power jet carb in action!

repherence2
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power jet carb in action! Mar 10, 2021 21:09:22 GMT -5 90GTVert, 190mech, and 2 more like this

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Post by repherence2 on Mar 10, 2021 21:09:22 GMT -5

i came across this vid on YT and i thought it might be helpful for others that are trying to tune PWK carbs that have power jets. i thought i was neat stuff. pretty neat to see when the vacuum pulls the fuel up to the power jet. i liked mauibird's vid of his OKO in action during a moped cruise, but his did not have the power jet.

Ningbo GTX (10" wheels). 90cc block, 54mm Taida aluminum/nicasil bore (ported). YMS V8 sectional pipe. Polini clutch bell 107mm. Stage 6 Racing clutch Red (stiffest)springs. NCY yellow contra spring & ball bearing torsion controller. Malossi primary gear (41 X 15). CT intake manifold. OKO 28mm carb (8 hole emulsion tube, 127 main, 45 slow). Malossi 788 belt. KELI variator. Motoforce rollers 4.0g. Big brake rotor kit. TTO Tach & temp guages. Michelin S1 90/90x10 tires.

FrankenMech
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power jet carb in action! Mar 11, 2021 5:36:32 GMT -5 repherence2 likes this

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Post by FrankenMech on Mar 11, 2021 5:36:32 GMT -5

My Vito power jet works a little differently. It has a sensor jet that extends into the airflow so it senses airflow as well as vacuum. It is adjustable.
www.vitosperformance.com/product/vitos-performance-power-jet-valve-adjustable-powervalve-keihin-mikuni-pjk

-Mac
71/100+ yr OLD Engineer. Certified Lunatic with CRS. Never PC.
Tired, Deaf, Weak, Blind, Worn out, and Stupid.
Delete Facebook and Twitter-X.
2012DongFang POS 50cc4T Ruck-style Reverse Trike w/2 front TIRES:)

repherence2
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power jet carb in action! Mar 11, 2021 9:48:52 GMT -5 via mobile

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Post by repherence2 on Mar 11, 2021 9:48:52 GMT -5

Mar 11, 2021 5:36:32 GMT -5 FrankenMech said:

My Vito power jet works a little differently. It has a sensor jet that extends into the airflow so it senses airflow as well as vacuum. It is adjustable.
www.vitosperformance.com/product/vitos-performance-power-jet-valve-adjustable-powervalve-keihin-mikuni-pjk

Thanks for pointing that out as well as the link.

I seen pics of that syle of power jet valve on Richstalordporting when i was researching venturri dividers. I always wanted to see how a power jet like that responds with venturri dividers.

Ningbo GTX (10" wheels). 90cc block, 54mm Taida aluminum/nicasil bore (ported). YMS V8 sectional pipe. Polini clutch bell 107mm. Stage 6 Racing clutch Red (stiffest)springs. NCY yellow contra spring & ball bearing torsion controller. Malossi primary gear (41 X 15). CT intake manifold. OKO 28mm carb (8 hole emulsion tube, 127 main, 45 slow). Malossi 788 belt. KELI variator. Motoforce rollers 4.0g. Big brake rotor kit. TTO Tach & temp guages. Michelin S1 90/90x10 tires.

aeroxbud Scoot Legend! Posts: 13,720 Location: Portsmouth U.K.	power jet carb in action! Mar 16, 2021 6:05:25 GMT -5 repherence2 likes this Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by aeroxbud on Mar 16, 2021 6:05:25 GMT -5 Shiny red did a nice video on the 30mm Dellorto too.
	Yamaha Aerox NS50 2016 project Yamaha Aerox NS50 2016 Piaggio Typhoon 2019: Great scooter, poorly built (sold) Yamaha Slider 2002: The problem child (sold) Yamaha BWS NG: The Family affair (son now owns) Yamaha Aerox YQ50 2008: The fast one (sold) Yamaha Jog RR 2004: The first one (sold) Mrs Bud 10/06/22 you are not going to pull that engine apart and put lots of new bits in it, are you?

captincvmn Scoot Pro 2023 Scoot Tag Champ Marginally more time, weather is definately worse Posts: 2,314 Location: Dover, PA	power jet carb in action! Mar 16, 2021 8:04:34 GMT -5 via mobile repherence2 likes this Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by captincvmn on Mar 16, 2021 8:04:34 GMT -5 I’m surprised by how much shit blows outwards
	The journey of a thousand miles begins with a dead battery Really just Rob, Captincvmn is my ancient AOL name ‘08 Keeway F-act modded with 70cc (Naraku-killed, Stage6 Street Race-killed) Polini Corsa cylinder, 19mm ChinaDellorto, straight groove torque driver, aftermarket speedo and Giannelli pipe June of ‘23 Got a 2008 Moto Guzzi Norge now I’m splitting time.

FrankenMech
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power jet carb in action! Mar 16, 2021 8:27:55 GMT -5 aeroxbud, repherence2, and 1 more like this

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Post by FrankenMech on Mar 16, 2021 8:27:55 GMT -5

Single cylinder engines are like that. Fuel/air mix gets pulled in then valves close and mix bounces back. When there are multiple cylinders it does not happen as much. When valves don't close completely and there is a flame path back it gets exciting. I think that part of the function of the air filter box is to capture the blowback and use it to gain efficiency as well as muffle sound.

Last Edit: Mar 16, 2021 8:30:40 GMT -5 by FrankenMech

-Mac
71/100+ yr OLD Engineer. Certified Lunatic with CRS. Never PC.
Tired, Deaf, Weak, Blind, Worn out, and Stupid.
Delete Facebook and Twitter-X.
2012DongFang POS 50cc4T Ruck-style Reverse Trike w/2 front TIRES:)

captincvmn Scoot Pro 2023 Scoot Tag Champ Marginally more time, weather is definately worse Posts: 2,314 Location: Dover, PA	power jet carb in action! Mar 16, 2021 9:07:11 GMT -5 via mobile Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by captincvmn on Mar 16, 2021 9:07:11 GMT -5 Run a reed valve on the exterior of the carb also? Wonder how bad that would cramp the intake stream.
	The journey of a thousand miles begins with a dead battery Really just Rob, Captincvmn is my ancient AOL name ‘08 Keeway F-act modded with 70cc (Naraku-killed, Stage6 Street Race-killed) Polini Corsa cylinder, 19mm ChinaDellorto, straight groove torque driver, aftermarket speedo and Giannelli pipe June of ‘23 Got a 2008 Moto Guzzi Norge now I’m splitting time.

FrankenMech Scoot Master! Grow a Brain, -Avoid Social Media Posts: 8,219 Location: KC Metro, KS	power jet carb in action! Mar 16, 2021 10:23:55 GMT -5 repherence2 and captincvmn like this Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by FrankenMech on Mar 16, 2021 10:23:55 GMT -5 Like running a choke ON all the time.
	-Mac 71/100+ yr OLD Engineer. Certified Lunatic with CRS. Never PC. Tired, Deaf, Weak, Blind, Worn out, and Stupid. Delete Facebook and Twitter-X. 2012DongFang POS 50cc4T Ruck-style Reverse Trike w/2 front TIRES:)

repherence2
Scoot Pro

Posts: 1,494

power jet carb in action! Mar 18, 2021 0:19:38 GMT -5 aeroxbud likes this

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Post by repherence2 on Mar 18, 2021 0:19:38 GMT -5

Mar 11, 2021 5:36:32 GMT -5 FrankenMech said:

My Vito power jet works a little differently. It has a sensor jet that extends into the airflow so it senses airflow as well as vacuum. It is adjustable.
www.vitosperformance.com/product/vitos-performance-power-jet-valve-adjustable-powervalve-keihin-mikuni-pjk

how's this PWK power jet...transparent Bowl! eebay action.

sounds like some 4 stroke Filipino action.

Ningbo GTX (10" wheels). 90cc block, 54mm Taida aluminum/nicasil bore (ported). YMS V8 sectional pipe. Polini clutch bell 107mm. Stage 6 Racing clutch Red (stiffest)springs. NCY yellow contra spring & ball bearing torsion controller. Malossi primary gear (41 X 15). CT intake manifold. OKO 28mm carb (8 hole emulsion tube, 127 main, 45 slow). Malossi 788 belt. KELI variator. Motoforce rollers 4.0g. Big brake rotor kit. TTO Tach & temp guages. Michelin S1 90/90x10 tires.

FrankenMech Scoot Master! Grow a Brain, -Avoid Social Media Posts: 8,219 Location: KC Metro, KS	power jet carb in action! Mar 18, 2021 1:51:57 GMT -5 repherence2 likes this Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by FrankenMech on Mar 18, 2021 1:51:57 GMT -5 One can add more fuel by changing the taper of the main jet needle to flow more fuel at high vacuum. Some large vehicle carbs do this by using a power valve or metering rods.
	Last Edit: Mar 18, 2021 1:53:07 GMT -5 by FrankenMech -Mac 71/100+ yr OLD Engineer. Certified Lunatic with CRS. Never PC. Tired, Deaf, Weak, Blind, Worn out, and Stupid. Delete Facebook and Twitter-X. 2012DongFang POS 50cc4T Ruck-style Reverse Trike w/2 front TIRES:)