99 IS, What mods can i do to improve my mpg?

[Memor86]

Hello guys, im thinking about selling my valkyrie, after riding with a couple of harleys and a bmw on a couple of long distance trips, the were fueling half of what my valk was taking. im riding two up, at speeds between 80-90 mph. i have just rebuilt the carbs with the cateye kit, all six were separeted striped and cleaned, i forgot to take note what jets it had. im running K&N air filter just cleaned, and stock exhaust. tires checked for the proper inflation every ride.

[Bighead]

Well I will say My street glide would get 55 mpg's at 85 Mph and my VALK will only get about 30 but I don't care I sold the Harley
You gotta choose whether you want to ride a classic or one that is a dime a dozen ( figuratively )
Do you want to conform to the in crowd or be a stand out?

[Steel cowboy]

What tire pressure are use riding on?
BUT.....
We don't have fuel injection so we won't get great gas Milage. What we do get is pride and enjoyment out of our rides. That's reason to ignore the small things. Like it was stated prior, V twins are everywhere, most boxer 6 cylinder engines today are hidden under plastic panels. A nostalgic Valkyrie is the only one out there with its balls out there for everybody to see and check out !!
100 hp and a minimum of 200 thousand miles of worry free riding.
I love my interstate.

[Pete]

If your IS is stock setup and tuned properly, the best it will ever get is 44MPG at 60 MPH.
And less MPG as speed increases - sorry.

[old2soon]

Yeah-did NOT buy mine for fuel economy. Your crusin 80-90 M P H fuel mileage WILL suck. I can still feel my limbs after a 600 or 700 mile day. RIDE SAFE.

[Memor86]

dont want you to think im some kind of cheap ass bastard. i live in Mexico, fuel here is very expensive.

[Bighead]

If your IS is stock setup and tuned properly, the best it will ever get is 44MPG at 60 MPH.
And less MPG as speed increases - sorry.

Hell  I couldn't get 44mpgs  riding 50 Mph and never getting over 2500 rpms

[98valk]

suggest u search some of my posts.
Honda used an inefficient exhaust system and mainly the ignition system. neither were designed with MPG in mind.  So far with my mods I get 40mpg average. straight hwy or more hwy miles than local I will avg 45+ mpg and that is at 80 mph. keeping it at 70 and I'll be close to 50mpg.

easiest way is to lower rpms in decending order Austone tire, a 205/65-16 size tire or an E3 tires which has the largest OD of the M/C tires.

[Dusty]

 From the old days.  A Dyna ignition module ( no longer made new but used one's are  around} Ground the white wire  when in top gear and cruising. I seem to remember the claim of 50 MPG at 80 MPH. Grounding the wire gives a  24 degree advance.

I hunted for the page but I think it is shut down.  Original poster is dead and the fellow that had it on his home  page  is a dead link.

Dusty   

[Memor86]

suggest u search some of my posts.
Honda used an inefficient exhaust system and mainly the ignition system. neither were designed with MPG in mind.  So far with my mods I get 40mpg average. straight hwy or more hwy miles than local I will avg 45+ mpg and that is at 80 mph. keeping it at 70 and I'll be close to 50mpg.

easiest way is to lower rpms in decending order Austone tire, a 205/65-16 size tire or an E3 tires which has the largest OD of the M/C tires.

not so familar with the search function, can you link me please? im running the E3 tires.

i have noticed that if i use the choke on cold starts the bike wont run without me having to give it throttle, is that normal? What could i have done wrong when i rebuilt the carbs?. does carb sync really affects the MPG?

[Pete]

If your IS is stock setup and tuned properly, the best it will ever get is 44MPG at 60 MPH.
And less MPG as speed increases - sorry.

Hell  I couldn't get 44mpgs  riding 50 Mph and never getting over 2500 rpms

I do it all the time with no problem, I suspect anyone could, if they wanted too.

[JC19]

I understand where you're coming from, but you can buy a whole lot of gas for the price difference between our bikes and H/D or BMW. Ride the bike you like best and do what you can to get better mpg, but two up at 80-90 is going to use a lot of gas no matter what you do.

[98valk]

From the old days.  A Dyna ignition module ( no longer made new but used one's are  around} Ground the white wire  when in top gear and cruising. I seem to remember the claim of 50 MPG at 80 MPH. Grounding the wire gives a  24 degree advance.

I hunted for the page but I think it is shut down.  Original poster is dead and the fellow that had it on his home  page  is a dead link.

Dusty   

ground wire only gives 10 degrees + or -.   I use a dyna with a modified OEM trigger wheel for 6 degrees.

[specialdose]

      Add a belly tank. Then you would still be riding the classiest bike. That would have to be waaaay cheaper than buying the HD and meeting yourself coming down the road every time you ride. It has been my experience that the HDs have a problem running sustained 90 mph runs, gas mileage or not. Maybe MoodyValk will market his EFI that he posted. At $1500 that would still be cheaper than the HD. Plus you would still be riding the coolest bike on the planet.

[Gideon]

Hello guys, im thinking about selling my valkyrie, after riding with a couple of harleys and a bmw on a couple of long distance trips, the were fueling half of what my valk was taking. im riding two up, at speeds between 80-90 mph. i have just rebuilt the carbs with the cateye kit, all six were separeted striped and cleaned, i forgot to take note what jets it had. im running K&N air filter just cleaned, and stock exhaust. tires checked for the proper inflation every ride.

I suggest you rent an HD from your local HD Dealer and take for a 500 or 600 mile ride.
When you get back home then make your decision to sell or not to sell the Valkyrie.
Happy Trails ! 

[98valk]

suggest u search some of my posts.
Honda used an inefficient exhaust system and mainly the ignition system. neither were designed with MPG in mind.  So far with my mods I get 40mpg average. straight hwy or more hwy miles than local I will avg 45+ mpg and that is at 80 mph. keeping it at 70 and I'll be close to 50mpg.

easiest way is to lower rpms in decending order Austone tire, a 205/65-16 size tire or an E3 tires which has the largest OD of the M/C tires.

not so familar with the search function, can you link me please? im running the E3 tires.

i have noticed that if i use the choke on cold starts the bike wont run without me having to give it throttle, is that normal? What could i have done wrong when i rebuilt the carbs?. does carb sync really affects the MPG?

carb sync, yes will help. search digi sync reviews.
 idle mixture screws should be 2 1/2 turns open.  can try 3 out for the 80-90 mph runs. the more the carbs can run off the pilot jets during hwy cruise the better mpg. u do not want to activate the needle circuit during cruise or mpg drops big time.

[Steel cowboy]

Sync'ing the carb's will only get you a better idle, at best up to 2000 rpm's. But once you kick in the high speed jets and open the carb's up, the sync'd carb's part of the equation is gone

[98valk]

Sync'ing the carb's will only get you a better idle, at best up to 2000 rpm's. But once you kick in the high speed jets and open the carb's up, the sync'd carb's part of the equation is gone

high speed jets? what are they?
these CV carbs have a pilot jet, needles and main jet.
sync'ing carbs help at ALL throttle positions for now all 6 throttle blades are equal for more balanced operations from each cylinder.

[Firefighter]

I just finished 850 miles in two days on my 2000 IS. 65 mph gps @3100 rpm, (spedo said 70), 35 mpg was the best. On the way home had some headwind and I was riding 70 (gps), mileage dropped to 29.

I have enlarged the tank neck vent hole and if the gas nozzle cooperates I can usually fill to the brim.

No wind or tail wind around 3000 rpm cruise control I can go 200+ miles before reserve. Mine has always had those numbers. The wind screen makes a big difference, the wind and twisting the throttle make alot of difference. Didn't know hardlys did that well.

[Memor86]

i would never ever ever buy a harley, man those this are lame (no offense). i love my bike but im really on the budget. i like and try to do all the maintenance myself and even fix things, so far i have been able to fix everything on my previous bikes without having to visit a shop, first i got a 1985 goldwing, then went for a 2002 vfr and then the valkyrie.

i used to love goldwings, but man most of the goldwings on mexico that i can afford are made between 1989 and 1999 and they are in bad condition missing lots of plastic covers and parts and i just hate seeing bikes missing parts. oh and not to mention some smartass people remove the OEM audio system to add a stupid car cd player just because it can play mp3. just to mention some of the stupid mods people do here on mexico. someone was offering to trade my valk for his bmw 1200lt but when he mentioned, like he was very proud of his mod. "I even added a car player that reads mp3 aint that cool?". damn.

well i've listed my valk at a really high price, if it goes fine, if not... ill keep enjoying it.

i haven't been able to find those 90º screwdrivers to turn the pilot screw, does anyon know of a home made thing that can be used to turn that without removing elbows and stuff?

[Steel cowboy]

I'm not going to argue pilot or idle jets as well as main or high speed, but you know what I meant. As far as throttle plates, when at idle the position will alow a lean or rich mixture. You adjust the the carb's so they are all supplying the even amount of air and fuel, at idle speed. Once the needles start to come up and out of the main jets or as the carb's transition to main jets the sync is no longer in the equation. Sorry if I confused you.
I have always done a visual pre sync of my carb's after a rebuild.

[cookiedough]

You should be getting 30 mpg or so at 80-90 mph.

Just keep the speed down to 60 and the mpg goes up to a whopping 35-40 mpg tops. 

I did not think HD's get much over 45 avg mpg have not heard of 50 mpg or over that on a HD.

If under 30 avg mpg,  that is not good and more than likely something is wrong even if you are into cracking the throttle wide open often. 

[98valk]

I'm not going to argue pilot or idle jets as well as main or high speed, but you know what I meant. As far as throttle plates, when at idle the position will alow a lean or rich mixture. You adjust the the carb's so they are all supplying the even amount of air and fuel, at idle speed. Once the needles start to come up and out of the main jets or as the carb's transition to main jets the sync is no longer in the equation. Sorry if I confused you.
I have always done a visual pre sync of my carb's after a rebuild.

I'm not confused. Never know what somebody means when they are using the incorrect terminology.
a sync is for the throttle blades which control air flow into the carbs. a sync works for all throttle positions ensuring each carb is allowing the same amount of air flow to enter. A sync does zero fuel adjustment to the fuel circuits.

[Memor86]

so, idle/pilot screw had nothing to do with the MPG? or it does? now im confused.

[Ricky-D]

so, idle/pilot screw had nothing to do with the MPG? or it does? now im confused.

Sure, it all has influence, but not as much as the hand that's on the throttle.

***

[98valk]

so, idle/pilot screw had nothing to do with the MPG? or it does? now im confused.

it does. if too small and incorrectly adjusted then more throttle will needed during hwy cruise, so much throttle that the needle circuit starts to come on line and mpg goes down big.  should be no more than 1/8 throttle on hwy whereas the pilot jets are supply all of the fuel.

[Ricky-D]

If you were to index your throttle, you would have more (better) information to produce a good solution.

***

[Valkpilot]

Nice animation on CV carb operation: https://www.youtube.com/watch?v=wyspAHrMbb8

[Paladin528]

What that animation does not show is that all of the circuits overlap.  The slow circuit still provides fuel when the throttle is open.  On some bikes that can be up to 50% throttle.  That is one reason the pilot setting is important.  You are still dumping fuel through it as well as from the needle.
Setting up a carb takes far more time than most people give it.  just because it runs well does not mean its running right.
On the Valk the proper setting procedure for the pilots can take well over an hour to do.  Most of us set them all at the same setting and call it a day.  That works but it isn't perfect.
Synching the Carbs only synchs the butterfly, The air Flow to ensure every cylinder is getting the same air charge.  That is only step 1 of "balancing" the carbs.
The procedure for setting the pilots is in the manual and has around 10 steps to be performed per carb.

[Memor86]

during long and high rpm engine braking my engine started to smoke, throttle closed, could that indicate that im running too rich on the low side?? when i did my carbs i think i set them to 2 and 1/4 out but i should probably check that

[Valkpilot]

What that animation does not show is that all of the circuits overlap. 

This one does: https://www.youtube.com/watch?v=-B-fLDOBqzo

[Ricky-D]

during long and high rpm engine braking my engine started to smoke, throttle closed, could that indicate that im running too rich on the low side?? when i did my carbs i think i set them to 2 and 1/4 out but i should probably check that

That's not fuel under those conditions but rather oil being sucked past the piston rings and/or valve guide seals.

***

[The emperor has no clothes]

during long and high rpm engine braking my engine started to smoke, throttle closed, could that indicate that im running too rich on the low side?? when i did my carbs i think i set them to 2 and 1/4 out but i should probably check that

I think that is indicative of oil getting past your valve guides.

[cookiedough]

suggest u search some of my posts.
Honda used an inefficient exhaust system and mainly the ignition system. neither were designed with MPG in mind.  So far with my mods I get 40mpg average. straight hwy or more hwy miles than local I will avg 45+ mpg and that is at 80 mph. keeping it at 70 and I'll be close to 50mpg.

easiest way is to lower rpms in decending order Austone tire, a 205/65-16 size tire or an E3 tires which has the largest OD of the M/C tires.

With that mpg at those speeds, you are in the 1% club for sure.  Better keep that Valk for is rare to see that kind of mpg ever.

My best ever was really low 40's mpg putzing under 55 mph for a long stretch.  Averages 35-36 mpg with worst around 30 mpg.  95% of my driving is 64 mph hwy. with stop/gos every say 10-15 miles or less.  One tank I tried my darndest to achieve daily driving 55-60 mph to get 40 avg mpg and never hit it only 38 is all.   For only 3 less mpg,  I will drive it like I stole it since bike can handle it. 

Sorry gas is so expensive where you live, but you bought the wrong bike to get over 40 avg mpg with 6 carbs/cyclinders although new goldwings do not get much better say 40 avg mpg. 

My suggestion is if gas mpg is a concern,  consider (if 2 smaller riders doing 2-up) a Honda CTX700 2014 used one.  I have read up on them and they get BETTER mpg than say a 250cc scooter between 60-70 avg mpg NO joke - that is GREAT mpg in a near 700cc engine, although is not super powerful or fast will get you to where you want to go.

I have my eyes on a used 2014 Honda CTX700 in red with Honda OEM red hard sidebags with corbin seat and taller windshield with 10K miles on it being 2nd owner already for 3.8K,  new one around 5K.  All it needs is a passenger backrest/flat rack on back for under 200 bucks and good to go.  Since is only about 1 hour away and if still for sale mid November, if he wants a sale before the snow flies,  I might go over and test drive and offer him 3.5K (especially if same OEM tires probably needing replacing soon) and then sell my 250cc scooter getting 63 avg mpg in the spring for say 1.5K since has new tires on it.   

[98valk]

suggest u search some of my posts.
Honda used an inefficient exhaust system and mainly the ignition system. neither were designed with MPG in mind.  So far with my mods I get 40mpg average. straight hwy or more hwy miles than local I will avg 45+ mpg and that is at 80 mph. keeping it at 70 and I'll be close to 50mpg.

easiest way is to lower rpms in decending order Austone tire, a 205/65-16 size tire or an E3 tires which has the largest OD of the M/C tires.

With that mpg at those speeds, you are in the 1% club for sure.  Better keep that Valk for is rare to see that kind of mpg ever.

My best ever was really low 40's mpg putzing under 55 mph for a long stretch.  Averages 35-36 mpg with worst around 30 mpg.  95% of my driving is 64 mph hwy. with stop/gos every say 10-15 miles or less.  One tank I tried my darndest to achieve daily driving 55-60 mph to get 40 avg mpg and never hit it only 38 is all.   For only 3 less mpg,  I will drive it like I stole it since bike can handle it. 

Sorry gas is so expensive where you live, but you bought the wrong bike to get over 40 avg mpg with 6 carbs/cyclinders although new goldwings do not get much better say 40 avg mpg. 

My suggestion is if gas mpg is a concern,  consider (if 2 smaller riders doing 2-up) a Honda CTX700 2014 used one.  I have read up on them and they get BETTER mpg than say a 250cc scooter between 60-70 avg mpg NO joke - that is GREAT mpg in a near 700cc engine, although is not super powerful or fast will get you to where you want to go.

I have my eyes on a used 2014 Honda CTX700 in red with Honda OEM red hard sidebags with corbin seat and taller windshield with 10K miles on it being 2nd owner already for 3.8K,  new one around 5K.  All it needs is a passenger backrest/flat rack on back for under 200 bucks and good to go.  Since is only about 1 hour away and if still for sale mid November, if he wants a sale before the snow flies,  I might go over and test drive and offer him 3.5K (especially if same OEM tires probably needing replacing soon) and then sell my 250cc scooter getting 63 avg mpg in the spring for say 1.5K since has new tires on it.   

will be even better once I put another set of heads on which were ported along with some R1 camshafts. These heads are very restrictive on the exhaust in stock form.