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General Category => Maintenance => Topic started by: fj11.5 on October 11, 2011, 11:46:22 PM

Title: needle and seat part difference,s
Post by: fj11.5 on October 11, 2011, 11:46:22 PM
Hi all, I've been given a complete new in packets needle and seat set, other than the center hole , is that the only difference gravity fed and fuel pump parts , as these are for a 93  model , mine is 84
Title: Re: needle and seat part difference,s
Post by: Arnie on October 12, 2011, 08:58:02 PM
Yep.  Big hole for gravity, small hole for pump.

Arnie
Title: Re: needle and seat part difference,s
Post by: fj11.5 on October 13, 2011, 01:08:07 AM
Cool  thanks, , now to fuel pump. Or drill holes out   :wacko3:
Title: Re: needle and seat part difference,s
Post by: andyb on October 13, 2011, 08:10:27 AM
Is the float needle different for the different seat size, or just uses a different portion of the sealing tip?  Iono.

Title: Re: needle and seat part difference,s
Post by: weymouth399 on October 13, 2011, 08:21:36 AM
I believe that slowoldguy (David R) has put fuel pump carbs in his bike (85 I think) w/o any mods to the carbs. Fuel inlet will be the only problem and that's not that big of a deal. He says it runs fine.
Maybe he will chime in.

Bob W
Title: Re: needle and seat part difference,s
Post by: andyb on October 13, 2011, 09:07:10 AM
David R uses the wrong tires, don't ever listen to him for advice.
:empathy3: :empathy3:

:blum1:
Title: Re: needle and seat part difference,s
Post by: racerrad8 on October 13, 2011, 11:20:33 AM
You are working to hard...

You can just use your old brass seats, they never wear out. It is the rubber tip of the needle that wears. You can use the new o-rings from the new seats on the old ones and then use the new needles.

And to answer Andy's question; the needles are all the same, it is just the hole size that changes. Now, with that said the float height had to be set differently as the needle goes deeper into the larger hole to seal.

Randy - RPM
Title: Re: needle and seat part difference,s
Post by: andyb on October 13, 2011, 01:41:36 PM
That's what I figured, it'd make the most sense to have just a single needle if possible, fewer parts to stock.

Thanks!
Title: Re: needle and seat part difference,s
Post by: fj11.5 on October 13, 2011, 05:59:50 PM
Thanks everyone, makes sence randy, will save trashing the new seats with a drill, ,had a fuel pump for awhile, but had overflow issues,, , what tyres Does David use , they the old Harley style lol , I'm using metzeler and dunlop at the moment, but have a pirelli for the front waiting , so I shouldn't make jokes about hardly desirable,s
Title: Re: needle and seat part difference,s
Post by: SlowOldGuy on October 17, 2011, 06:07:25 PM
The pump-type carbs work so well on my '85 that I totally forgot I had them installed.  I used one of the T fuel fittings from the old set as the single inlet on the new set.  I think Randy offers a replacement fitting for the center carbs which would allow retention of the double inlet setup.

And damnit I can't think of a good come-back to andyb.  :-(

"Oh yeah!  Well I faked mine too!" (name that movie)

DavidR.
Title: Re: needle and seat part difference,s
Post by: Pat Conlon on October 17, 2011, 06:55:41 PM
Harry met Sally?
Title: Re: needle and seat part difference,s
Post by: Flyover Country Joe on October 17, 2011, 09:24:59 PM
Quote from: andyb on October 13, 2011, 09:07:10 AM
David R uses the wrong tires, don't ever listen to him for advice.
:empathy3: :empathy3:

:blum1:

andyb, You're right about those tires, he uses those tires that don't have any tread on the sides :lol: :bye2:
                                                                        Joe
Title: Re: needle and seat part difference,s
Post by: SlowOldGuy on October 18, 2011, 11:38:11 AM
Hey Joe,
Nice riding with you in Arkansas last week! 

The ticket slowed us down a little, but I really enjoyed the pace.  It allowed me to gain back some confidence I lost after hitting gravel back in the spring.  I'm still a little spooked from that.

Once the ticket clears deferred adjudication hopefully I'll be back up to full speed.

Also, great kid you have there, everyone was impressed with him.

DavidR.

Title: Re: needle and seat part difference,s
Post by: SlowOldGuy on October 18, 2011, 02:11:19 PM
Pat,
"All of Me" with Steve Martin. 

His not-so-great come-back when Madelyn Smith is leaving him and tells him that she faked all of her orgasms.

DavidR.
Title: Re: needle and seat part difference,s
Post by: Flyover Country Joe on October 18, 2011, 07:04:22 PM
David,
  Dan & I really enjoyed meeting  & riding with you guys. When we stopped on Push Mtn. Rd, I explained to him lean forward and look over my inside shoulder, you could tell when the light came on for him. After that, we had a fighting chance of keeping you all in sight. Well, almost :rofl:. I understand what you mean about the gravel, I watched the video you posted from your spring trip. It looked like a high pucker factor moment, for sure.
Dan's mom & I appreciate the positive feedback, we think he's pretty exceptional too! Of course, we might be a little biased....  He is still talking about that 250 Ninja.....I'm not arguing either.... :good2:
                                                                                  Joe
Title: Re: needle and seat part difference,s
Post by: 1wormsway on July 19, 2013, 03:02:58 PM
Quote from: racerrad8 on October 13, 2011, 11:20:33 AM
You are working to hard...

You can just use your old brass seats, they never wear out. It is the rubber tip of the needle that wears. You can use the new o-rings from the new seats on the old ones and then use the new needles.

And to answer Andy's question; the needles are all the same, it is just the hole size that changes. Now, with that said the float height had to be set differently as the needle goes deeper into the larger hole to seal.

Randy - RPM
I know this is an old thread, but do not feel the need to start over with this one. Just would like to put my two pennies in for anyone whom might happen along looking for this particular info.  Currently have both parts in front of me, ie. 25G-14107-23-00 and 3CF-14107-15-00 and I find no discernable difference. This being both on a visual level and measuring by feel with the blunt end of a drill bit. There may in fact be a micro difference that I am missing without having at my disposal a more precise means of measuring, although I have never so much as had to reset float level when switching from one part number to the other. I believe the part # difference is in # alone and was probably a way of feeding the dealerships more stock, or just making older # obsolete. Has any body tried to order the 25G's recently ?
Title: Re: needle and seat part difference,s
Post by: racerrad8 on July 19, 2013, 06:03:28 PM
Quote from: 1wormsway on July 19, 2013, 03:02:58 PM
I know this is an old thread, but do not feel the need to start over with this one. Just would like to put my two pennies in for anyone whom might happen along looking for this particular info.  Currently have both parts in front of me, ie. 25G-14107-23-00 and 3CF-14107-15-00 and I find no discernable difference. This being both on a visual level and measuring by feel with the blunt end of a drill bit. There may in fact be a micro difference that I am missing without having at my disposal a more precise means of measuring, although I have never so much as had to reset float level when switching from one part number to the other. I believe the part # difference is in # alone and was probably a way of feeding the dealerships more stock, or just making older # obsolete. Has any body tried to order the 25G's recently ?

Jeremy,

Let me take this time to correct information you have posted based on measuring with the proper tools, the correct information about the part numbers and the experience associate with FJ carburetors.

This has been covered several times, but since you have brought up this old thread, I want to make sure it is posted again.

There are in fact, two different needle seats for the FJ carburetors depending on if they were early model gravity or late model fuel pump feed. The difference is the size of the hole that is the inlet supply for the fuel. Unless you have a number/letter drill bit set that is in 1000ths of an inch, you probably cannot measure the difference.

I have both letter & number drill bits as well as a dial caliper that I use for measuring. I have measured them long ago to determine the actual difference of the seat which is;

Gravity; 2.3mm or .090"
Fuel Pump; 1.5mm or .060"

If you were to remove the screen from the tip of the needle seat you will see the numbers stamped into the body indicating the size of the original Yamaha seats. Here is a 2.3mm seat, sorry I do not have a 1.5mm seat readily available.
(http://i1215.photobucket.com/albums/cc517/racerrad8/46642e5f-1185-406d-8660-5b49b3859e1b_zpsa12605a5.jpg) (http://s1215.photobucket.com/user/racerrad8/media/46642e5f-1185-406d-8660-5b49b3859e1b_zpsa12605a5.jpg.html)

I personally can see the difference in the hole size just by looking at them, but I took a couple of pictures so you hopefully can see the difference with the zoom of the camera. The 2.3mm hole is on the left.
(http://i1215.photobucket.com/albums/cc517/racerrad8/carbseat001_zpseaa3f820.jpg) (http://s1215.photobucket.com/user/racerrad8/media/carbseat001_zpseaa3f820.jpg.html)

Closeup
(http://i1215.photobucket.com/albums/cc517/racerrad8/carbseat002_zps818ba3a4.jpg) (http://s1215.photobucket.com/user/racerrad8/media/carbseat002_zps818ba3a4.jpg.html)

You can also click on each photo and that will take you to the Photobucket page and allow you to zoom in even closer if needed.

Now, the difference in the size of the hole means the needle valve will not sit as deep into the smaller hole and deeper in the larger hole. So, the floats should be adjusted according due to the difference of the holes size & contact point upon the needle.

The reason the smaller orifice seat is used with the fuel pump version bike is the line pressure applied to the tip of the float valve. If you try and use 2.3mm seats on the fuel pump bike they usually bypass the seat and flood the carburetors.

Finally, the actual difference in the part number is at the back of the number not the beginning prefix; -15 or -23 which is the size of the hole of the seat.

I hope this clears up any doubt you have that there are in fact two different needles seats that are required for use on the FJ depending on the application they are used on.

Randy - RPM
Title: Re: needle and seat part difference,s
Post by: FJmonkey on July 19, 2013, 06:36:16 PM
I concur with Randy, I switched a FP set of carbs over to GF and forgot to check the float height.  :dash1: :dash1: :dash1: Took the carbs off and pulled the bowls, and reset the float height....
Title: Re: needle and seat part difference,s
Post by: movenon on July 19, 2013, 06:36:46 PM
+1    :good2: :good2: :good2:

George
Title: Re: needle and seat part difference,s
Post by: 1wormsway on July 19, 2013, 09:24:10 PM
Randy,

I stand corrected. Two different size seats. Thanks for the clarification on my mistake. Been awhile since I had to deal with needle and seat. Old parts were mislabeled and upon searching further found the 1.5's. Yes there is an obvious difference.  Appreciate your sharing of knowledge and will look forward to you correcting me again, probably sooner than later. Cheers, and yamaha ha ha to all

Title: Re: needle and seat part difference,s
Post by: Pat Conlon on July 19, 2013, 10:49:19 PM
I will copy Randy's most excellent post and place it over in the Carb. Files for future reference.

Thank you Randy.