Yamaha 4-stroke fuel injector inquiry

[fairdeal]

Boscoe may have a Yamaha document which states the diameter of the holes in a typical 4-stroke fuel injector -
in which case he can tell us and settle the question.

Otherwise - I spent a few minutes photographing one of my 69J-13761-00-00 injectors



and then did some cut and paste.

here's what I have for you guys;

a photo of calipers measuring the tip

and a close-up photo of that tip, clearly enough to see the four "spray holes"

with a graduated scale matching the already established measurement to create a crude "optical comparator".

So - what do you say?

"roughly" - what is the diameter of the hole that sprays fuel?

[99yam40]

I would say close to .2 mm

[fairdeal]

I would say close to .2 mm

That's what I see; IMO 0.25 and maybe 0.3

So 200-300 microns.

[99yam40]

So the 10 micron screens should keep them from plugging up.
or are they 2 micron screens

there should be specs somewhere. but probably hard to come up with that info

[fairdeal]

No one else interested in providing their input?

estimation of size? critique of methodology?

a link or reference to some source for what diameter might be expected?

[pstephens46]

I will guess the diameter is somewhat less than 0.2. Maybe 150 microns. Is that a tiny weld line around the circumference?

[fairdeal]

Is that a tiny weld line around the circumference?

Clearly - impressive, right?

Those Chinese children are amazing....

[rodbolt17]

and the point of this waste of time????

[panasonic]

They are definitely not round holes.

[fairdeal]

and the point of this waste of time????

LOL Good morning Rodbolt - glad to see you are feeling chipper!

So, what do you think of the folks who replace their standard Yamaha water separating filter with a 2 micron filter ?

[boscoe99]

Nothing I can find in what Yamaha data I have provides the diameter of the holes in any fuel injector. It would vary I suspect amongst the various injectors. F350 injectors being the largest all the way down to the F25 EFI model.

The party line at Yamaha is that their ten micron filter is all that is needed. I suspect rodnut will toe the party line. Being the sort of contrarian I am, I used the Racor 2 micron, albeit with a vacuum gauge installed so that I could monitor the status of it, my Merc and then my Yam. Not sure that it saved either from fuel contamination but it never caused a problem.

Injectors are now common every day items. But I still find them and what they do impressive. Open and closing thousand of times a minute, for milliseconds of time, delivering very precise amounts of gasoline at just the right time, while doing it successfully for years and years without a hiccup.

[pstephens46]

They are definitely not round holes.

Is it possible the holes might erode over time? I believe the Fairdeal F225 has over 1700 hours. 45psi is not considered high pressure when compared to some others.

[panasonic]

Is it possible the holes might erode over time? I believe the Fairdeal F225 has over 1700 hours. 45psi is not considered high pressure when compared to some others.

My guess is the spray pattern, they were made like that maybe?The oval shape of the holes are all lined up nicely there.

[dray0151]

and the point of this waste of time????

Knowledge.

[boscoe99]

What could be a greater waste of time than writing a post about other posts being a waste of time?

If rodnut would quit wasting his time posting on waste of time threads then I might be in a better position to overtake his post count when I waste some time posting some useless trivia.

I gotta overtake rodnut so that I can continue my pursuit of 99yam.