PWK vacuum take off for tank tap.

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L.B
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PWK vacuum take off for tank tap.

#1 Post by L.B » Fri Mar 17, 2017 8:30 pm

Has anyone ever used this spigot to take a vacuum off for tank tap? Id like to keep the reserve function.
Its in the same place as the mikuni carbs & seems like it can be drilled through with no issues. Just like to know if anyone else has tried this.
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Bare
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Re: PWK vacuum take off for tank tap.

#2 Post by Bare » Sat Mar 18, 2017 6:28 pm

It IS possible (practical even) to fit a T to one of the oil fittings and use the resulting 'extra' connection for a Vac connection.
Yesss It's been done before and Yess it works 'fine'.

gpaddict
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Re: PWK vacuum take off for tank tap.

#3 Post by gpaddict » Fri Mar 24, 2017 7:37 pm

T in your oil line for vacuum??????
tuned to Paris Hilton specs............rich and retarded!

Bare
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Re: PWK vacuum take off for tank tap.

#4 Post by Bare » Sun Mar 26, 2017 11:45 pm

Was it mistyped!
Buy a cheap plastic T fitting (windshield washer type will do) .
Simply insert it into the oil feed line close to the carb.
2 mins later and you will know if it works.. Or not :smt002

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JonW
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Re: PWK vacuum take off for tank tap.

#5 Post by JonW » Mon Mar 27, 2017 8:37 am

It works, Ive done it before too.
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L.B
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Re: PWK vacuum take off for tank tap.

#6 Post by L.B » Mon Mar 27, 2017 10:17 am

Thanks for the reply bare but wont risk a new build engine worth nearly 3k thanks. Hence why i asked if anyone has drilled a pwk in that spot for vacuum.
One also has to wonder why Yamaha didnt use this method either?
Have emailed Keihin for a def answer.

justind97
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Re: PWK vacuum take off for tank tap.

#7 Post by justind97 » Mon Mar 27, 2017 5:07 pm

What about. Small barb in the reed cage area? We did that for karts

tacky1
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Re: PWK vacuum take off for tank tap.

#8 Post by tacky1 » Tue Mar 28, 2017 12:21 am

This is where I put it on both my 350's, One is running PWK28s and the other is running 34mm flatslides, Works perfect.
I used to run a T off the oil line with the 34,s, I swapped it over, made me fell better.. :)

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yamasukiman
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Re: PWK vacuum take off for tank tap.

#9 Post by yamasukiman » Tue Mar 28, 2017 11:25 pm

Is there not a mod where you can turn the tap into a "on-off" manual tap and do away with the vacuum port?
I'm sure I've seen it on one of the forums.

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JonW
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Re: PWK vacuum take off for tank tap.

#10 Post by JonW » Wed Mar 29, 2017 12:38 am

yes there was a post on it here somewhere, you mod the rubber or plastic bit in the tap to bridge the holes.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

vmxwinn
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Re: PWK vacuum take off for tank tap.

#11 Post by vmxwinn » Wed Mar 29, 2017 2:48 am

I did the exact same as tacky1. It is so easy to just drill a hole in the cross over tube and tap a brass npt/barb in. Not even worth messing with the petcock. Ten minute job at best
85 Y/B, Toomey pipes, PWK 28's, JJH Needle #2, 45 pilot jet, 145 main, Pods, VForce 4 reed blocks, +3 ignition, Milled head 1.1mm squish, R6 Shock, Progressive

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Bare
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Re: PWK vacuum take off for tank tap.

#12 Post by Bare » Fri Apr 21, 2017 12:34 am

Silly answer being : if you can't sus it out.. you don't get to ride :-)

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L.B
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Re: PWK vacuum take off for tank tap.

#13 Post by L.B » Fri Apr 21, 2017 9:57 pm

Well i sorted it out,been for a ride & works fine,simple fix really. Pics soon.

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Re: PWK vacuum take off for tank tap.

#14 Post by L.B » Sat Apr 22, 2017 3:25 am

This mod isn't for everyone,i mainly wanted to retain stock look as much as possible including hoses etc.
So...here we go drilling into brand new 28mm pwk's.
Start with a 3mm drill bit & drill through this spigot/nipple to the intake tube.
Image
Then take a 4mm x .7 plug tap & tap this hole approx 5mm in,drilling through for the vacuum cross drills into this circuit. Its not used as it is an optional bowl vent. There are 2 vent holes & the other side is used so all good.
Image

Then take your 4mm grub screw that has a slight coating of fuel proof thread lock & tighten into place.
Image

Ultrasonic clean carb & blow it out to clear any chips etc from drilling & tapping & you're done. Make sure your thread locker is fuel proof.
Oh,then ride & enjoy.
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JonW
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Re: PWK vacuum take off for tank tap.

#15 Post by JonW » Sat Apr 22, 2017 3:54 am

Great work mate!
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

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