Author Topic: Keihin 32 mm jet sizes (standard)  (Read 8917 times)

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Offline Garn

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Re: Keihin 32 mm jet sizes (standard)
« Reply #15 on: March 25, 2015, 05:31:28 AM »
As far as I recall, it need not be a good fit, as it acts as a little buffer for part of the retaining clip (that fits in the groove on the main jet).  Dean says it is not meant as a fuel seal.
Could be completely wrong, however I have a job to do on carbies soon, so I'll try and remember to investigate further!
RegardZ.
Kawasaki Z1, Z1A, Z1B, Z900-A4 and TX500A
    Sydney, Australia

Offline U000dsr

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Re: Keihin 32 mm jet sizes (standard)
« Reply #16 on: March 25, 2015, 07:33:12 AM »
As far as I recall, it need not be a good fit, as it acts as a little buffer for part of the retaining clip (that fits in the groove on the main jet).  Dean says it is not meant as a fuel seal.
Could be completely wrong, however I have a job to do on carbies soon, so I'll try and remember to investigate further!
RegardZ.


Thanks.  Will be waiting.

Offline dean

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Re: Keihin 32 mm jet sizes (standard)
« Reply #17 on: March 25, 2015, 05:29:39 PM »
It is indeed a  "fuel seal "   :D
The passage the rubber plug blocks is only the access for installing/ removing the pilot/slow jets. The slow/ pilot are not supposes to pull fuel directly from the bowl and this would happen if the plug did not seal or was missing completely. 

The source of fuel for the pilot/slow jets is a passage circuit from the main jet side, not the fuel bowl.

Offline johnmurphy

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Re: Keihin 32 mm jet sizes (standard)
« Reply #18 on: March 26, 2015, 03:41:42 PM »
I have been using a work around for these rubber plugs in the slow / pilot well which is about 5 mm

inside diameter. It has held up for a few thousand miles without any detrimental effects. I use a

very short section of Tygon tubing commonly used as fuel line for lawn and garden gas powered

equipment. I have used 3/16" outside diameter by 1/8" inside diameter but it also comes in 0.211"

outside diameter by .117" inside diameter. I then take a number 6 brass round slotted head machine

screw and screw it into the Tygon tubing after the Tygon tubing is inserted into the well. The

diameter of the head of the #6 machine screw is larger than the inside diameter of the well so it

doesn't go into the well and supports the clip for the main jet. I start out with a 1/4" long brass

screw and shorten it slightly so that it doesn't block the passage between the slow / pilot well

and the main jet well (this is critical or you will block the fuel passage). The same for the

length of Tygon tubing. I typically cut it to about 0.22" to 0.23" long. Depending on how classy

your local hardware store is, you can get a foot of tubing and two screws for less than 2 USD.

Offline Garn

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Re: Keihin 32 mm jet sizes (standard)
« Reply #19 on: March 27, 2015, 10:21:00 AM »
Dean I like your second answer better! I did base my answer on your first posting!
However, on examination, the 1st posting was on my bad purchase of seals
RegardZ
« Last Edit: March 27, 2015, 10:27:50 AM by Garn »
Kawasaki Z1, Z1A, Z1B, Z900-A4 and TX500A
    Sydney, Australia

Offline Garn

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Re: Keihin 32 mm jet sizes (standard)
« Reply #20 on: March 27, 2015, 10:22:57 AM »
Great solution JohnMurp!..... Simple and clever.

RegardZ
Kawasaki Z1, Z1A, Z1B, Z900-A4 and TX500A
    Sydney, Australia

Offline U000dsr

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Re: Keihin 32 mm jet sizes (standard)
« Reply #21 on: March 30, 2015, 02:40:48 PM »
Those black plugs.  I'm looking at the one I have and it doesn't seem like it's rubber.  More like a hard plastic plug.  I placed an o ring on the plug hopefully that will seal the fuel issue there.  I also put the same size o ring on the main jet.  Hoepfully that will take care of that too.  Fuel is murder the rubber parts.  I can't complain.  Nothing last for ever. 😁

Offline dean

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Re: Keihin 32 mm jet sizes (standard)
« Reply #22 on: March 31, 2015, 02:16:50 PM »
They were once somewhat pliable.   

also,  nitrile, fluorosilicone, or urethane O-rings are "fuel safe" 

Offline TXRAT

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Re: Keihin 32 mm jet sizes (standard)
« Reply #23 on: April 03, 2015, 04:09:22 AM »
I found that fine grade sand paper to a larger plug works great. Had a hell of a tome finding parts for my kiehens too. Modified some yamer carb plugs that had too large a diameter with a bit o 1000 grit until it fit snug, harbor tools has or had a o-ring kit with the correct main jet size.

Offline johnmurphy

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Re: Keihin 32 mm jet sizes (standard)
« Reply #24 on: July 25, 2015, 12:27:53 AM »
My TX500A with 32 CV Keihins began running rich at mid range and high RPM, so I removed the carbs for inspection. After removing the float bowl and clip that holds the main jet, the plug fell out of the well that holds the pilot and slow fuel jet. The Tygon hose that I had used as a plug had shrank and hardened while exposed to fuel over time. Evidently fuel had been leaking past the plug, bypassing the main fuel jet and causing the rich condition.

   THE POINT IS THAT WHAT I PREVIOUSLY POSTED IS ONLY A TEMPORARY FIX!

My next temporary fix was to use some Gates vacuum hose (Gates 27041 available at O'Reillys). It has an inside diameter of 0.109 inches and an outside diameter of 5.7 mm. The outside diameter of the hose is too large to fit into the 5 mm slow fuel jet well. So I slipped a short section of the hose over a 1/8 inch shaft and chucked it up in a Dremel tool. Using  my wifes coarse emery board, I turned down the outside diameter of the hose so that it was a tight fit into the well (without being mounted on the 1/8 inch shaft). I then cut a short ( 0.165 inch ) section off and pressed it into the well. I screwed a #4-40 by 1/4 inch brass machine screw with brass washer into the inside diameter of the hose. This has worked well while I was working on a more permanent solution.

   Now for what I consider to be the permanent solution. I purchased two press in Keihin jets from Jets-R-Us ( part number 99201-601 which are 4.95 mm otside diameter ). Since I donít have a mini lathe, as some of you may have, I used one of my drill motors. I took the O ring off the jet and chucked the end opposite the O ring in a drill motor. With a fine file I put a 0.037 inch by 45 degree chamfer on the end of the jet that I had removed the O ring. This chamfer serves two purposes; first it makes sure the end of the jet doesn't block the fuel passage between the slow fuel jet well and the main fuel jet well, secondly it makes it easier to slip the O ring on. Next I took some 1/4 inch copper tubing and cut some 0.125 inch lengths off. One quarter inch copper tubing is suppose to have 0.030 inch wall which would give a 0.190 inch (4.83 mm) inside diameter. What I found was that all of the tubing I measured had a wall thinner than 0.030 inch wall which allowed the tubing to slip over the jet. I soldered up the jet hole and soldered the ring of copper on the jet approximately 0.181 inches from the O ring end. It helps to have a steady hand and use thin electronic solder (1/32 inch diameter) so that you don't get solder all over the jet. If you get some solder where it is not suppose to be, chuck the assembly in a drill motor and clean it up with a fine triangular file. I then chucked the O ring end of the jet in a drill motor and with a Dremel cut off wheel and fine flat file I cut the end of the jet opposite the O ring so that the copper ring was 0.115 inches long. You will mainly be cutting excess brass from the jet. The whole assembly should now be 0.296 inches long (0.181 + 0.115 = 0.296).

For those of you with a mini lathe and a piece of brass stock, Iím posting the dimensions of the final product.
   
So there you have it, pick your poison.


Offline retrostude

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Re: Keihin 32 mm jet sizes (standard)
« Reply #25 on: January 25, 2018, 04:57:34 AM »
Recognized the Vmax reference for the plug substitute, pulled my spare Vmax parts carbs out, voila. Plugs from those work great with a simple trim. Awesome!