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General Category => General Discussion => Topic started by: arveno on September 04, 2015, 12:42:39 PM

Title: gas tank from carbed bike to EFI bike
Post by: arveno on September 04, 2015, 12:42:39 PM
Hi All ,
could someone explain me how to used a gas tank from a carbed bike to a EFI bike ?
thanks
M.
Title: Re: gas tank from carbed bike to EFI bike
Post by: fotoguzzi on September 04, 2015, 01:01:20 PM
You need to have a return flow to tank, maybe the second petcock will work, ask Rodekyll
Title: Re: gas tank from carbed bike to EFI bike
Post by: rodekyll on September 04, 2015, 01:05:57 PM
If the potseed or early guppy tank, use an external pump and filter.  Pull from the left petcock and put the pressure regulator on the right.  The pressure regulator is already threaded for it.  I don't know about the loop variants.

If the potseed tank, be sure the rear mounting rubbers are set such that the pressure regulator doesn't drag the throttle linkage.
Title: Re: gas tank from carbed bike to EFI bike
Post by: Antietam Classic Cycle on September 04, 2015, 01:08:24 PM
That would depend to a large extent on how the EFI is set up - external pump or pump inside the tank. Early EFI Guzzis used the tank virtually unchanged from the carb bikes before them, facilitated by the pump being external. Fuel was drawn through a petcock on the left in the same location as the carb petcock, though the petcock itself was larger for higher flow. Where the carb bike had a petcock on the right, Guzzi installed the fuel pressure regulator with return line. IIRC, the only other significant change was a larger fuel tank vent hose up near the steering head.
Title: Re: gas tank from carbed bike to EFI bike
Post by: Orange Guzzi on September 04, 2015, 02:42:52 PM
I have a 1984 tank with a left and right petcock outlet.  I used the left outlet to my fuel pump and the right one to the pressure regulator.  The threads work just fine.  I did make a fitting and cap for the fuel level gage.  I welded the threaded piece on the tank by the left outlet, then drilled the hole in the tank, filed and cleaned up.  Made the nut out of a hydraulic hose fitting.  I have posted pictures on W.G. of the parts I used. 
Title: Re: gas tank from carbed bike to EFI bike
Post by: arveno on September 04, 2015, 03:51:23 PM
Thanks everyone for the input , sorry i forgot to mention the bike ( 98 cali ) has external fuel pump.
Regarding the fuel pressure regulator , the original blown so i am using a nissan one .
I re did all the hoses routing and put the new fpr under the seat post... but in case i can always re change the position , not a big deal.

question: is case i do not want to use the factory low fuel sensor, can i just use the traditional fuel petcock with open/close/reserve position ? ( i do not see why not but i am just asking to make sure )

thanks again
Title: Re: gas tank from carbed bike to EFI bike
Post by: rodekyll on September 04, 2015, 04:34:41 PM
In my opinion you can use a traditional petcock, provided you can make the hose work for both the petcock and the pump barb diameters.  Some would say the larger spigot of the efi tanks is needed for enough flow.  If you've ever tried to leak a gallon of fuel out a hole at the rate of 1gal/30 miles you know how little flow is needed. 

ymmv
Title: Re: gas tank from carbed bike to EFI bike
Post by: Orange Guzzi on September 04, 2015, 05:03:19 PM
I have a stock petcock on my tank.  It is on and off only.  No reserve.  The petcock has a filter on the inlet.  Only filter I have in my system.  You can put another petcock in the extra fitting leave it on and run the return fuel from the fpr.  Use f.i. hose and good clamps.  You do not want to blow a fuel line off. 
Title: Re: gas tank from carbed bike to EFI bike
Post by: rodekyll on September 04, 2015, 06:24:39 PM
DO install a fuel filter.  The need is self-evident.
Title: Re: gas tank from carbed bike to EFI bike
Post by: Arizona Wayne on September 04, 2015, 11:28:45 PM
`97 1100 Calis. had EFI with carb gas tank w/conventional pet cocks.  :wink: