Has anyone got any advice on how to replace the main and reserve petrol feed pipes on a '76 CB550 F1.?

Question

They pass through holes in a bracket in front of the carbs that seems impossible to remove without taking the carbs out, which seems a bit excessive just to replace the pipe.

I can remove the pipes from the carb end but have no idea how I am going to refit them?

The Haynes manual is totally useless on this subject!

Any help would be gratefully received.

Cheers

Dave

Answer 1

That wasn't one of Honda's better Ideas.

Maybe their Worst.

It wasn't Bad Enough,,,so they added 2 instead of just One,,,so You'd have to Fight it Twice.

I had forgotten all about that Nitemare,,

I still cant beleive they shrouded the Fuel Inlet so TIGHTLY between the the Throttle mechanism..

If they simple made Longer fuel Inlet Nipple so it wouda extended Through the Carb Mount Plate...

It woulda been normal as any other bike.

?????

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This is no matter, either way,,,but just for the sake of Knowing....

Both hoses are Main Fuel Delivery.

One each per Pair of Carbs.

A Left Pair and Right Pair.

Reserve function is all in the Tank Petcock itself.

Inside the Tank,,,the Petcock has Dual Fuel INLETS.

One at a Higher Level in the tank for "Main".

And one at a lower level for Reserve.

They both eventually deliver fuel to a common plenum in the Petcock's body,

The the Petcock's  Valving selects which INLET is Open accordingly,,,while it blocks the Other.

When in OFF position,,BOTH Inlets are blocked.

Downstream of the valve,,,,the OUTLET from the VALVE is  simply "T'd" into 2 Petcock Outlets.

One for each pair of carbs.

Makes no difference which Fuel hose goes where

.........................................

To be honest---You can fool with them a Long and frustrating time,,,and will eventually come to the conclusion

"I would have been better off to just Remove the d**n things,,,and I'd be done by now"

They are LOTS easier and faster to Remove & replace.

............................

However,,,there ARE a few Cheats to get Fuel to  

the carbs.

To do it same as Original:

SOMETIMES this works.

Get a Metal Rod which will fit thru thru hose Loosely.

Bend it into a Sweeping Radius "L",, but Not with a 90* Angle.

Difficult to Describe the Shape needed.

First,understand what the Rod is going to Do.

--A) The Hose is Floppy,,,You can introduce it to the Carb Fitting,,but near Impossible to push it on.

The ROD thru the Hose puts "some Lead in the Pencil" so to speak.

It creates a Rigid Guide,,which controls the Hose.

You can then Push the Hose from the far end,,,and it's constrained to Only Slide down the Rod.

It cannot crumple and go off in any direction.

---B) The Rod also lets you "Steer" the Hose and helps Hold it in position as You Push.

When Done,,,simply slide the Rod Out.

Ok,,With that principle in mind,,

Next thing is SHAPE of the Rod.

The Carb Inlet Fitting is in a Place that does not allow a "Straight-Line " Push.

All the Proximity to Other Parts  does not allow much Working Room.

You must Approach that damned Hole in the Carb Mount at about a 30* Angle,,

Then You must Push  Straight Back,Horizontally.

Easiest Way to Describe it  is to imagine a CLOCK FACE.

And I'll describe it based on the Actual Use,,,the Approx Position  you'll be holding/using the tool.

Ok,,,

LONG Hand on the Clock is at approx 10:00 to 11:00.

Short Hand is at about 3:00.

So You end up with

Down at an Angle to a "center point",,,

then straight across to the carb.

You want a Sweeping Angle,,,a Radius at the "center",,,,not a sharp kink.

Simply so the Hose will slide easily.

In the States we have Wire Clothes Hangers that we use to Rule the Technical World and Dominate the Laws of Physics.

More Important to Us yanks than invention of Fire or Wheels.

Seriously,,,You'll Need a STIFF Rod or Heavy gauge Steel Wire,,,,about 1/8"~3 MM or so.

When You get your guide made,,,and have your Hose on it,,

Jockey it around into position and use some Pliers to pinch the hose and push it onto Carb.

Helps to Lube the Hose ,,You can use any Spray Lube or even motor oil.

Hose Clamps???

That's another Fight,,,and theres No Easy Way I know of.

If You have the original thin wire Honda Clamps,,

You can put those onto the hose intitially,,,and They will still allow the hose to be Pushed On whil the clamps are in place.

With NEW Hose,,,which is a MUST DO anyway,,,lots of people dont even Use Clamps at all.

I Dont recommend that,,it's Not Right,,NOT Good.

But I've seen 1,000's of Bike Fuel Lines that way with No Clamps,,,and no problems.

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Another Cheat is to just RE-ROUTE the Hoses.

Those Fuel Inlet fittings on the Carbs  SWIVEL.

At this age,,,they may be Stuck.

And they are Always stiff.

Originally they are pointed Forward to match the Hole in the Carb Mount Plate.

If Possible,,,You can Swing them DOWNward so they are at an angle aimed Underneath that Plate,,,or Straight Down...or even Backwards.

It's Fairly Easy to get the Hose pushed on from UNDERNEATH the Carbs.

To Do all That,,You'll need LONGER Rubber Hoses,,,

and will have to "LOOP" them back around Underneath the Carb Mount Plate ,then Up.

It's VERY IMPORTANT to mind the ROUTING of the Hoses and Tie them Securely in Place.

There is More MOTION happening with the Throttle Assembly than the whole rest of the Motorcycle...almost:).

Point is,,,BEWARE of Interference with the Throttle Linkage,,,and be CERTAIN the Hoses are well anchored in a secure position.

Cable Ties work a treat.

Down & Around the Back & then UP & OVER the carbs is often Easiest to achieve.

But that Hose routing is the MOST Demanding in terms of Avoiding Throttle Linkage.

It's EASY,,,,but there's More stuff happening along That Route with Throttle,

So be Extra Certain the Hoses are Well Clear and Well Anchored.

It's VERY WISE to include an Inline Fuel Filter spliced into each Fuel Line.

Certainly for the Filtration,,,but also because it creates a  Connection Joint that is Lots easier to work with.

Your Choice mate.

1)Remove them,,,which really ain't that difficult,,,not as bad as it looks.

or,

2) Use a guide Rod inside the Rubber Hose to steer & push,,,,remove it when done

or,

3) Swing the Carb Fittings round to an appropriate angle.

You can Them run the hoses:

a) Under the carb Mount & toward the Front

or

b) Toward the Rear,,,Down and around  & Loop them over the Top of the Carbs.

* I've seen some with Very Long Hoses,,,

Routed Down then ACROSS,,,and up to the Petcock.

ANY way You want to Route them is Fine & Functional.

But I cannot Overstress the importance of Avoiding Interference with Throttle Mechanism.

Good Luck

Answer 2

Remove the fuel tank.

Use long thin needle nose pliars.

Before installing the new hose, spray the inside with "contact/brake cleaner" (available at auto parts and bike shops) - it will make the hose very slippery and the cleaner will not affect the carbs or fuel.