Thread size of pilot jets?

[nashville_bill]

Does anyone know the thread size of pilot jets?

I need to run a tap, or screw, or something in the threads where the pilot jets go to clean up the threads. Had to drill out the old ones and some of the threads aren't straight enough to install the new pilot jets. The jets seem to be between 4 and 5 mm at .75 thread. Could they be 4.5 mm or are they not metric at all? If they are 4.5 mm, where would I get a tap or screw?

I will look forward to any suggestions.

[oldnortonrider]

I need these size taps, for my own use.........

Wonder where a set of taps, in this size range, could be gotten?
They'd have to be metric, ..... would be my guess.
May have to rummage around in my batcave; see if I have a screw
the same size.
........ by the way; appreciate your "in detail", explanation, about your "jeweler's work" surgery, as to what all, you did have to do, to get the stubborn pilot jet(s) out.

I'll know more later .

Can't you just imagine, how many of these fine carburetors have been wasted, over the years; because of this one little item .

[Bill]

E-taps.COM

JCarltonRiggs (oldnortonrider) wrote

I need these size taps, for my own use... Wonder where a set of taps, in this size range, could be gotten?

When I was in the midst of "carburetor h*ll" on my GS850L, I thought I was going to need a metric tap for my jammed pilot screws. In an Internet search I found e-taps.com.

They were very customer oriented, replied quickly to my information request and offered fast delivery. In the end I didn't order from them because I was able to extract my pilot screws using an EZ Out.

[oldnortonrider]

Is the above, not, what you're now needing to clean up the pilot jet carburetor threads ?

[Bill]

J Carlton Riggs (oldnortonrider) wrote:

Is the above, not, what you're now needing to clean up the pilot jet carburetor threads

The metric tap would be just the ticket for cleaning up threads after drilling out a jet (as nashville_bill did). In my case, the pilot screws were jammed. I was lucky to be able to get them out without having to drill.

[nashville_bill]

e-taps.com

I looked up e-taps.com and found a 4.5mm X 0.75 tap set for $8 plus shipping. I'm only guessing that it is a 4.5mm because it is between 4 and 5 mm but it beats looking for a set of carbs. They have them in stock and said they will ship today.

Strange businessmen though - they said they will send an invoice with the taps and I can just pay the invoice.

I'll post when I receive the taps and get the jets installed, or not installed.

[nashville_bill]

It turned out to be a 5mm

Well I got the new taps(4.5mm x .75) from e-taps.com and when I tried to clean up the threads with them, I found out that the jets were not that size. When I put the 4.5mm tap in one of the holes, it fell to the bottom of the hole. This scared me because I thought I had drilled out the threads and had ruined the carb. I guess the reason I didn't think it was a 5mm was that some of the old jet threads were still in the holes. To test, I bought a 5mm nut and ran the new jet in it. Why didn't I think of that before I ordered the new taps?

If you ever need to drill out pilot jets:

Use a 1/8" and then a 5/32" drill bit
Use a 5mm x .8 tap(standard 5mm tap)

I bought a cheap set of metric taps from Harbor Freight for $7.99. They are made pretty cheaply but they work and will be very usefull with my old XS11 and XS650.

Well everything turned out great. My 5mm tap, that I had all along, cleaned out all the old jet threads and left enough threads in the carbs to secure the new jets. My bike has great mid range power now. It has a new rear tire but I should probably start shopping for a replacement soon.

[oldnortonrider]

Good news; yes, I'd been waiting to hear the outcome , after you
had "cleaned up" the pilot jet hole.
I think I wuz asleep on that one, myself.
I just put the calipers to a new pilot jet, I have in here; would ya
believe >> IT SED 5MM .
Yer info, on this thread, oughtta be in our manuals.
Of course, a compilation of a bunch of these threads (tips), is a manual in itself.