Jet Size calculator

[QuickMick]

This is a usefull calculator when drilling jet sizes. I figured some people on here could use it too, and maybe put it in the TECH section.

Example, a 140 jet would have a hole dia of .055 which is drill # 54

a 140 jet : 1.40 mm = .055 Dia.
a 115 jet : 1.15 mm = .045 Dia.

This comes in handy when drilling jet sizes instead of purchasing a wad of jets in different sizes.

http://www.worldwidemetric.com/metcal.htm

 

[SuperJETT]

One thing about that, the sizes are approximate, not exact. They are more 'flow equivalents', like a 140 might be 1.4mm true size, but a 135 might not be 1.35mm, though due to the design it flows like it were a 1.35mm.

As long as you're using matching jets (for duals) you're fine.

At least that's how Herb Kane from Mikuni explained it.

 

[Kennay]

Been there, done that, not nearly as accurate. Just buy the jets.

 

[#ZERO]

Don't drill your jets you're just asking for trouble. :spank:

Jet-World has Mikuni jets for $2.09 each. http://www.jet-world.net/partsacc/carbsintake.asp

 

[keefer]

Don't drill your jets you're just asking for trouble. :spank:

Jet-World has Mikuni jets for $2.09 each. http://www.jet-world.net/partsacc/carbsintake.asp

Thats the advice I have always gotten from several different sources. Drilling is not the best way to change jet sizes. Just buy new IMO.

 

[sflsurfrider]

One thing about that, the sizes are approximate, not exact. They are more 'flow equivalents', like a 140 might be 1.4mm true size, but a 135 might not be 1.35mm, though due to the design it flows like it were a 1.35mm.

As long as you're using matching jets (for duals) you're fine.

At least that's how Herb Kane from Mikuni explained it.

why does that sound like a 'drug pusher' from miami vice?

 

[Matt_E]

Seems like they are better ways to save money than on the $2 parts that accurately measure fuel flow :dunno:

 

[Motorheads5]

That technology was for the old sb carb's with non replaceble jet's once again kawi pioneered it's way into history lol uh oh hear goes

 

[keefer]

Yep, I remember getting a numbered drill size to enlarge the fixed jetting on the round body Mikuni after I installed my big ole Coffmans half pipe and Mariner high comp head on my 550. Those were the days,

 

[QuickMick]

I guess that goes up with whats best, which oil to use, gaskets, brand, motor builder, pistons, plugs, bars, battery, turf, hand pole... to each his own.

Riva has jets for 2.00 each. Drilling was only a option.

 

[JonnyB]

I guess that goes up with whats best, which oil to use, gaskets, brand, motor builder, pistons, plugs, bars, battery, turf, hand pole... to each his own.

Riva has jets for 2.00 each. Drilling was only a option.

Mick I thank-you! I know in the past I bought a bunch of jets just to find the starting point for fine tuning.

 

[Polish jet pilot]

Yep, I remember getting a numbered drill size to enlarge the fixed jetting on the round body Mikuni after I installed my big ole Coffmans half pipe and Mariner high comp head on my 550. Those were the days,

hat you talking about?? Did that just a year ago Kawis still there!
Andrew (SJ convert)