MPG and miles to reserve don't add up

[Chiefy]

Hey,
  This is making me bonkers.      I have a standard which is supposed to be 4.2 gallons to reserve.  When I'm driving "safe and sane" I get around 34 mpg, and I hit reserve at about 117 miles, it takes about 3.4 gallons to refill.  When I'm twisting the throttle a lot, I go about 88 miles to reserve (25 mpg.)

I've never run the tank all the way out.  But at 34 mpg, I should be able to go about 140 or so miles to reserve.  What's most likely going on?  Something clogged inside the tank??

Oh, FYI.... When I fill up, I fill to about 1/2 to 1 inch above the bottom of the collar that the gas pump goes in.  On my VTX, if I fill higher then that, it will puke gas all over the "boys" once I get rolling.  So I didn't want to find out the hard way if the Dragon does that too.

[Garfield]

I get about the same as you, 32 to 34 miles per gallon on my standard unless my wrist gets out of control I fill mine up all the way to the top. I put as much as I can in the tank and haven't had a drop come out, so I think you will be safe in filling her up all the way to the top.

[Chiefy]

I get about the same as you, 32 to 34 miles per gallon on my standard unless my wrist gets out of control I fill mine up all the way to the top. I put as much as I can in the tank and haven't had a drop come out, so I think you will be safe in filling her up all the way to the top.

How many miles to reserve at 34 mpg for you when filling to the top?

Gas and the boys are not a fun mix   

[Garfield]

How many miles to reserve at 34 mpg for you when filling to the top?

Gas and the boys are not a fun mix   

LOL, I should find out exactly what mine is. I've only had her sence the end of june. The PO told me that it will go 180 miles before I needed to fill it up. I think he was talking about his car So I filled her up that day and ran out of gas at between 130 and 140 miles. Thank god I ran out in front of a gas station. I normally start to look for gas now at around 100 miles.

[98valk]

per '98 std owner's manual
"std tank 5.28 gal 1.14 gal reserve"  4.14 gallons to reserve.
"fill to filler neck, there should be no fuel in the filler neck"

per motorcycle consumer news , odo is off, runs negative error of 2.857%, for every 100 miles add 2.857 miles.

[Chiefy]

per '98 std owner's manual
"std tank 5.28 gal 1.14 gal reserve"  4.14 gallons to reserve.
"fill to filler neck, there should be no fuel in the filler neck"

per motorcycle consumer news , odo is off, runs negative error of 2.857%, for every 100 miles add 2.857 miles.

Well then the math is *really* off.  I'm filling higher then that, and going 3.4 gal to reserve.  I assume part of the pick up in the tank has to be clogged.

[tank_post142]

most likely your getting less than 34 mpg and that's all there is. drained dry and sitting for 2-3 weeks empty i can get 4.9 gals in my standard tank. that's right to the bottom of the filler neck with no air in the tank.

[bigvalkriefan]

I filled up the other day and put in 4.101 gal and I had not put it on reserve yet. I fill up to the bottom of the neck and then I can squeeze in another 1/2 gal, going real slow and stopping, giving it time to settle and going again. I have not had any spillage on the boys.

[Tropic traveler]

My '97 is very consistent. 120-130 miles & I hit reserve, sure enough it takes right at 4.125 gallons to fill. A few less miles if I'm hauling azz. I do fill it very high when I know I'm riding right away, no seepage issues. I fill Kim's '98 the same way & she gets over 150 miles before going to reserve. Must be the difference between the thirsty '97s & the other years, less powerful Valks  .
Both Valks have had the petcock & screen replaced so I know everything is clean & right there. I had a rust problem with my '97 a few years back & after fixing that I added an inline fuel filter. Occasionally it would do the run out of gas routine at 90-100 miles then take only 3.5 or so gallons to fill up. I found that switching to reserve for a mile or so then switching back returned things to normal.
I would pull the tank & check the filter screen or replace it. Take a hard look at the petcock if you have not rebuilt or replaced it recently. It's age more than miles when it comes to the Valkyrie's fuel system that counts.

[Chiefy]

most likely your getting less than 34 mpg and that's all there is. drained dry and sitting for 2-3 weeks empty i can get 4.9 gals in my standard tank. that's right to the bottom of the filler neck with no air in the tank.

I guess that's one explanation that I hadn't considered.  But I think I would notice if the ODO/MPG were off that much over something like 100 miles.  Maybe I'll strap my GPS on it to rule it out.

[Chiefy]

My '97 is very consistent. 120-130 miles & I hit reserve, sure enough it takes right at 4.125 gallons to fill. A few less miles if I'm hauling azz. I do fill it very high when I know I'm riding right away, no seepage issues. I fill Kim's '98 the same way & she gets over 150 miles before going to reserve. Must be the difference between the thirsty '97s & the other years, less powerful Valks  .
Both Valks have had the petcock & screen replaced so I know everything is clean & right there. I had a rust problem with my '97 a few years back & after fixing that I added an inline fuel filter. Occasionally it would do the run out of gas routine at 90-100 miles then take only 3.5 or so gallons to fill up. I found that switching to reserve for a mile or so then switching back returned things to normal.
I would pull the tank & check the filter screen or replace it. Take a hard look at the petcock if you have not rebuilt or replaced it recently. It's age more than miles when it comes to the Valkyrie's fuel system that counts.

When I bought it, (Sept '10) the dealer cleaned the carbs under warranty.  When I picked it up, the mechanic who did the work was outside.  He told me he checked the inside of the tank and there was no rust.  Since HE brought  it up, I assumed he was on the level.  He also added a small inline filter.  

I have not removed the petcock, so I haven't seen how it picks up gas inside the tank.  I'm picturing some type of vertical arrangement.  I suppose if the lower part were clogged, it would cause something like I'm describing.

Before I pull it apart and check, anyone have some tips?

[olddog1946]

I have an 01 std, next door is a 97 std,,,we ride together, usually get from 110-130 before hitting reserve...at any rate, you go 120 miles, put in 4 gals you get 30 mpg, or 3 gals = 40 mpg..I have never been able to put more than 4 gals in the tank at one time, so I don't think the advertised levels are to accurate (capacity and reserve level) and don't really care..mileage driven, divided by gals added = miles per gallon...

SO, IF I AIN'T WALKING, ALL IS GOOD..

[Pete]

My 97 when run to reserve on moderate to warm riding is 150 to 155 miles and 4 gallons(38MPG) consistently. When the weather is cold and use of the choke is longer and warm up is longer MPG really suffers (34MPG).

But still hits reserve at about 4 gallons of usage.

Has the rear of you bike been made higher or the front lower? Changing the angle of the fuel tank. If so that could account for hitting reserve a little earlier.

As for the screen that is easy to check but unlikely, as a clogged screen usually shows up on reserve (lower part of the screen).

Run five or 10 miles on an interstate and use the mileage markers to see how you odometer checks out, not a scientific measurement but close enough to answer the question.
 
An inline filter that is not free flowing can reduce flow just before reserve is hit and late into reserve due to reduced fuel pressure. If you have one.

[Tropic traveler]

Since you have an inline filter added I suspect it may be the cause of the "premature reserve" syndrome you have. Try filling it up as full as you can, maybe the extra weight of more fuel will work out better. The filter I added has been in for 26,000 miles & it rarely gives me that problem anymore. Don't know why that is.
Was your filter installed in a loop or straight inline? I used a '70s era Ford filter installed straight inline, no loop.

[sandy]

Before diagnosing my bad petcock, it had similar symptons. Try this: When you have to hit reserve, wait a mile or two and go back to "ON" and see how long it lasts before needing reserve again. I had to rebuild the cover set to fix it. The diaphragm must have had a pinhole in it.

[Chiefy]

Since you have an inline filter added I suspect it may be the cause of the "premature reserve" syndrome you have. Try filling it up as full as you can, maybe the extra weight of more fuel will work out better. The filter I added has been in for 26,000 miles & it rarely gives me that problem anymore. Don't know why that is.
Was your filter installed in a loop or straight inline? I used a '70s era Ford filter installed straight inline, no loop.

It's installed in a straight line, and it's a tiny little thing.

[Chiefy]

Before diagnosing my bad petcock, it had similar symptons. Try this: When you have to hit reserve, wait a mile or two and go back to "ON" and see how long it lasts before needing reserve again. I had to rebuild the cover set to fix it. The diaphragm must have had a pinhole in it.

Someone else mentioned that too.  I'll try it and see what happens.

I seem to recall the day I picked it up (no fuel filter) it ran for several miles with the petcock off 

Now it doesn't run long once I hit reserve or turn off the petcock.  Maybe I'll bypass the fuel filter for a tank or two to see. 

[Gryphon Rider]

I suspect that either your newly added filter isn't flowing as it should, or you have a petcock vacuum diaphram leak, or you have a vacuum hose leak that effects the fuel valve vacuum shutoff.  When I fill up my Tourer after just having hit reserve, I put in 4.4 gallons filling above the bottom of the filler neck, with the bike on the side stand.  If there are fuel flow problems, the bike will act like it wants reserve.  Next time this happens, pull over and either shut it off or let it idle for a couple of minutes.  If this seems to cure the problem temporarily, then you know you haven't acutally hit reserve, but have a flow problem.

[valkmc]

I use to hit reserve around 110-120 then my petcock started to smell like gas. I rebuilt it with the kit from HDL and cleaned the screen. I now hit reserve at 130-140. It takes more gas to fill and my MPG have not changed much, I get between 32 and 38 depending on my mood which seems to effect my wrist action. I guess I was not getting all of the gas out of the tank prior to the rebuild.

[Chiefy]

Okay, thanks for all the input.  I'm going to see if I can find a filter that has good flow, and I guess I'll rebuild or replace the petcock.

[John U.]

Check the Golan filters. They are a bit pricy but the filter to a claimed 6 microns IIRC. Oh yea, the screen is cleanable.
Jegs has them. I've been using one on two bikes fo a few years and no fuel flow problems.

[Momz]

My 98 standard has gone 200+ miles several times before hitting reserve. I never ride conservetively, Valks aren't meant to be ridden slowly.

But I have made a few modifications: full desmog, polished intakes, simple ECT Mod, I/S ICM and carb springs.
Have you checked the condition of your air filter lately? I've found several riders that don't check/replace the air filters on a regular basis. Tire pressurse must be correct or your gas mileage and tire life are going to go down the drain.

I'm planning a Gas Mileage Challange ride during IZXI, and it will definitely be a sporting ride. Would you be up to a challenge?

[GOOSE]

mine consistantly gets between 39-42 mpg .......just basing it on gallons put in the tank.....but as we all know the red and black model do seem to get better gas mileage.

[Chiefy]

Tire pressure is fine, and air filter has about 750 miles on it.  It's not performance, or MPG, it's miles to reserve........

Was looking at the OEM kit, with screens, and said screw it, let's go bowling............

No, actually I said screw it, and ordered a new Petcock.  I'm the third or fourth owner of her, don't know what the previous guys did.

[bigvalkriefan]

My 98 standard has gone 200+ miles several times before hitting reserve. I never ride conservitively, Valks aren't meant to be ridden slowly.

But I have made a few modifications: full desmog, polished intakes, simple ECT Mod, I/S ICM and carb springs.
Have you checked the condition of your air filter lately? I've found several riders that don't check/replace the air filters on a regular basis. Tire pressurse must be correct or your gas mileage and tire life are going to go down the drain.

I'm planning a Gas Mileage Challange ride during IZXI, and it will definitely be a sporting ride. Would you be up to a challenge?

Holy moly Moms, 50 mpg, on the highway, not babying it?

[Momz]

bigvalkyriefan,

Not quite 50 MPG, but close to it.
I forgot to mention that I have raised the front of the tank. Without a windshield this allows for greater airflow to the airbox and may also effect the fuel pickup at the petcock. My bike is stripped of all nonessenceal parts like the backrest and the stock turnsignals and other parts like the rear master cylinder cover, and the stock handelbar riser cap with Magna parts.

However I've also gotten in excess of 44 MPG on my I/S. Don't granny the bike, but ride sanely swift and you may be amazed at the MPG.

Come to IZXI and join the Fuel Mileage Challenge, you won't be disappointed.

[98valk]

in regards to the extra fuel filters some are installing. first off I don't believe in it for a gravity feed system which already has a tank filter and screen filters in each carb bowl inlet.

so that being said, if fuel flow is reduced to the carbs, this will lower the level of fuel in the bowls during operation. A low fuel level in the bowls will effectively raise the air fuel ratio causing a lean condition and vice versa. this will require more throttle to be used then normal. this is based on what the engine wants. this amount of throttle opening greater than 1/8 throttle, will make the bike run on the needle circuit instead of the pilot circuit while cruising down the hwy, thereby greatly decreasing MPG.
Marc at factorypro stresses greatly the importance of float level when tunning any bike. the valkyrie carbs have fixed float adjustment levels, making tuning easier.

[Chiefy]

in regards to the extra fuel filters some are installing. first off I don't believe in it for a gravity feed system which already has a tank filter and screen filters in each carb bowl inlet.

so that being said, if fuel flow is reduced to the carbs, this will lower the level of fuel in the bowls during operation. A low fuel level in the bowls will effectively raise the air fuel ratio causing a lean condition and vice versa. this will require more throttle to be used then normal. this is based on what the engine wants. this amount of throttle opening greater than 1/8 throttle, will make the bike run on the needle circuit instead of the pilot circuit while cruising down the hwy, thereby greatly decreasing MPG.
Marc at factorypro stresses greatly the importance of float level when tunning any bike. the valkyrie carbs have fixed float adjustment levels, making tuning easier.

Interesting.

[Tropic traveler]

in regards to the extra fuel filters some are installing. first off I don't believe in it for a gravity feed system which already has a tank filter and screen filters in each carb bowl inlet.

so that being said, if fuel flow is reduced to the carbs, this will lower the level of fuel in the bowls during operation. A low fuel level in the bowls will effectively raise the air fuel ratio causing a lean condition and vice versa. this will require more throttle to be used then normal. this is based on what the engine wants. this amount of throttle opening greater than 1/8 throttle, will make the bike run on the needle circuit instead of the pilot circuit while cruising down the hwy, thereby greatly decreasing MPG.
Marc at factorypro stresses greatly the importance of float level when tunning any bike. the valkyrie carbs have fixed float adjustment levels, making tuning easier.

Interesting theory but..... that has not been my experience having actually installed the inline filter & actually run the bike for over 26,000 miles. I do occasionally get the premature reserve thing but other than that no performance or MPG difference whatsoever from before. I did think of the possibility of the filter restricting fuel flow being as the Ford filter I used was meant to have fuel pumped through it not gravity fed. With the rust I had in the tank I wanted the extra protection. I dodged the hydrolock bullet!
Maybe I got lucky with my choice of filters!  

[Chiefy]

I went ahead and installed a new petcock.  Filled the tank up and went 126 miles to reserve.  80 of those miles were 2 up.  So I was pretty pleased with that.  But it sure doesn't make sense to me.  The screens on the old one were not clogged.  Tube looked clear. 

Flippin' Magic, I guess 

[98valk]

I went ahead and installed a new petcock.  Filled the tank up and went 126 miles to reserve.  80 of those miles were 2 up.  So I was pretty pleased with that.  But it sure doesn't make sense to me.  The screens on the old one were not clogged.  Tube looked clear. 

Flippin' Magic, I guess 

just noticed u have two brothers exhaust, correct? u the org owner and installer of them? if not PO might have made changes to carbs, causing u the lower MPG. just thinking.

[Chiefy]

I went ahead and installed a new petcock.  Filled the tank up and went 126 miles to reserve.  80 of those miles were 2 up.  So I was pretty pleased with that.  But it sure doesn't make sense to me.  The screens on the old one were not clogged.  Tube looked clear. 

Flippin' Magic, I guess 

just noticed u have two brothers exhaust, correct? u the org owner and installer of them? if not PO might have made changes to carbs, causing u the lower MPG. just thinking.

My mpg is right in line with many others here.  I was just going reserve too soon, as if the screens were clogged or something.  PO put on the exhaust.  Dealer cleaned the carbs and installed new stock jets when I bought it.