Carb idle jet oring?

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JimmyC
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Carb idle jet oring?

Post by JimmyC » Mon Feb 04, 2019 9:54 am

I am sorting out a misfiring cylinder on my truck and suspect it is fuel mixture related. I removed the jet cover and pulled the jets. The slow-running jets (1-40-28, 700.1.08.405.1/60) had o-rings in their seats. The drawing in the parts book does not show an o-ring here.

Does anyone know if there are suppose to be o-rings here?

Thanks!!
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect

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rmel
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Re: Carb idle jet oring?

Post by rmel » Mon Feb 04, 2019 10:47 am

Going though some Carb tweaks and fixes myself on my 712 project.
O-rings on the Injectors as they would experience fuel under positive
pressure from the accelerator pump. No O-rings or washers for the Idle
jets they operate under a vacuum. So your right they don't belong there.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

boeing7873
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Re: Carb idle jet oring?

Post by boeing7873 » Mon Feb 04, 2019 6:33 pm

As far as I remember, there are two types of idle jets. Old type and new type. Only the new ones have the o-ring. Check these pictures on Ebay.

https://www.ebay.com/itm/ZENITH-NDIX-CA ... :rk:8:pf:0

https://www.ebay.com/itm/ZENITH-NDIX-CA ... Sw7NNUIrbI
Jerome
CRJ Driver

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rmel
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Re: Carb idle jet oring?

Post by rmel » Mon Feb 04, 2019 7:48 pm

Thanks for posting that link! Interesting, well my idle jets are definitely the older style
as per the Pinz doc's. The telltale is there's a seat for an O-ring with thee newer ones.
Kind'a not necessary though, as far as a fuel leak, always under a vacuum -- one could
argue though there could be a very minor vacuum leak.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

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Hotzenplotz
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Re: Carb idle jet oring?

Post by Hotzenplotz » Tue Feb 05, 2019 12:58 pm

Gentlemen
don't get confused

Image
items 20 and 21 on tis pic are the main jet and the idle jet underneath the lid. neither of these jets has an o-ring, but the pump jets 36 do

Image

The idle mixture screw here in the throttle assemby number 11 does have an o-ring number 12
these pics show version 2 and 3 of the carbs. version 1 has the idle adjuster screw with the larger head
Cheers
Albert
========================
My Pinz has NEVER been with any army

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rmel
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Re: Carb idle jet oring?

Post by rmel » Tue Feb 05, 2019 1:41 pm

Hmmm, interesting, well it is confusing, especially if your reference
is the standard hard copy Ersatzteilkatalog, Group 1 40. Which is far
more cluttered with breakouts than your images and shows no reference
to O-rings for the Idle valves #62 and #63 (spring). I guess one should
always double check both the hard copy against the www.Puch.at
site for discrepancies. They must be more up to date than something
that was printed in 1985 (or older) :?
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

JimmyC
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Re: Carb idle jet oring?

Post by JimmyC » Wed Feb 06, 2019 9:26 am

Thanks for all the help. So mine had o-rings on the idle jet and has run fine until recently. I have taken them off. The o-rings onthe idle mixture screw (small type) are missing. I will put some there.

My front is small screw and my back is large screw. I don't have a good picture of the large screw type. Does it have an O-ring on the mixture adjustment screw?

And finally the idle cut-off valve. It doesn't have a gasket or a soft washer and it is not tapered threads. It seems like it would leak. Do people put it on dry or use pipedope or hydraulic sealant?
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect

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pcolette
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Re: Carb idle jet oring?

Post by pcolette » Wed Feb 06, 2019 9:33 am

JimmyC wrote:
Wed Feb 06, 2019 9:26 am

And finally the idle cut-off valve. It doesn't have a gasket or a soft washer and it is not tapered threads. It seems like it would leak. Do people put it on dry or use pipedope or hydraulic sealant?
Dry.
Paul C.
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'73 Swiss 710M
'89 Puch 230GE
2002 MB G500 (For Sale)

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edzz
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Re: Carb idle jet oring?

Post by edzz » Wed Feb 06, 2019 10:36 pm

Assume you have looked at Jim's excellent Pinz carb pages :D
http://www.goatwerks.com/carbarticle.htm
http://www.goatwerks.com/carb.htm
Ed
75 710K (sold)
06 2WD Ural Patrol (sold)
69 2WD Rokon Trailbreaker 4 sale
A few Honda Trail 90's (all sold)

Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

JimmyC
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Re: Carb idle jet oring?

Post by JimmyC » Thu Feb 07, 2019 5:34 pm

My carb is back together and I will try it in the morning. Except for the extra orings on the idle jets, there was no obvious problem.
JIm L's instructions were great. I would only add one thing: Until you get your float level right, use the old top gasket; save your good gasket until you have the float adjusted, then check it again with the new gasket.

It would be smart to have a spare top gasket or two in case you have trouble with the float level when you put the new gasket on. Evidently not all gaskets are the same thickness.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect

JimmyC
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Location: Lafayette, LA and Highlands, NC
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Re: Carb idle jet oring?

Post by JimmyC » Thu Feb 21, 2019 8:19 pm

Runs great with clean carb. Must have been something in it.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect

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