it goes in without tearing up the carb body.

Offline chuter1

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Re: PD carb press-in slow jet fell out
« Reply #7 on: December 05, 2017, 07:50:52 PM »
      If it were mine this is what I would do.  Take the jet and solder around the part that is pushed into the seat. Soldering it will add a small amount of material so when it is pressed in it will have that press fit that you want. If you add to much solder you can just heat it up and remove what you don't need..  A soldering gun will work perfect, you do not have to use a torch or something that gets that hot. Try it on a scrap piece of brass until you feel confident with the process.  Chuter.