Kawasaki FH680V

[Merkava_4]

The carburetor uses two of these needle jets. Being that they have O-rings on them, does that mean they're supposed to be screwed in all the way making them non-adjustable ?

And are the needle jets going into an air feed passageway, or are they going into a fuel feed passageway ?

Image Link:
https://www.rcappliancepartsimages.com/ ... 283576.jpg

[bgsengine]

O-rings are there to provide for friction to hold adjustment in place there are some Zama carburetors like that too

[Merkava_4]

bgsengine,

So does that mean they're adjustable needles that are going into fuel passages ? That have welch plugs over the needles. I don't see no reason in removing the welch plugs unless the needles are adjustable. By the way, there's two needles because the engine is a twin cylinder I'm assuming.

[38racing]

O-rings are there to provide for friction to hold adjustment in place there are some Zama carburetors like that too

A few pennies cheaper that a spring?

[Merkava_4]

A few pennies cheaper that a spring?

Briggs & Stratton used to have some that had an O-ring, a washer, and a backup spring.

That was on the Two Piece Flow-Jet.

[bgsengine]

So does that mean they're adjustable needles that are going into fuel passages ? That have welch plugs over the needles. I don't see no reason in removing the welch plugs unless the needles are adjustable. By the way, there's two needles because the engine is a twin cylinder I'm assuming.

Well .. kinda ask yourself - what would be the point of having needles like that , if not meant to be adjusted? If they had cross-drilled holes (however tiny) then it'd be understandable since they would be jets (AKA Pilot Jets) but a solid tapered needle like that is an adjustment needle - and as being adjustable, obviously not something with a torque setting, so how else would they be held in place other than the o-ring providing friction (as the O.D. is compressed into the recessed hole the shoulder fits into) - then they are sealed with welch plug (or limiter plugs) which was pretty much their (no longer permissible) means of anti-tampering to comply with EPA compliance regulations...

[Merkava_4]

Well .. kinda ask yourself - what would be the point of having needles like that , if not meant to be adjusted? If they had cross-drilled holes (however tiny) then it'd be understandable since they would be jets (AKA Pilot Jets) but a solid tapered needle like that is an adjustment needle - and as being adjustable, obviously not something with a torque setting, so how else would they be held in place other than the o-ring providing friction (as the O.D. is compressed into the recessed hole the shoulder fits into) - then they are sealed with welch plug (or limiter plugs) which was pretty much their (no longer permissible) means of anti-tampering to comply with EPA compliance regulations...

I'm asking this question because I thought they might be pilot jets like on the Pulsa-Jet carburetor. I wanted to be sure before I tell the guy on LawnSite what to do. And like 38racing said, I'm used to mixture needles being held in place by backup springs. The O-rings threw me for a loop.

And tell the EPA that my 1968 Horizontal shaft Briggs & Stratton model 6B on my McLane edger with the adjustable Vacu-Jet carburetor runs cleaner than any of their tamperproof carbs could ever dream of.

[KE4AVB]

They are adjustable but most times you don't need to access them. If being remove you lightly seat them counting numbers each as you do so you can put them back in the original position. Here is a extract copy of the cut away view image from the service manual.


Service Manual is available at K&T Parts House website under Kawasaki.