jets wanted

[Wayne Kerr]

The formula is ,,,, 25.4 / 1000 x required jet size = mm.
Thus, 25.4 / 1000 = 0.0254. 0.0254 x 86 = 2.18mm drill.
Piece of piss, as I said.

[Wayne Kerr]

Originally posted by karl
i.v got a set of 74 's look like ill drill them out

Exactly what I've done, easy peasey!

[michaelcaine]

if im getting this wrong then im sorry but are you saying a 0.86 jet = a whole size of 2.18 mm?

[Wayne Kerr]

Originally posted by michaelcaine
if im getting this wrong then im sorry but are you saying a 0.86 jet = a whole size of 2.18 mm?

Yup!

[michaelcaine]

id check again then because theres no way the hole in my 0.86 jets was 2mm ,but like i said i might be getting the wrong end of the stick

[Wayne Kerr]

Originally posted by michaelcaine
id check again then because theres no way the hole in my 0.86 jets was 2mm ,but like i said i might be getting the wrong end of the stick

It's not 0.86, thats just short of an inch!!!!! It's 086 (thou)!
What size was it?

[michaelcaine]

alot smaller than 2mm,more like 1mm or under

[Wayne Kerr]

Originally posted by michaelcaine
alot smaller than 2mm,more like 1mm or under

Then they ain't 086's. You looking at the right ones ????

[michaelcaine]

believe me after the greif i had getting them i did check the size,its stamped on them,genuine merc ones,if the hole is too big when you drill them it will just run too rich so no harm done,only to the jets give it a go

[Wayne Kerr]

Originally posted by michaelcaine
believe me after the greif i had getting them i did check the size,its stamped on them,genuine merc ones,if the hole is too big when you drill them it will just run too rich so no harm done,only to the jets give it a go

Right then ,,,,,,,, if they're genuine Merc ones, no problem!
Did you measure the hole size? Are your eyes suggesting that the hole is less than 1mm? Check the formula!
If your happy with the way it runs, that's what it's all about. If your doing 16 gallons an hour don't tell the Bank Manager you've got a boat!

Karl, hope your taking all this in! Bonjour!

[karl]

Originally posted by Wayne Kerr
Right then ,,,,,,,, if they're genuine Merc ones, no problem!
Did you measure the hole size? Are your eyes suggesting that the hole is less than 1mm? Check the formula!
If your happy with the way it runs, that's what it's all about. If your doing 16 gallons an hour don't tell the Bank Manager you've got a boat!

Karl, hope your taking all this in! Bonjour!

im lost

[Wayne Kerr]

Originally posted by karl
im lost

Read it slow mate, it'll come to you. If your still confused PM me with your number and I'll talk you through it, no problem.

Back from LM on Tuesday.

[karl]

Originally posted by Wayne Kerr
Read it slow mate, it'll come to you. If your still confused PM me with your number and I'll talk you through it, no problem.

Back from LM on Tuesday.

thank mate think iv got it

[JamesM]

25.4mm (thats 1 inch) x 0.086 = 2.1844mm

Just like matey said, easy!!!

It must just a trick of the eye the fact that they dont look that big.
If you had told me my 78's were 1.98mm diameter I would have said that bollox untill I measured or calculated it.

As Matt said though just running the correct sized drill through isn't necasarily going to get them to the size or flow rate you want. If it were me I'd take them to a decent machine shop, tell them what size and bore finish I wanted and let them worry about the how to.

[BluFin]

a quick ball park way of checking is to get some known size dirlls & use the plain shank as go / no-go for sizing. fairly cheap effective way with a reduction in measurement error.
If you are going to open them up a mill & decent reamer to finish. not a £6.50 draper jobbie

[Burty]

Personally i wouldn't risk it, too much chance of it going wrong.
you will never get 2 the same,

firstly can get 86 thou imperial drill bit? i doubt it
can you get a 2.18mm drill bit? that actually makes a 2.18mm hole?
they aren't just a hole in the middle they have the edges reamed
what about burrs?
what if the drill wanders?

its just not worth it.

[JamesM]

Originally posted by Johnny Boat Dude
If it were me I'd take them to a decent machine shop, tell them what size and bore finish I wanted and let them worry about the how to.

[Matt]

That was my point early on. They're such a precision part that the smallest deviation or imperfection can be significant.
A 2.18 drill, I think, measures 2.18 mm. It doesn't drill a 2.18 mm hole, and the hole certainly isn't clean.