Loss of power

[TrapperAH1G]

I've read about this on here but can't find it again.

Loss of power on freeway.  Can feel when it loses power, like heading into a strong wind.  Gets worse and will die if I keep on riding.  Found that if I turn to reserve it gets better.  Recently had the tank off to service filter and synched the carbs a few days later. 

Visually looked and don't see any kink in hose(s).  No whoosh of air when I open the gas cap.

Guess I'll pull tank and replace petcock.  Have new OEM.  Also, can the fuel line from the petcock be changed without pulling the cleaner housing?  Have a fuel filter on the line and would like to remove it.

Finally, will the bowl drain hoses cause problems if there's a crack in the line?

Thanks

[da prez]

Fuel filters usually cause problems.  Fuel system is touchy. Check all vacuum lines. Are you de desmogged.
 Go thru it step by step. Let us know.

                  da prez

[sandy]

Before replacing the whole petcock, put a rebuild kit (cover set) in it. Also, at speed the vacuum drops down. If the cover set has a pinhole or the vacuum tube is old and has a split, the petcock will begin to shut.

[Jess from VA]

In the meantime, you can close the gas cap on a thin zip tie to vent. 

Not on a full to top tank, and be careful on the sidestand. 

And BTW, some of us fill up sitting on the seat (level), and right up to the neck (only if you have a slow feed pump).  But don't do this, then immediately (or a mile down the road) put the bike on the stand, in the sun.  The tank will burp gas.   

[Avanti]

Remove fuel tank, air box cover, air filter, and air box to remove fuel filter.
Measuring back from the carburetor crossmember, cut the hose at 5.25". The 5.25” will be a complete full on fit to the OEM fuel shutoff.  I usually will cut at 5.125”. Use fuel injection clamps to install. The 9.5mm ID hose can be picked up at a Oreillys Auto Part store, part number  (Prestone #FJ0308)

[TrapperAH1G]

Desmogged.  Going to replace the vacuum hose with the petcock.  Was hoping I could do the fuel line without removing the air box, heard it's a PITA to put back on.  As I said, don't see any kink, etc., in the vent line...should I blow a little air through the vent pipe just to check/clear?

Thanks

BTW, I usually fill my tank while on the bike.  Thanks for the tip(s) about filling, the sun, etc.

[The emperor has no clothes]

Desmogged.  Going to replace the vacuum hose with the petcock.  Was hoping I could do the fuel line without removing the air box, heard it's a PITA to put back on.  As I said, don't see any kink, etc., in the vent line...should I blow a little air through the vent pipe just to check/clear?

Thanks

BTW, I usually fill my tank while on the bike.  Thanks for the tip(s) about filling, the sun, etc.

It’s likely the filter blocking full flow. You will need to remove the air box. It’s not as bad as some make it out to reinstall. Use a ratchet strap to snug it into place as you get all the air horns on to the carbs.

[RonW]

I use a 90° pick to make sure the rubber snorkels are properly seated on the intake runners carbs (bottom pic) and facilitate the overall installation. That step is the main snag. It's from an inexpensive pick set that I already had not a professional hose pick but does the job. A telescoping inspection mirror is handy too. Some even have a led light.

[Valkorado]

Just curious if you're using an electric fuel shutoff (Dan-Marc)?

[Jruby38]

Your problem is the POS OEM fuel shutoff not being able to deliver fuel fast enough at highway speed. I had the same problem years ago. Replace it with a Pingle .  You can't outrun it even WFO.

[Mooskee]

Remove fuel tank, air box cover, air filter, and air box to remove fuel filter.
Measuring back from the carburetor crossmember, cut the hose at 5.25". The 5.25” will be a complete full on fit to the OEM fuel shutoff.  I usually will cut at 5.125”. Use fuel injection clamps to install. The 9.5mm ID hose can be picked up at a Oreillys Auto Part store, part number  (Prestone #FJ0308)

Correct, which equates to the length of the line from the OEM petcock to the TEE being 8 inches.

If you have a Pingel petcock installed the length of the line is 8 3/8, because the Pingel nipple sits 3/8 inch further back.

If you have a "Dan-Marc" in the line you of course have to adjust accordingly for the space the Dan-Marc takes up.

As has been discussed much, making the line longer is likely to cause it to sag and form a loop seal, which will restrict fuel flow.

[TrapperAH1G]

All done.  Replaced the fuel line and vac hose from #6.  Replaced the petcock.  When I took out the old petcock, the filter "sleeve" was separated and hanging out of the tank about an inch and a half.  Tried pulling and it wouldn't come out.  Finally, got the wife to hold the tank and grabbed the "tail" with pliers and pulled.  Had to keep pulling and moving it around to get it to line up and come out.  Phew!

Other than that, it was just a time consuming PITA getting the air box out and back in.  Came very close to being able to replace the fuel line without pulling the box, but not quite.  Got the new line started on the tee, but couldn't quite get enough leverage to seat it.  Hopefully, won't have to worry about this line again.

Buttoned all up and went for a test ride.  About 80 miles and all is well.  The old gurl is back!

Thanks to all for the comments, suggestions, tips, etc.

Ride safe, be well.

[Craig9409]

Nice. I'm glad you got it all figured out. That's why these forums are so valuable.