Mine Must Be The Worst

[Noelfales]

Odometer read 79 miles when I had to go to reserve. Went a mile to the station, and she took 3.7 gallons. I am consistently getting around 20 mpg. Bike sounds fine and is ridden gently. What could cause  fuel consumption like this???

[Bone]

I ran out of gas in New Mexico getting similar mileage. I was running 80 + mph into high desert winds.

What were the conditions you rode in those 79 miles ? What air pressure do you think you have in the tires ?

Check them again to be sure what you really have they can lose air.

[Bighead]

Just went 140 on mine yesterday at 80 and it took 3.9 Gallons ( that is two up and loaded and much better than normal)

[DDT (12)]

Has anyone ridden behind you lately? I ask that because two of my buds who also happen to be great wrenches rode behind me and remarked about the smell of fuel... My Valk was running 'really rich' they said. It turned out to be the vaccum slides in the carbs; all six of them, were perforated and therefore leaking fuel.

It's really easy to check those, as you simply remove the caps on top of the carbs, pull the slides out and look them over. If you see any holes, then that's your problem... They are on the expensive side... at least mine were... about $50 bucks per, but that was in Canada... I don't know what they cost down here. Anyway, I'd start there... let us know what you find.

DDT

[Patrick]

Odometer read 79 miles when I had to go to reserve. Went a mile to the station, and she took 3.7 gallons. I am consistently getting around 20 mpg. Bike sounds fine and is ridden gently. What could cause  fuel consumption like this???

Anything been changed/modified ?

[Attic Rat]

where do you live? Are you close to me?

[Noelfales]

I live in Maryland, and there have been no mods to it by it's previous owner (a lady)

[Noelfales]

Also my tires are at 41 psi front and back

[Attic Rat]

I was hoping that you were closer. I know that I can fix it but that is a long way to travel.

[Noelfales]

Yep - too far to come - can you give me any ideas as to what the problem might be?

[John Schmidt]

Could be as simple as an extremely dirty intake filter, or some cracked vacuum hoses. Start doing a little bird dogging, check for loose clamps on the rubber sleeves leading to the carbs for starters. Could be a collection of things, could be the pilot jets are way off....hard to tell from a keyboard just what the trouble is. Keep us posted, there are other riders in that neck of the woods so help is available. Add your location to the profile so people can tell where you are.

[hubcapsc]

Cheapest and easiest... check your vacuum hoses... There's not much
room for hands in there. All the Chrome intake runners will come out easy,
making for much more room. And the chrome intake runners all have O-rings,
they could be replaced as part of your hunt.

could be your petcock. It's easy to rebuild.

    new petcock: 16950-MZ0-033

          - or -

    cover set (rebuild kit): 16953-MBZ-B51

    screen (why not?): 16952-MZ0-003

Could be the carb pistons mentioned in another post.
They cost some, might try that after the petcock rebuild.

     vacuum piston: 16111-MZ0-A00

[Pappy!]

Or at some point too many shims may have been placed under the needles. Possibly during a carb service the PO may have had done.

[slabghost]

I'd start by looking for leaks. As mentioned the hoses may be cracked or leaking. At idle spay a little start spray at carb fittings and vacuum lines and connectors. Don't forget the intake elbows at both ends. where the carbs attach and at the heads. Probably a relatively easy fix.

[Noelfales]

Some great tips - thanks to all - will follow up and keep you posted

[salty1]

If you pull the intake runners to inspect your vacuum lines as suggested by hubcapsc, check the setting on your pilots they should be turned about 2 turns out across the board. With the intakes out of the way it's would be quite simple.

[Firefighter]

I would look at the exhaust and spark plugs, see if they are sooty. Make sure the enrichment valve is off. My 2000 IS will get 30 to 35 mpg usually if I stay at or below 3000 rpms and twist gently. I get better mileage now than when I first bought the bike, cause I usually take it easy unless some Harley sneaks up behind me, then I usually decide to keep him back there!