Griso fuel pump outlet repairs

[belfastguzzi]

Tonight I got the crash damaged bike back together and running (apart from headlight but that's nearly sorted) on target for Sunday trackday.

 

Then another problem became apparent. On running, I could see a small petrol leak from the tank outlet. This is an old problem going back to the time of the cam recall and the terrible work done by the service agent. He damaged various parts of the bike, including the fuel lines and the quick release from the tank. This resulted in a broken plastic elbow. The elbow outlet is part of the pump and can't be bought / replaced on its own – and the pump unit is well over £300 to replace. That was too much to pay just because a tuppenny plastic part was broken – and it wasn't my fault. I got an engineering shop to ream out the surviving part of the plastic outlet nozzle and to make a steel tube outlet. I had hoped they would thread it in, but they glued it, saying the glue would last forever. I was sceptical but gave way to their experience.

 

However the glue has not held. It's probably been leaking for a long time.

I reckon that I should do what I hoped to do first time round. That is: find a metal screw-in elbow and get threads cut in the fuel pump base so that the new elbow can be attached. The red plastic part won't come out unless it's broken out, so I don't want to remove it until I can get a new elbow.

 

So I've got a few questions to find solutions to, pronto.

Where can I get a suitable outlet elbow? Where can I get someone to fit it / cut threads in the baseplate?

 

I'm really disappointed that this has happened so close to the Sunday trackday that I've had booked for ages. Maybe I'll superglue the tube in to the plastic part again, just to see me through the trackday.

Friday isn't the best day to get an urgent job done, even if I can find a suitable elbow.

 

 

 

 

Fuel outlet elbow with replacement hose that I fitted, instead of damaged plastic line and quick release.

 

 

Steel tube glued in where the plastic nozzle broke off.

 

 

 

Top part of outlet in baseplate casting.

 

[The Monkey]

Funny how when you defer to others experience against your own intuition, that which proves correct more often than not, allies to your own sensibility. Consider a Banjo fitting instead of an angled/threaded piece and finally eliminate that wretched piece of plastic from your fuel system. Banjo's have been utilized on Italian carbs and oil lines for ages and won't @#!#$# up like a cheap acrylic part. Have fun on track day.

[HaydnR]

Dave I'm not sure but this looks like the part that you need:

 

18. Coupling for Fuel pump

 

http://www.speedaway.co.uk/part/6463/2611-6463-ap8104192-coupling/per_page/12

 

part no. AP8104192

 

[luhbo]

... Maybe I'll superglue the tube in to the plastic part again, just to see me through the trackday...

 

No Superglue here, it's much too brittle and also not very fuel resistant. Get yourself a 2-component epoxy glue (over here I prefer Uhu Plus 300), preferably a slow curing one, and it will bring you through more than just one raceday. Heat makes them cure pretty fast and also improves their strength.

 

HaydnR's find looks like a real hack, btw.

 

hubert

[gstallons]

How is the red fitting held into the pump housing?

[HaydnR]

I have sent BFG a fitting from a spare pump that I had.

 

 

The fitting is held in by the tanged split washer which bites into the sides of the orifice. I've emailed the manufacturers of the fitting and of he pump to see if spares are available.

 

I found another picture of he aprilia pegasso pump,he fittings do look similar.

 

[gstallons]

Ok...I didn't know the bore diameter of the housing was to where it could be tapped to 1/8'' NPT and a brass fitting installed.

[HaydnR]

putting in a threaded brass fitting would be a nice solution.

[gstallons]

If the hole size will accept an 8mm or 11/32" drill bit, go for it ! You will be happier with that.

David, take it to a machine shop and ask for their advice first, then their help. You can get a 1/8" npt and 5/16" hose fitting (if that is the correct hose) and use it instead of the flimsy plastic fitting.

 

 

[belfastguzzi]

Excellent developments!

 

Thanks so much, Hayden.

 

 

 

 

 

 

Another question (sorry)

Can rubber fuel pipe be constantly immersed in petrol or should it only be plastic?

 

I'm wondering if I can replace the small piece of plastic pipe that runs internally from the pump to the outlet, with a short bit of rubber hi-pressure fuel hose? The plastic stuff seems to be 'use once' It retains the shape that it gets fitted to and so doesn't come off very well. This piece has been off a couple of times and isn't in best shape.

 

I'm thinking that the rubber pipe if totally and constantly immersed would get soft?

[gstallons]

That is about the way it is with the plastic hose. If you can get the hose back on and clamp it, I would do that. You want to use hi-pressure fuel injection hose on the exterior along with fuel injection hose clamps. They have a piece inside of the clamp that keeps from cutting the hose. They are easily identified. There are European and U.S. variations too. Google the part and see what you come up with.

You could eBay the parts and see what is out there.........

[belfastguzzi]

Update on the plastic fuel elbow as used by Guzzi, Aprilia, maybe Ducati? Triumph?

And has been broken on various Grisos (possibly other models too?).

I think it gets broken because the quick disconnect is awkward to get at and difficult to use and itself gets broken. The fuel line on the Griso is short, so it is too easy to raise the tank (without the fuel line disconnected) and suddenly there is a snap as the plastic nozzle comes under tension and snaps off.

 

I've seen some pics of an early fix (USA) where some sort of pipe was brazed in.

There has been discussion of threading in a metal elbow...

and as I couldn't find an elbow at the time, my solution a year and a half ago was a glued-in steel tube.

It worked, until the glue eventually gave way to the petrol.

 

 

 

Now I think that rather than an aftermarket elbow, a banjo union will be best, as it can be positioned to point in the best direction.

I got one without knowing what size the baseplate hole would be: it's actually too small, but looks to be the right idea.

 

 

On the Friday before I wanted to do a Sunday track day (after other crash repairs to the Griso) I glued the steel tube back into the plastic part to see me through the track day and I'm confident that it would have lasted another year. However Hayden in England contacted me to say that he has a V11 pump and he posted me the plastic elbow from it. It arrived next day, on Saturday morning.

 

 

 

I fitted it and all was sorted for the Sunday. Great!

 

Ultimately a metal outlet will be better as the plastic is fragile. However the main need to still explore alternative solutions is that the manufacturers of the plastic part won't supply it to you or I. If anyone else goes down the route of a threaded elbow type of repair, please post details.

 

When the plastic piece was out, I could see that there is plenty of metal in the baseplate to tap threads into.

 

 

 

 

 

 

 

I'll do the job some day.

There is no rush as the bike is going alright.

Thanks Hayden! Another fabulous example of forum help coming to the rescue (when the dealer and importer system does nothing for us).

 

 

 

 

[gstallons]

It looks like a one time application with the o-rings having to into the bore and then the barbed retainer holding the fitting in. When you push the new fitting in it passes the portion that is scratched from the retainer of the original fitting.

[belfastguzzi]

well, yes: like many parts it's intended to be a one-time fitting, but as we know, it's not actually good enough, robust enough, to last for the life time of the bike. So as with most other issues, we have to find a way to work around the manufacturer's intention, which is that you throw away the complete pump and buy a complete new one just because one part has failed – at a cost that is 1,000 times greater than the cost of the failed part.

 

The first postings on finding a fix said that the plastic piece (intended as a one-time fitting) needs to be broken out – which is what I was expecting to do. However it can be gotten out in one piece, as Hayden advised me. I used a combination of pushing and levering to get past the difficult point, which is to get the direction of the tangs reversed. There is a lot of resistance until that is done. It's a bit problematic because a drift does dig into the plastic and could punch through it without care. Eventually I dropped a piece of lead into the elbow to cushion and spread the stress. I found it best to lever it from the outside as well, once there was enough of a gap to do that.

 

I don't think that you need to worry about the tang scratches in the alloy damaging the o-rings. But... I'll see how it goes. Definitely, threading in a metal elbow will give the best long-term confidence.

 

I do think that it would be good to be able to buy the plastic part – even to carry as an emergency spare.

If your outlet snaps while away on a trip (not inconceivable) what are you going to do? You could easily and quickly carry out a roadside repair if you had the cheap replacement part (you don't even need to completely drain the fuel) but you might find it a bit troublesome to locate a new fuel pump or to pay for it and it would be a right palaver having to locate someone able to fit a threaded elbow.

[gstallons]

David , I see and understand your logic.. You need to work on cars, well any kind of transportation vehicle to see that module replacement is the way it's done now.

BTW, what is the diameter of the fitting that pushes into the bore of the pump module?