Fuel Pump tap breaks off

[Psychler62]

This revives the following, because I've done the same thing:

So I broke this fuel fitting off�.
« on: March 05, 2012, 05:17:55 PM »

Don't even ask about ordering the red elbow tap, which is NOT A PART, but considered by Guzzi to be integral to a $750 fuel pump assembly. Thanks, Guzzi.

I removed the offending tap/petcock and was left staring at an unthreaded port, one inch deep, about 9/16" in diameter.






bulk image hosting


I reamed/tapped it to 5/8" npt, since no petcock on Earth is 9/16" and I figure 5/8" gets me closer to the plumbing and petcock mainstream.

After much searching at the hardware store and on-line, I think I have a somewhat elegant and simple solution.

I propose to step this port size down to 1/4" via a 5/8"-to-1/2" barrel adjuster (firearms industry, fyi)
Then a conventional 1/2"-to-1/4" reducing connector
Then a 1/4" by 1/8" 90-degree elbow OR a mini petcock valve with a 90-degree outlet to a 1/4" hose line
Thence, to a quick-connect with the main fuel line.

It all has to be compact, fyi

Here's the hardware. Please offer suggestions/critiques/derisive laughter/sympathy/judgment, etc. Apologies that you may have to click on each one to see them better.

1. Two-part stepdown to 1/4"




2. The turn (see below for a petcock valve alternative):




3. Outlet toward fuel line:




Quick-Connect:





bb code


Alternative two/mini-petcock instead of an elbow:




upload pictures


The filter inserts on most petcocks are far too long to fit in this 1" depth hole, and I don't think I need one, anyway.
First, because this is not a true petcock that anyone will be turning on/off/reserve, since it's unreachable.
Second, there already is a filter upstream on the immersed fuel pump.
Third, I can add an in-line fuel pump downstream, between the tank and the splitter, if anyone thinks I need it.

Ideas?

(If this works, I may assemble a few of them and offer them up. A few folks have posted on this break)

[fotoguzzi]

stupid design..


great research.. what bike is that on?  note to self.. don't buy one..

[Kiwi Dave]

This revives the following, because I've done the same thing:

So I broke this fuel fitting off on: March 05, 2012, 05:17:55 PM

Don't even ask about ordering the red elbow tap, which is NOT A PART, but considered by Guzzi to be integral to a $750 fuel pump assembly. Thanks, Guzzi.

I understand this will fit.  Fuel spigot Aprilia AP8104192, for a Pegaso 650 IE

If you search the part number, the pictures certainly look like it will work.

[pete roper]

Yes, it's a stupid design. Yes the Pegaso part is available and works.

Pete

[antmanbee]

There is this part made of aluminum.

https://ziptyracing.com/products/fuel-pump-elbow-oem-8000ah2930-gte-fi-husky

[guzzisteve]

That looks to be the hot s**t !!!

[Nick]

or you can go here   http://www.gutsibits.co.uk/pr/TheShop/index.php?q=fuel+pump+&f=d&Model=2&search=SEARCH

and search for Fuel Pump Spigot FUA30000 and you'll see this



The cost was less than $30 when I got it.
Great service from the Gutsibits guys!

[rodekyll]

My drugs are better than your drugs.   

I like everythinng about it except the complexity, size, and expense.  If you're going to hog out the bulkhead plate, why not put in an AN barb of the best size, put a hose on it, and put a marine fuel tank quick coupler on the hose?  Simple, direct, moves the release point to anaccessible place, and eliminates a lot of future frustration.

$0.02

[Orange Guzzi]

Look at hydraulic hose fitting at McMaster Carr web site.  They have sae threads and come in various configurations.  I have cut the end off that I needed and then welded it onto a tank.  I used a male p.t. x female p.t. fitting, cut in half and welded just the male  end onto a tank for a nipple too thread a petcock on.  They come in all types of threads.  I found one the matched the thread size for a Moto Guzzi petcock, fuel pump line and pressure by-pass valve. 

http://www.mcmaster.com/?orderview=new#standard-hydraulic-hose-fittings/=15umv9d

http://www.mcmaster.com/?orderview=new#standard-hydraulic-hose-fittings/=15umvn5

Couple of examples.  Cut off the part you need and toss the rest.  Have someone TIG weld it to the plate. 

[RinkRat II]

Greetings, My only concern on this exercise would be to keep the diameter of the fittings as large as possible  especially if this bike is fuel injected. Minimum I.D. should be kept at least 5/16. Good Luck

    Paul B

[Psychler62]

stupid design..


great research.. what bike is that on?  note to self.. don't buy one..

Aguila Nera, 2011. Otherwise a pretty cool bike, and relatively rare.

[Psychler62]

There is this part made of aluminum.

https://ziptyracing.com/products/fuel-pump-elbow-oem-8000ah2930-gte-fi-husky

Damn. That looks perfect --- If I hadn't already threaded the port. 

[Psychler62]

or you can go here   http://www.gutsibits.co.uk/pr/TheShop/index.php?q=fuel+pump+&f=d&Model=2&search=SEARCH

and search for Fuel Pump Spigot FUA30000 and you'll see this



The cost was less than $30 when I got it.
Great service from the Gutsibits guys!

This whole experience has made me wary of plastic, and wary of something affixed so "permanently" as that plastic one.

[sib]

Greetings, My only concern on this exercise would be to keep the diameter of the fittings as large as possible  especially if this bike is fuel injected. Minimum I.D. should be kept at least 5/16. Good Luck

    Paul B

I can't understand the logic of that.  Flow rate is what should determine the diameter, not pressure.  I can't see why the fuel flow rate would be higher with fuel injection vs carburation.

[Psychler62]

My drugs are better than your drugs.   

I like everythinng about it except the complexity, size, and expense.  If you're going to hog out the bulkhead plate, why not put in an AN barb of the best size, put a hose on it, and put a marine fuel tank quick coupler on the hose?  Simple, direct, moves the release point to anaccessible place, and eliminates a lot of future frustration.

$0.02

Short answer is I can't find much of any type coupling that goes directly from 5/8 to the appropriate hose size. That was my first search.

 

[Psychler62]

Look at hydraulic hose fitting at McMaster Carr web site.  They have sae threads and come in various configurations.  I have cut the end off that I needed and then welded it onto a tank.  I used a male p.t. x female p.t. fitting, cut in half and welded just the male  end onto a tank for a nipple too thread a petcock on.  They come in all types of threads.  I found one the matched the thread size for a Moto Guzzi petcock, fuel pump line and pressure by-pass valve. 

http://www.mcmaster.com/?orderview=new#standard-hydraulic-hose-fittings/=15umv9d

http://www.mcmaster.com/?orderview=new#standard-hydraulic-hose-fittings/=15umvn5

Couple of examples.  Cut off the part you need and toss the rest.  Have someone TIG weld it to the plate.


I'll try this option if my own garage skills fall short. I'm trying to fix it without having to take it to a machine shop. I don't weld.

[rodekyll]

I can't understand the logic of that.  Flow rate is what should determine the diameter, not pressure.  I can't see why the fuel flow rate would be higher with fuel injection vs carburation.

An efi system circulates many liters/minute.  Bosch wants a 10mm (3/8 )hose on the upstream side.  Else the pump suffers and you get this needy, moaning sound out of it.

[Nick]

This whole experience has made me wary of plastic, and wary of something affixed so "permanently" as that plastic one.

Not much to be wary about really. I just installed this  http://www.beemerboneyard.com/cpcqkdiscon1.html in a more accessible location, and would never need to touch the elbow again. Worked great for my EV.
Just my

[tris]

I'm sure I read somewhere that there is a Ford part that is exactly the same.

[ITSec]

An efi system circulates many liters/minute.  Bosch wants a 10mm (3/8 )hose on the upstream side.  Else the pump suffers and you get this needy, moaning sound out of it.

This may differ on other bikes, but the CARCs and others that use a similar design do all the circulation on the system inside the tank; the portion outside is what used to be called the 'high-pressure rail' side and no return circulation occurs from outside the tank. That being said, I do believe a good-sized diameter is appropriate for all parts (hose and fittings) used for delivery to the injectors. I would discourage using any parts with a diameter smaller than the factory configuration.

For other readers, the fuel injection system is based on a concept of a constant and consistent level of pressure within the supply to the injectors, and the flow determined by the amount of time the injectors are held open. In other words, the pressure cannot be allowed to drop (or unreasonably increase) even though the flow rate may need to quickly increase (or suddenly decrease). To achieve this, the available flow rate from the pump needs to be higher than the maximum delivery requirement, and then be 'throttled back' by the pressure valve - acting almost in the same manner as a wastegate in a turbocharger.

[malik]

or you can go here   http://www.gutsibits.co.uk/pr/TheShop/index.php?q=fuel+pump+&f=d&Model=2&search=SEARCH

and search for Fuel Pump Spigot FUA30000 and you'll see this



Note that this elbow is also sold by TLM as a Breva 750 part.
The cost was less than $30 when I got it.
Great service from the Gutsibits guys!

[sib]

An efi system circulates many liters/minute.  Bosch wants a 10mm (3/8 )hose on the upstream side.  Else the pump suffers and you get this needy, moaning sound out of it.

As has been pointed out, that's not the way the EFI system works on Guzzis.

The way I see it is, let's say your bike gets 30 mpg (most get more).  That means that at 60 mph, it consumes 2 gal/hour.  That comes to 2/3600 gal/sec = 0.2 ml/sec, not much of a flow.  Even allowing for more consumption during acceleration, I doubt that such low flows would have any trouble getting through a 1/4 inch (or smaller) diameter hose without a significant pressure drop.

[rodekyll]

Yup, you're right.  I forgot the internal pump part.  Sorry.

[ITSec]

As has been pointed out, that's not the way the EFI system works on Guzzis.

The way I see it is, let's say your bike gets 30 mpg (most get more).  That means that at 60 mph, it consumes 2 gal/hour.  That comes to 2/3600 gal/sec = 0.2 ml/sec, not much of a flow.  Even allowing for more consumption during acceleration, I doubt that such low flows would have any trouble getting through a 1/4 inch (or smaller) diameter hose without a significant pressure drop.

Generally true, but during rapid acceleration the mileage drops pretty dramatically and the flow rate increases correspondingly - you have to allow for quite a lot of variation. There's no good reason to reduce the available diameter since the parts, even for an aftermarket fix, allow the stock specs to be maintained.

[RinkRat II]

I can't understand the logic of that.  Flow rate is what should determine the diameter, not pressure.  I can't see why the fuel flow rate would be higher with fuel injection vs carburation.

  Carburetors utilize gravity and atmospheric pressure to fill the fuel bowl so the carb can atomize the fuel under intake vacuum conditions . Even in automotive use a fuel pump only produces 7 to 9 psi. With fuel injection, the injectors are rated in pounds per hour and the pump and pressure regulator are sized for that and putting a restriction or reducing the line going to the injectors could cause leaner than designed conditions.  Real world use has to factor sea level to high altitude  and  heavy acceleration  to cruising to cover all bases to prevent failure. Reducing the fuel supply fittings inside diameter  not worth the risk.

   Paul B

[pauldaytona]

Since the pump in tank at guzzi, mostly only one line comes out, that is regulated at 3 bar. The line doesn't need to be that wide to get it trough.
Before that, the pump/filter/pressure valve was external and then they made a large diameter line from tank to filter/pump. 

[Rough Edge racing]

  Carburetors utilize gravity and atmospheric pressure to fill the fuel bowl so the carb can atomize the fuel under intake vacuum conditions . Even in automotive use a fuel pump only produces 7 to 9 psi. With fuel injection, the injectors are rated in pounds per hour and the pump and pressure regulator are sized for that and putting a restriction or reducing the line going to the injectors could cause leaner than designed conditions.  Real world use has to factor sea level to high altitude  and  heavy acceleration  to cruising to cover all bases to prevent failure. Reducing the fuel supply fittings inside diameter  not worth the risk.

   Paul B

 Four stroke engines at wide open throttle and maximum power use 1/2 pound of gas per hour per HP, or about  one gallon for 14 HP...This varies slightly depending on engine design but whether injected or carburetor, the fuel required to support the power is about the same..

[John A]

I'm sure I'm not the only one who has enlarged the internal diameter of carburetor system passages,petcocks and banjos on hopped up Guzzis. Just saying.....

[Rough Edge racing]

I'm sure I'm not the only one who has enlarged the internal diameter of carburetor system passages,petcocks and banjos on hopped up Guzzis. Just saying.....

  Yes, on the 1-1/2 mile LSR track some riders/driver will complain their  bike/car loses power near the finish...They put  in larger jets and still the same problem....Also a good way to fry a piston