Can a VFR750FJ F1 run without a fuel pump? Long story sorry

Hi All

I have seen posts with differing opinions mainly on VF500’s running ok without a fuel pump. Has anyone tried this on an 86 VFR750 F1? Gravity fed that is. I can see it working with a full tank of fuel but not sure what would happen when level drops. My bike was attacked while supposedly in “safe” storage by a tow truck company. When I say attacked I literally mean that! Some manic went nuts on it with a four pound hammer never mind the parts that were stolen of it. My fuel pump was one of the long list of replacements that I have been sourcing over the last two years. A new one is way way out of my budget and a second hand one, well lets just say satin will be ice skating before on comes up at a reasonable price. I by nature am a bit of a stubborn bugger and am determined to get this bike back on the road even if it takes another two years. If anyone interested PM me and I can give you more on the dismal story as well as pictures of what they tried to claim was accident damage.

Cheers,
Wayne

 

Thanks tinkerinWstuff

I did tinker with the idea of using a car solid state pump. You given me a great idea! I'll just add a fuel pump switch with a pilot light. A bit like in aircrafts. Ignition on, pumps on etc....

Thanks
Wayne

 

The same exact Mitsubishi pump was used by many different manufacturers on many models over many years, so breakers' yards should have them.

 

I personally use a universal low pressure pump on my 500 and have never had an issue at all. And as soon as they go bad on my other carbed bikes as well. I also implement a led on the + side of the pump and have it on the gauge cluster so i know that the pump is runnin as well. Just one of my many lil checks cause i have had times when the ig switch went bad on various bikes and the pump wont run either but it will crank and everything else will do what its supposed to. Kust my 2 cents

 

Thanks squirrelman

If what can be termed breakers yards here in Cape Town have more than 200 bikes it's alot. There such demand for fuel pumps that they the first items to be sold. I'd give my left nut to visit a yard like the ones in your pictures

Thanks again,
Wayne

 

Thanks orion3814

Good idea re LED. My bike is Japaness spect so has annoying red light that comes on at 80 km/h I removed the globe but will rewire to fuel pump.

Thanks
Wayne

 

The internal blumbing in the tank for the petcock requires a fuel pump when the fuel level gets close to the pet cock. Will run on gravity if the tank is full if you just want to start it.

 

Here's one, get them to post to SA
HONDA VFR750F-K '89 RC24 FUEL PUMP [G756 | eBay

I did tinker with the idea of bypassing the std tap and its associated internal plumbing and fitting one directly into the fuel level gauge panel at the bottom of the tank. Not sure if it would work but thats how RC30's are however with larger bore petrol pipe.

 

I tried a low pressure facet electric fuel pump on my vfr700. I found even with the electricity cut, the pump remained open. This means gas is always going to the carbs and the bowls would overfill.
My solution was to turn the fuel petcock off when I parked the bike.

I understand there is a style of electric fuel pump that is "positive off" when no electricity is applied but they are not common.

 

Thanks Chuntera, I will look into that cut off makes perfect sence.

Cheers,
Wayne

 

i just put on a mr gasket fuel pump on my bike just now and hit the start button and wow she started right up and its a cold day here at my house and it was only 50$

thank you guys

 

Has anyone tried one of those $28 pumps on ebay for the 90-97 vfr750's? They seem to have a vacuum port on them as well as straight outlets instead of 90* outlets. Other than that, maybe they will work with the 86-89 bikes? The price is certainly right.

 

VFR fuel pump (Mitsubishi-made) is the same as that used on dozens of models by most Japanese manufacturers almost universally from about 1978-until FI.
:congratulatory: Some have angled outlets, others not, but both work if you don't kink the lines. May find minor wiring differences on some pumps, but they all have one wire to +12v power and one to ground.

So finding one in a salvage yard shouldn't be too tuff.
:tranquillity:

Or you could pay China but need to replace it three times more often. :sorrow:



**********

:embarassed:

... to see i forgot i posted on this 3 years ago ! Age-related, no doubt.

 

I fitted a cheap Facet type pump from memory, then I fitted a pressure regulator to control the pressure to 1 PSI and I also fitted a solonoid valve so that when I switch the ignition off the fuel is shutoff so I don't have to bother with the tap, only used for going onto reserve. Too dam easy

 

I know the factory pump does not need a presure regulator nor a positive shut off valve as those are built in the stock pump. I would just like to find a similar function pump that does not require any add-ons. I'm going to keep researching the Caltrex pump I posted a picture of to see if it is a cheap, viable replacement for the 86-89 bikes.

 

I don't know if the pump I fitted needed a pressure regulator and a solonoid valve, I just fitted these for my own satisfaction and peace of mind

 

My first attempt at use a facet pump failed due lack of "positive off...a full tank of gas would flood the carbs when the ignition was off. Last year I got the recommended $48 "postiive off" 3psi pump which appears to have a built-in valve. YMMV

 

Yeah, I know this is an old thread I'm bringing back to life. But, for context, I wanted to tag onto this one, instead of starting a new one.

So, do these carbs have floats and float valves? It seems like they must. If yes, then they should easily hold back the 3ish psi the pump should put out, and so, no flooding should occur. Sometimes these floats/valves go bad, in which case, gravity fed fuel systems will flood too.

I have a 1987 VFR 700 that's missing the fuel pump, and as far as I can tell, it's missing the wiring to the fuel pump, as well. I'm considering just installing a stand-alone pump and wiring, and just using a manual switch every time I ride it. If I hide the switch, it can act as a theft deterrent too.

 

Yes floats and valves, 3-ish PSI. Just a toggle is fine operationally. Just don't cheap out on the pump and stay OEM-ish. A toggle will get you home when a relay fails, but it won't do shit for a cheap pump on Hwy 20 on the way to Winthrop.