A few things fuel related.

[activpop]

After having my 2001 Sport languishing on the stand for way too long, I finally have the whole rear end put back together with new uni joints. There were some little roadblocks along the way with the new crosses because they were not exactly the same as the old ones, but I worked it out and it should be history now. I will explain in more detail in another post. 

So I was anxious to give it a road test and while it was still on the stand I figured I would fire it up. It hasn't been running in a couple years but I had last drained all the fuel and replaced it with non-e and it has been run through the system. It started up pretty quickly and as it was idling I noticed a gas was dripping out onto the stand, a pretty good amount. Shut it down immediately and cleaned it up. This was not good. Turned the key on to start the pump and saw drips again, so that was enough of that. I couldn't see where it was leaking from but it seemed higher up under the tank. 

Today I removed the tank and looked closely at everything. I removed the tube from the left side fuel solenoid valve (some diagrams call this a fuel cock?) that connects to the inlet side of the fuel pump. I think it could have been leaking there because of the hose condition but not sure since this would be the suction side. The hose ends were not the most pliable and seemed dried out a bit. The male barb coming out of the rear of the pump had some corrosion and pitting which didn't look great. You can see that in the close up. So I am still not sure of the cause. I will replace tubing.

A few questions...

- The hose that runs around the top of the spine is squished.  That doesn't look too good. Right? Is that from tank deformation?

- The small rubber hose to the left of the pump that is not landed looks like the remnants of an evap system that was removed. That hose daylight under the engine. That can go bye bye, right?

- When I was trying to remove the hose from the fuel solenoid valve, I noticed it starting to move. After taking off the tank,  I unscrewed it all the way and noticed there was no gasket. Is that just relying on compression to seal?

- The tank underside has two hose barbs coming out. One has a tube connected to the old check valve that I assume was part of the evap system. The other bard is open and not connected to anything. I don't have a clue if that is correct. Doesn't seem that way. 

-  Lastly, the fuel filter seems to be a bmw unit, so I assume it was changed at some point.  The tubing is Gates. Worm drive hose clamps are used throughout. There were not on the bike from the factory, right?

[docc]

Another great topic. This is going to take some sorting . . .

[docc]

Moving the pump to the top of the frame was, IMCO, a factory effort to address "vapor lock" reports.

At this juncture, I believe the pump is better mounted to the left side of the frame, groomed forward with the petcock-to-pump fuel line shielded and as short as possible to keep it away from the head fins.

With the fuel filter mounted top-side on the SpineFrame, the fuel line from the pump to the filter can be lengthened to mitigate that pinch.

 

[activpop]

At this point I'm going to replace gas lines. No reason to ignore that with everything off.

Here is a pic of another tube not landed that was under the air box. I assume this was evap stuff? I thought it could be airbox drain, but see landing point for it. The 8v airbox has drains that drop down close to ground, but they are plugged to prevent oil on the tire. This one daylights to the same spot, but no plug. It's not connected up top though.

[activpop]

...see no landing point for it.

[docc]

7 minutes ago, activpop said:

At this point I'm going to replace gas lines. No reason to ignore that with everything off.

Here is a pic of another tube not landed that was under the air box. I assume this was evap stuff? I thought it could be airbox drain, but see landing point for it. The 8v airbox has drains that drop down close to ground, but they are plugged to prevent oil on the tire. This one daylights to the same spot, but no plug. It's not connected up top though.

Pretty sure that is your fuel filler overflow line that connects to the right side under-tank nipple and dribbles fuel overflow/ under-cap wetness out below the gearbox.

The valved tubing from the left side is the fuel tank venting. Those valves were a known fail point and many removed them, routing the vent below the gearbox or joining it with the overflow tube.

[Lucky Phil]

You could re arrange everything like my bike I guess. EFI Fuel hose often leaks after long term storage at the clamps and after a bit of running they swell and seal again.

Phil

Edited March 3 by Lucky Phil

[docc]

That pinch damage ain't gonna swell closed. Even without changing component placement, that hose just needs to be longer.

[activpop]

28 minutes ago, docc said:

That pinch damage ain't gonna swell closed. Even without changing component placement, that hose just needs to be longer.

Yep, I think you're right on that. Looks like the BMW fuel filter is shorter than the stock one, so they just pulled the hose to the nipple to fit it on. It will be new and longer. New filter going in too.

[activpop]

38 minutes ago, Lucky Phil said:

You could re arrange everything like my bike I guess. EFI Fuel hose often leaks after long term storage at the clamps and after a bit of running they swell and seal again.

Phil

Looks pretty neat there Phil, but I think I'll just rejuvenate what I have. Thanks for that pic!

Also, never thought about the hoses drying out when they sit like you mentioned. All the more  reason to replace them. New hoses won't do that. They were a little brittle at the ends.

Edited March 3 by activpop

[activpop]

So @docc, the tube that is on the tank with the check valve on it looks like it goes to the tank vent. Those are on the right side. The left one that had nothing on it looks like it goes to the overflow inside the filler neck. There is no way that hose in the last pic goes to that nipple, way too short. But the smaller hose  that is laying to the left of the fuel pump is the one that should be connected to the overflow nipple. It has the length, but no clamp, so maybe it fell off some time ago. It wasn't connected when I lifted the tank a bit to look what all was under there before attempting lift-off. 

Funny thing is, that hose that was in my last pic still had the SS pinch clamp on it. Once they are clamped, they never come off. I'm still at a loss to where that one went.

[docc]

I wonder if the pump on top of the frame arrangement allows the filter to be changed without a tank off?

[docc]

2 minutes ago, activpop said:

So @docc, the tube that is on the tank with the check valve on it looks like it goes to the tank vent. Those are on the right side. The left one that had nothing on it looks like it goes to the overflow inside the filler neck. There is no way that hose in the last pic goes to that nipple, way too short. But the smaller hose  that is laying to the left of the fuel pump is the one that should be connected to the overflow nipple. It has the length, but no clamp, so maybe it fell off some time ago. It wasn't connected when I lifted the tank a bit to look what all was under there before attempting lift-off. 

Funny thing is, that hose that was in my last pic still had the SS pinch clamp on it. Once they are clamped, they never come off. I'm still at a loss to where that one went.

I could have my "right and left" mixed up looking upward at your under-tank image. One is the tank vent and one is the overflow. Both could be combined to atmosphere with a single exit below the gearbox.

 

[Lucky Phil]

On the subject of hose clamps these are the best. Re useable and the special tool isn't required. Neat, compact, simple and reliable. I hate screw clamps on small hoses. They look like shite.

5/16 EFI hose needs the "purple banded" Norma Cobra clamps. You can buy them at many places or on line.

https://www.irrigationworks.com.au/hose-clamps

 

 

Edited Monday at 03:58 AM by Lucky Phil

[gstallons]

The clamp set-up Phil has looks pretty good . i use a conventional high pressure fuel injection hose clamp that covers the entire circumference of the hose and doesn't let the worm gear "threads" dig into the hose . Also buy a good (long) length of fuel injection hose. It will give pressure rating on the length of hose. Gates is the best , NAPA , then you need to be careful. Anyone else on brand recommendation ? This fuel line on the bike is approximately 20-25 yrs old . Remember this having the tank off. Also , when you have anything off under the tank , make sure nothing is going to touch , rub or damage ANYTHING else when you are going back together.

 Also , I use a small amount of Sil-Glide when assembling hoses to make them easy to go together and come apart. The two vents under the tank use a tee to make one hose to vent down & out of the way .