MPG help !

[scooperhsd]

Ok - I will be the first to admit I did very little riding last summer (maybe 1 fillup ?) (back troubles).

However, my 2 fillups this riding season (mar and Apr22) were both down at 16-17 MPG, whereas in the past I usually get ~25 mpg.

Any thing I need to look at, or send to the shop ? If anything, since I'm kind of rusty, I'm not quite as hard on the throttle as usual. and both rides were mix of highway / suburban roads.

[LadyDraco]

I  hope  ya  checked  your tire pressure.
Maybe  put some  B12, or  seafoam, or MMMO, and  always Star Tron in the  fuel tank

[old2soon]

    Should you still ride the stock petcock with That Little riding I'd suspect the rubber diaphragm is no longer in good shape. You need to rebuild the stock diaphragm. Honda calls it a cover set. Have you got someone to ride behind anf if Yes tell em to leave windows down and check for a STRONG gasoline smell behind you on the Valkyrie. Last time my went kerflooy the strong gasolins smell from my Valkyrie wuz the give away!  Let us know what you fined please. Might look in between the carbs and see how good or bad the fuel hoses are. These Valkyries git vindictive when NOT Ridden! Ask me HOW I KNOW!  RIDE SAFE.

[scooperhsd]

Actually - when I bought it, my Valk had (and I replaced it with) a Pingle fuel petcock. I do usually smell gas in the garage where I keep it. Fuel - I gas up at QT using Non-ethanol regular (87 Octane), with no additives. I had thought about checking the tires pressure, but it didn't "feel" low.

Edit - just checked tire pressure - LOW (15 PSI front) and 20-25 PSI rear). Will take care of this and see what happens.

[LadyDraco]

That's  pretty low, 
She should  have  felt like   sluggish with that low  of  pressure!
Always  check the  tires if  they are  sitting ..

[John Schmidt]

~25 mpg?? You should be getting nearly 10mpg more, my trike gets more than 25. My 2 wheel Valk got in the upper 30's when I traveled with it. Low tire pressure will affect mileage but seldom 8-10mpg. There's something else needing attention, and if you can smell gas in the garage I darn sure would start looking.

[old2soon]

     Have you ever replaced the fuel lines? Carb intake O rings been replaced? Does it pop and fart on decel? Something anything moved into the air filter box? Are the carbs properly synced? I Know I'm missing stuff from this check list BUT at least it's a Start! RIDE SAFE.

[Cracker Jack]

Sitting for long periods can/will result in lower mileage because of evaporation. 

[Hook#3287]

I kinda doubt the low tire pressure is the only reason for your low MPG, but it definitely is a part.

As stated, you should be seeing numbers in the mid 30's.

When ever my bikes sit for more than a week, part of the pre-ride check is tire PSI.

It's a habit I got into and has proven to be a good one.

If you're smelling gas when parked in the garage, maybe not parking in the garage is prudent.

If you can't locate an obvious fuel leak, then the gas must be going out the exhaust and a spark plug test is advisable.  But I can't think of how that would happen and not show other symptoms.

In your situation, I would run a couple tanks with B-12 and do a MPG test before and after, assuming no fuel leak.

No change, more investigation.

[LadyDraco]

Just a  good  tune  up could  be  in order too...
Check air filter, drain drool, oil change , make  sure  your  brakes are  not dragging (rear)
Make  sure  mud dabbers  didn't  fill any  drain lines or  T fitting..
tap the  carbs, maybe  one  is  sticking a  bit. Make sure you were  not riding with lightly choked.
(you said you were rusty)
Do the  plastic  sliders feel sluggish ? when you throttle?
   run some  MMO in the  fuel, that helps  lube them.
I  can get that with TheBeast. 
When was the  last time  ya  changed  the  spark plugs, or  check the  Valve  settings.

I would  also just  let every  thing relubricate a  bit.. Before  I  start  looking  deeper..
It sat a  whole year just about !

[Serk]

Any chance the choke (Enricher, whatever) is on, either actually or stuck maybe?

[scooperhsd]

Well - the tire PSI  was below 20 on both.  That has been corrected. It is MUCH easier to back it back into the garage...
The enrichiner is 100% functional. The engine revs quickly when called upon to do so.

Oil change was done after yesterday's ride, along with filter.

getting much more indepth into the engine possibilities is not in my wheelhouse - will get to a shop that will work on old bikes in the next 30-40 days. I can't remember ever changing spark plugs since I bought it, nor having valves checked, so I think that will be a good idea. Later this week (maybe the weekend) will take it out on another ride to see if the tire pressure helped.

[sandy]

Where are your pilot screws set? Tech manual calls for 1 3/4 to 2 turns out from lightly seated. It’s popular to open them more but it has an effect on MPGs.

[bassman]

Well - the tire PSI  was below 20 on both.  That has been corrected.

Corrected to what pressure?   40psi front and 42psi rear is what I liked

[scooperhsd]

Well - the tire PSI  was below 20 on both.  That has been corrected.

Corrected to what pressure?   40psi front and 42psi rear is what I liked

40 and 40

[Jess from VA]

Running below 20 on both tires is a bit of an embarrassment Scott.   

But that migtht be one MPG.  It's something else.

Get new plugs (Nippon Denso, which I guess is now just Denso) decently gapped right away.  Little dab of dialectic grease on the threads.  Snugged not torqued.  Any corrosion in the wire plug caps cleaned off.

The air cleaner is next.  Tank off (hopefully not full).  This is a likely suspect.

[cookiedough]

Well - the tire PSI  was below 20 on both.  That has been corrected.

Corrected to what pressure?   40psi front and 42psi rear is what I liked

40 and 40

I go 38 to 40 psi front, and 44 to 46 psi rear (or 42 if a lighter feller)

much under 30 mpg is very bad not normal for most of us.   my 98 cobra exhaust only gets 32 to 33 mpg but my stock I/S gets 35 to 38 mpg     Never ever seen 40 mpg nor under 30 avg mpg

[scooperhsd]

I took it out for a test ride this morning (after inflating my tires  ) and actually made 27 MPG. I still took it to the Shop that Willow had referred me to so they can do a full service including what all the suggestions have been so far. we'll see what they can do.

[Beer van Huet]

Sounds like it doesn't hurt to check your vacuum lines for leaks. Especially near the end where they connect to the carburetor inlets. And synchronise your carburators.
Both will increase your mileage.

[Robert]

Of course it could be the floats, how about some Techron in the gas.

[scooperhsd]

Update - the shop has done alot of maintenance that I didn't do since I bought it in 2017, but they broke a bolt on the rightside valve cover that he has to get from his salvage yard. I should have it back wednesday Jun 5.

[Hook#3287]

but they broke a bolt on the rightside valve cover

Been there, done that, easy fix.

9ft lbs is not much and easy to pass.

[98valk]

A few MPG tips FYI Updated

https://www.valkyrieforum.com/bbs/index.php/topic,122617.0.html

[scooperhsd]

but they broke a bolt on the rightside valve cover

Been there, done that, easy fix.

9ft lbs is not much and easy to pass.

It probably is, but the owner runs a motorcycle salvage (Willow knows him well - that's how i got hooked up with him.) As long as I get it back wednesday I'll be happy.

Motorcycles are like any other ICE engine - they aren't happy if they don't get run enough, and last summer I flat out abused mine by neglect due to my medical issues. I'm hoping to get lots of riding in this summer.

98Valk - I looked at your thread - interesting stuff, but I'm not enough of a mechanic to implement alot of it. I'll settle for keeping it maintained.

[scooperhsd]

Bad news - The bolt that broke off did so flush at the head fitting for it. So -
1st - they will try Easyouts to get it out / put new threads in / new bigger bolt.
or if that fails -
2 - take head off and take it to a machine shop and go from there.

[scooperhsd]

Good news - got it back this afternoon. Ignition was left on, so dead battery.

Bad news - I'm beginning to think they messed up my wiring for the Aux terminal - my GPS  doesn't want to power up. Will find out more tomorrow after battery is charged.