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What Drill size Makes 140 Jets?
- testarossa
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1978 KZ1000 A2 Click--->Build Thread
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- jeffasaki
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Lately the only thing making me smile is my bike.
Thanks to all for any input.
Jeff
78 Z1R
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Ontario Canada
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- Motor Head
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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
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- loudhvx
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Hundredths of millimeters is also how the TK jets are sized and is also how the Keihin jets are sized that I've measured. As a matter of fact, even the few Mikuni jets I've measured were sized that way too.
So simple math shows a 140 jet would be 1.4mm or .055". That should be a number 54 bit, according to the chart I just looked up. (Which agrees with Testarosa).
bobmay.astronomy.net/misc/drillchart.htm
Since the hole is already there, and you are really just chasing it with a slightly larger bit, the drilling is very easy on brass jets. I've done dozens and haven't had a single mishap yet (broken bit etc).
Obviously flow rate depends on more than just the diameter of the hole, but if you are comparing same style jets, you really only need the numbers. If you go to a different tyoe of jet, you'll need to adjust the numbers accordingly.
1981 KZ550 D1 gpz.
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- polkat
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- loudhvx
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From this chart bobmay.astronomy.net/misc/drillchart.htmI assume we are talking about the Keihin secondary main jets here. They also use a primary main jet. Anyone know what bit size would come close to a 68 jet?
A #71 bit is a 66 jet.
A #70 bit is a 71 jet.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
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- otakar
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74 Z1-A stock
76 KZ-900 Totaly stock vice MAC pipe
77 KZ-1000A stock
78 Z1-R 100%MINT 500 original Mi.
78 Z1-R Yoshi 1103 kit stage 1 cams Yoshi pipe. Etc
79 KZ-1300 (1400)
80 KZ-1300
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- otakar
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I assume we are talking about the Keihin secondary main jets here. They also use a primary main jet. Anyone know what bit size would come close to a 68 jet?
On a set of BS34s?? I doubt it. :huh: That's what we were talking about. Wasn't it? Or did i miss something? :huh:
74 Z1-A stock
76 KZ-900 Totaly stock vice MAC pipe
77 KZ-1000A stock
78 Z1-R 100%MINT 500 original Mi.
78 Z1-R Yoshi 1103 kit stage 1 cams Yoshi pipe. Etc
79 KZ-1300 (1400)
80 KZ-1300
81 Scratch built GPz1150R
82 KZ1000
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- otakar
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74 Z1-A stock
76 KZ-900 Totaly stock vice MAC pipe
77 KZ-1000A stock
78 Z1-R 100%MINT 500 original Mi.
78 Z1-R Yoshi 1103 kit stage 1 cams Yoshi pipe. Etc
79 KZ-1300 (1400)
80 KZ-1300
81 Scratch built GPz1150R
82 KZ1000
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