Pilot Jet Hole - Is it a really small thru hole?

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Tempest
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Location: Horley (Near Gatwick Airport)

Pilot Jet Hole - Is it a really small thru hole?

Post by Tempest »

Been cleaning my carbs tonight, Jet's out, and using carb cleaner (not sure how aggressive the cleaner is, but think it's an ok one)

Jet's had a fair bit of gritty bits over them, and some surface dirt, been using various methods to remove it and clear holes.
I thought the carb cleaner would burn thru it, but seems some manual effort is required also.

My question is about the Pilot Jets.

The main jet and the emulsion tube, when you look thru them, have a quit large and clear hold running up the middle of them.

the pilot jet however, initially I thought was blocked, but with some blowing and cleaning I was able to see a very very fine spec of light thru them.

Is this normal?

they have a large thru hole at either end, but is it right that there is only a very VERY fine (way less than a pin size) hole actually in the very middle of them?
Just a fine spec of light?
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8541Hawk
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Re: Pilot Jet Hole - Is it a really small thru hole?

Post by 8541Hawk »

There are actually 3 small holes inside the 1 hole you can see.

Also the emulsion tubes are different front to rear. If you have mixed them up, there is a pic that shows where they should go.
Loud pipes don't save lives, knowing how to ride your bike will save your life.
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Tempest
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Re: Pilot Jet Hole - Is it a really small thru hole?

Post by Tempest »

8541Hawk wrote:There are actually 3 small holes inside the 1 hole you can see.

Also the emulsion tubes are different front to rear. If you have mixed them up, there is a pic that shows where they should go.
I've been careful and they are in pots, with numbers on and kept both bits on their respective sides (pots) at all times.

I took a photo right away before starting to clean them:

Image

The pilot jet on the right.
Just to clarify, in case there is some misunderstanding with what I'm asking.
I don't mean the holes in the side of the tube. I mean the hole that runs thru the centre (like looking thru a telescope)

The other two (left two) in this photo have large openings all the way thru them, the pilot jet, on the right has a tiny tiny spec of a hole. I'm not sure is this is right or it's blocked?
Is the thru hole on the pilot jet supposed to be large (when I say large, I mean about 2mm) at either end, then, in the middle it's only a tiny tiny hole?
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8541Hawk
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Re: Pilot Jet Hole - Is it a really small thru hole?

Post by 8541Hawk »

Then you are in good shape.
Also yes I did mean the pilot jet not the emulsion tube when I said there are 3 small holes in there.
If you look down the small hole in the pilot jet, there are 3 smaller holes that actually meter the fuel.
That is why pilots are so hard to get clean. :thumbup:
Loud pipes don't save lives, knowing how to ride your bike will save your life.
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Tempest
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Re: Pilot Jet Hole - Is it a really small thru hole?

Post by Tempest »

8541Hawk wrote:Then you are in good shape.
Also yes I did mean the pilot jet not the emulsion tube when I said there are 3 small holes in there.
If you look down the small hole in the pilot jet, there are 3 smaller holes that actually meter the fuel.
That is why pilots are so hard to get clean. :thumbup:
Really?
Amazing.

Given the larger holes in the brass pilot jet are only around 2mm in dia (bit of a guess) at either end, but there is a little bit of solid in the middle of the brass, to have 3 holes thru that solid bit is pretty amazing, they must only be fractions of a milimeter in dia. will have to take to work and look under magnification to see if I can see these 3 holes you mention as I can only see one when I look down the brass pilot jet.
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