Vac signal for Zx fuel pump location

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1man8scoots
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Re: Vac signal for Zx fuel pump location

Post by 1man8scoots »

Ask Alex what he did about his issue he was having.
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Re: Vac signal for Zx fuel pump location

Post by tru72 »

If your going to put a vacuum on your manifold it needs to be under the reed cage . The reason why those pumps don't work on a regular vacuum location is because it's need a pulse , not a constant pull.
That's why they are tapped into the crankcase. Easy test try suck on that vacuum on that pump , it will won't let any gas thru , only when you release the vacuum it will spurt lol.
That's why it's called a pump not a petcock
D
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Re: Vac signal for Zx fuel pump location

Post by Wheelman-111 »

Greetings:

SO: The fuel pressure with the pump is much higher than the Polini float needle mechanism - which is designed one presumes for gravity feed - can withstand? THe first thing I'd suggest is a new needle or needle + seat in that Polini carb. Next, see if you can get some idea of the pressure that pump puts out. Modern automotive fuel systems have valve that opens when the pressure exceeds a preset limit. Perhaps there's a way to plumb in an adjustable valve to relieve that pressure - rerouting it to the tank perhaps? You may have to look into how modern fuel-injected bikes manage the pressures. I'm certain the components are out there, but you'll be plowing new ground adapting it to the humble AF series.
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Re: Vac signal for Zx fuel pump location

Post by sanjuro »

Ditch the carb and try another one.
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Re: Vac signal for Zx fuel pump location

Post by bonesv »

graphite9 wrote:The thing is, TONS of guys are running this same setup, all over the world, without a complex system. just need to find out how. Some guys are telling me it works perfect from manifold, others say it has to be from block.
Wow, these Dio's fun. I don't understand how the fuel pump is good on a stock carb but not on a pwk?
It must have to do with the extra displacement in the case pressure......
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paulpauly7
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Re: Vac signal for Zx fuel pump location

Post by paulpauly7 »

Ive seen a few here and no one had over fueling issues .Most are running oko carbs not polini .It has to be a carb issue
86 Nifty Fifty (spree)
ZX disk brake
Kitico 120kmh speedo
AF18 ZX ported
Polini corsa
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Re: Vac signal for Zx fuel pump location

Post by Dakine »

So this is why I see alot of Super dios with Sym Blocks.. Lol is this reall why? Since theres the vacuum by the oil plug on the block?
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Re: Vac signal for Zx fuel pump location

Post by Dakine »

Possibly. But the vacuum nipple is kind of in a different spot if someone really wanted to be technical lol. That cant be the difference/Issue though.
When I had my Super Dio we just put a nipple on the bottom of the Ct manifold. We ran a small stroker motor and a 72cc motor (Different blocks) but used the same manifold and it seemed to run fine.
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Re: Vac signal for Zx fuel pump location

Post by veedubh20 »

stroka motor too much power :surprise: :naughty:
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Re: Vac signal for Zx fuel pump location

Post by Wheelman-111 »

Greetings:

What type of Technical Jargon is this "Messing" of which you speak? Break it down into terms feeble-minded Wheelman is apt to understand please. Unless you measure the PSI output of the fuel pump and the Fail pressure of the float valve, you're guessing. Sometimes guessing is OK.
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Re: Vac signal for Zx fuel pump location

Post by 1man8scoots »

You can do it!
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Re: Vac signal for Zx fuel pump location

Post by 1man8scoots »

You have to adjust for the squish of the float needle valve. Sometimes if you adjust the float to lean it will stop the over flow. If it doesn't stop swap out the needle valve and see how it goes.
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Re: Vac signal for Zx fuel pump location

Post by paulpauly7 »

Wow this is getting intense now .Im sorry i have no more input for you.
86 Nifty Fifty (spree)
ZX disk brake
Kitico 120kmh speedo
AF18 ZX ported
Polini corsa
Malossi crank
CTmani
24mmOKO
40pilot118main
Scorpion pipe
8.44 to 1
Michelin s1
71.3mph
92 yz125, 94 crm250
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bonesv
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Re: Vac signal for Zx fuel pump location

Post by bonesv »

Is the fuel pump oem? or aftermarket?
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S4Patrick
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Re: Vac signal for Zx fuel pump location

Post by S4Patrick »

VERY nice work.....how about a couple pictures of the FPR and of the FPR installed....name/ info on the FPR?

What carb did you wind up using with the FPR?
'87 Aero 50 STOCK (only 350miles)
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'86 Aero (AF16 Corsa-SEF Black-OKO21mm-8.44)
'98 Live Dio ZX - 50th Anniversary Edition 68cc
'92 Super Dio ZX - AF18 Corsa

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