Topic: Threaded vs. Non-threaded pilot jets in identical PD46C carbs (550K, Pics)

[VigCS]

Hi all,

I was an idiot and managed to damage my old rack of PD46C carbs, so I ordered a used set off of ebay.  They required extensive cleaning, and they bodies and passages are quite clean now, but all of the old bottom-end internals are still no good. 

I'm transferring all of the bottom end stuff from the damaged carbs (needle valves, floats, jets, mixture screws, etc) to the new cleaned rack.  The problem is, the new clean rack didn't have threaded pilot jets, I just had to yank them out with pliers.  The old set did have threaded pilot jets.  I've tried screwing the pilot jets into the new cleaned bodies, but they won't go.  Looking down in the pilot jet hole, they both look identical on each rack. 

I've attached a pic of a pilot jet from the ebay carbs (which are completely clogged) vs the carbs that I damaged (which are threaded and completely clear).  Does anybody have any idea why two racks of PD46C's would have threaded vs. non-threaded pilot jets?  Both are size 42.

This is all that stands between me and getting this bike running.  Thanks!!

[bollingball]

I don't know why they are different. It could be a (PO) put the wrong jets in like you are trying to do now. I do know if you keep trying to put a square peg in a round hole you will be looking for another set of carbs. I don't see how they can look identical if one has threads and one does not. Clean the ones that are clogged. Dirty does not mean no good press in jets are getting hard to find. At lease for my PD42b carbs.

               Ken

[TwoTired]

Perhaps you found a very early set of carbs that still had the screw in jets?  I didn't know there were any.

Jets are metal an can be cleaned effectively, with not too difficult an effort.

So, either clean them and reinstall the swagged in jets.  Or, take the carbs to a machinist to have threads cut in the bodies to accept the screw in type.

Or, mash the screw in type into the swagged holes with a BFH, and pray it seals correctly and the jet deforms well enough to stay in the holes.  You could also glue them into the body with a fuel proof Loctite product.

Cheers,

[VigCS]

Perhaps you found a very early set of carbs that still had the screw in jets?  I didn't know there were any.

Jets are metal an can be cleaned effectively, with not too difficult an effort.

So, either clean them and reinstall the swagged in jets.  Or, take the carbs to a machinist to have threads cut in the bodies to accept the screw in type.

Or, mash the screw in type into the swagged holes with a BFH, and pray it seals correctly and the jet deforms well enough to stay in the holes.  You could also glue them into the body with a fuel proof Loctite product.

Cheers,

I just went digging through a big box of parts and somehow found a set of 42 push in pilot jets that are clear!  There's a chance she'll run today, haha. 

On another hand, do any of you know where there are supposed to be O-rings in the bottom end?  The ebay set had O rings at the end of the mixture screws and that's it.  I feel like there should be one at the end of the main jet shaft.

Thanks!!

[bollingball]

No orings on mine I have two sets PD42 a&b. Mixture screws should have spring,oring and metal flat washer. I don't know about the 46 series

Let us make sure we are talking about the same thing!! my carb bodies are PD 42b series and have slow or pilot jets that are 35 with 105 mains. My other set PD42a series have 40 slow or pilots and 110 mains. What is stamped on the pilot jets of yours?


                Ken

[VigCS]

No orings on mine I have two sets PD42 a&b. Mixture screws should have spring,oring and metal flat washer. I don't know about the 46 series

Let us make sure we are talking about the same thing!! my carb bodies are PD 42b series and have slow or pilot jets that are 35 with 105 mains. My other set PD42a series have 40 slow or pilots and 110 mains. What is stamped on the pilot jets of yours?


                Ken

The pilots are 42 and the mains are 105, which aren't stock.  The bike has an aftermarket exhaust and pod filters on it (going back to airbox soon).  I believe the o-ring configuration of the 46 is also the same for the mixture screw.  Thanks .

I've been surviving on my XJ550 Seca while working on the Honda .   

[bollingball]

I hate people with back up bikes If I can help just ask

                     Ken

[scottly]

Or, mash the screw in type into the swagged holes with a BFH, and pray it seals correctly and the jet deforms well enough to stay in the holes.  You could also glue them into the body with a fuel proof Loctite product.

Cheers,

Lloyd, did it ever occur to you that noobs might not realize that you are trying to be funny when you make statements like this, and might actually take your advice?

[bollingball]

TT: I was with you up to the or part 
But I thought it was funny

              Ken