TOPIC:

Hi gang, I know this topic has been discussed but I wanted to document on this forum my technique to get the carb tapped and the air correctors installed on a set a vm26ss carbs off of a 76 kz900. This could apply to almost any carb but not sure about if tap sizes would change. Ok so off we go!

First I started by fabricating my own version of the jets. I dug around looking for info on the jet size and found .6mm as the ID for the jet. Is this even correct? I found info on a manufacturer called LEDAR who made these in the past. The jets are 8mm long with 5mm x .8 external thread. Then I drilled out both ends with a #47 drill to a depth of about .100". Then just drilled through with a #71 drill which was the closest I had to .6mm.  I would be even easier to have taken a 5mm set screw and drill a hole through it but I made them out of brass instead. 

 

Then I cut a 1/32 slit in one end for a screwdriver. 

 

Once the jets were finished I made up a custom tapping block from a scrap pc of aluminum. I drilled a 6mm hole through the block since the shank of the tap measures just under 6mm. Now the tap fits through with a nice slip fit. No wobble here. 

 
 

Now it is time to tap the carbs. Place the tapping block flush on the mouth of the carb. Notice how the tapping block keeps the tap perfectly perpendicular to the face of the carb body. Do not attempt this without using a tap guide, It will not be straight!  Then I stacked a few washers over the tap so It would tap shallower then I needed it to go and tapped the hole until the washer and tap handle bottomed out.


 

Then removed tap and inserted the jet to see where its position was. It was a little proud so I removed one washer and tapped again.


 

Now the Jet sits just under the surface. Now all you do is repeat on all the other carbs and the jets will be exactly the same depth. Easy.

   

Nice work. IMHO way to much effort in trying to reinvent the wheel. Zed1015 sells the air corrector jets. Tapping the hole was pretty easy. The bore in the carb is already the correct size for the M5 tap. The tap followed the bore nicely and I didn’t notice any cant. As far as depth it’s was very simple to tap shallow, fit the jet, check depth, and adjust with another thread or two. I don’t think the depth of the jet matters, beyond aesthetic’s. Install time for me was less then 10 minutes from opening the package of jets to completion. 

wrote:

Nice work. IMHO way to much effort in trying to reinvent the wheel. Zed1015 sells the air corrector jets. Tapping the hole was pretty easy. The bore in the carb is already the correct size for the M5 tap. The tap followed the bore nicely and I didn’t notice any cant. As far as depth it’s was very simple to tap shallow, fit the jet, check depth, and adjust with another thread or two. I don’t think the depth of the jet matters, beyond aesthetic’s. Install time for me was less then 10 minutes from opening the package of jets to completion. 

Yes! a 1st or 2nd taper tap will follow the air bleed passage squarely unless you are really incompetent and i wouldn't drill 0.6mm for the Z900 VM26's.
It's the wrong size for those and the orifice is different between the VM22,24,26 and 28's etc..

Hi Zed. What would you recommend as the correct size for the VM26? Larger? 1mm? 

As far as the 26's I really need more clarity on which holes to tap for a 1000 as It is different sequence than the 900. I guess at my age Im a little thick. I have the air corrector jets already.

wrote:

As far as the 26's I really need more clarity on which holes to tap for a 1000 as It is different sequence than the 900. I guess at my age Im a little thick. I have the air corrector jets already.

Here is zed1015 e-bay pic to adress the jet positions.

i.ebayimg.com/images/g/oSQAAOSwC6xbP-hn/s-l1600.jpg

wrote:

As far as the 26's I really need more clarity on which holes to tap for a 1000 as It is different sequence than the 900. I guess at my age Im a little thick. I have the air corrector jets already.

I don't know why you thought the 900 location was different to the 1000 but they all go in the same air bleed to the needle jet tube ( AKA main jet holder or air pipe bleed etc).
It is the same location on all VM26/28SS carbs and also the earlier VM28SC.
This passage is always opposite the pilot air passage so it is the innermost or farthest away hole from the outside of the bike and the air screw or blank air screw casting..
i.e at the 4 'o'clock position on the left pair and 8 'o'clock on the right pair.
On some VM26's with the fuel mix screw underneath there are some rogue sets that are made up of all right hand or left hand bodies.
The location for the jets will all be 4 'o'clock or 8 'o'clock depending but in all cases it is the hole farthest away from the blank air screw casting which isn't used on the fuel screw types. 

What is a good jet size starting point for the vm26ss? I have it at .6 to start. Is this just a trial and error situation specific to the tune of the engine? Where have others started? Does one size really fit all?

wrote:

What is a good jet size starting point for the vm26ss? I have it at .6 to start. Is this just a trial and error situation specific to the tune of the engine? Where have others started? Does one size really fit all?

That’s kinda like asking a chief to tell you his secret ingredients in his famous recipe, or asking a magician to tell you how a trick is done. Zed1015 is a thoughtless guy when it comes to helping this forum. But asking him to tell you specific details about an item he sells for a little side scratch is kinda bold. 

He has explained why 5mm and everything that goes with it. 6mm is too large IMO and would leave the venture walls too thin.
Steve

wrote:

What is a good jet size starting point for the vm26ss? I have it at .6 to start. Is this just a trial and error situation specific to the tune of the engine? Where have others started? Does one size really fit all?

Here you will find the answer to your question!!! Why do you don´t trust the experience and knowlegde of zed1015???
Go ride your bike and share your own experience and we will come together here for a brain storming next....

kzrider.com/forum/3-carburetor/608495-78-kz1000-tuning#784083
kzrider.com/forum/13-bike-related/608820...rest-in-these#786684

Ok thanks