Fuel Consumption

[nickjtc]

Only replies from those of you who have totally stock bikes, please!!: carbs as set up by the factory, stock air filter and exhaust.

As I have mentioned ad nauseum the only thing that rankles a little with Stanley is the less-than-stellar (imo) fuel mileage I get. Anything from a low of 35mpg to a high of 42mpg over the 9,000km or so I have put under the wheels so far. That's Imperial mpg, incidentally. Never using over about 5500rpm and never faster than about 120kph. The po installed a K&N air filter, opened up both of the snorkels in the air box, re-jetted the carbs with a Dynojet kit, and messed around with the stock exhaust so that it is (I assume) louder than it should be.

If all this was in the name of increasing power, I don't particularly care. If it was just so that the exhaust note could be louder, ditto.

What could I reasonably expect for mpgs with a totally stock bike?

[ssevy]

My 95 has Mikunis, and everything else is stock. Fully loaded touring I get at least mid-40s. That is staying under 65 mph on back roads. On interstates running 75 mph, that drops closer to 40 mpg. By the way, these are US gallons. Mods such as your PO did usually whack the mileage pretty good. Other factors might he sticky calipers or low tirebpressures, but I am sure you already know that. Personally, having just rebuilt my Mikunis, I wouldn't mess with ecperimenting, as my bike runs great, and has a perfectly adequate powerband just as it is. I personally love thesectriples, and find them an excellent choice in both of my bikes.

[nickjtc]

Thanks for that. That's my point. 40's  mp(US)g equates to 50's mp(Imperial)g, which I would consider more realistic.???

[HeavyHustler]

Returned mine to stock from PO........my mpg isn't so great either.  However, I'm doing 80-90mph on the interstate which puts me under 40mpg.  If I were to nurse it I'm sure it'd get better.  Off-roading is ok on gas......I think.  lol!
The best out of a tank to bone dry I got was 242miles, with hwy and street miles mixed.

[threepot]

Mustang has 3 Steamers. How do his bikes compare against each other?

[nickjtc]

The best out of a tank to bone dry I got was 242miles, with hwy and street miles mixed.

242 miles = 390km. I am literally scraping the barrel when I hit 300km.

[nickjtc]

However, I'm doing 80-90mph on the interstate which puts me under 40mpg.

Which is still mid to high 40's mp(Imperial)g. I'd that!!

[nickjtc]

Obviously this is all relative, of course. A big ol' bruiser of a bike with carbs is never going to compete for fuel efficiency with the same bike fitted with fuel injection and electronic management systems coming out its wazoo. My '00 VFR800 consistently got 25+% better fuel mileage than a friends '90 VFR750 on the same trip, at the same speeds.

It just pains me that my econo-box people-mover KIA Rio four dour (admittedly with standard transmission) gets 25% better fuel consumption on the highway than Stanley does.

And, bottom line, I like the Tiger enough that all of its plusses (smooth, comfortable-ish, fast enough for me, rarity-factor, ease of maintenance [yes, really!! ] etc etc etc), far and away out do this one little niggle

[threepot]

It wont take/cost much to turn your bike back to stock? The carbs on my Steamer have the dual fuel feeds,probably off a Sprint,Daytona,I've just blocked one of the feed pipes. I've removed the 'witches hat' filters,and put an inline filter in. I fitted 42.5 pilots,and put in STD Tiger mains..105 . K&N filter,and STD airbox arrangement,but will  run with both open,Inc snorkels off my Daytona. But I have noticed an improvement in mpg since changing the carbs,over the std ones that were on the bike. I have no complaints with my mpg with that set up..50-60.

[nickjtc]

It wont take/cost much to turn your bike back to stock?

Frankly I have not done any research as to cost. I would imagine that the big ticket items will be stock mufflers...???

[threepot]

Just sort out the carbs. Don't think the mods done to the silencers will effect much?? My Daytona runs same with D&D silencers as with stock. Some UK Triumph parts shops selling 'new' carb sets for £420?

[nickjtc]

Just sort out the carbs. Don't think the mods done to the silencers will effect much?? My Daytona runs same with D&D silencers as with stock. Some UK Triumph parts shops selling 'new' carb sets for £420?

I have never 're-jetted' carbs before, but am assuming that once I know what the correct jet sizes are and the correct position for the needle it cannot be too difficult....? And blocking off the open snorkel will be easy.

The bike is 'off the road' as of today at midnight and the winter fettling time is not far away so I have plenty of time to putter on this before next year.

[Mustang]

I have never 're-jetted' carbs before, but am assuming that once I know what the correct jet sizes are and the correct position for the needle it cannot be too difficult....? And blocking off the open snorkel will be easy.

The bike is 'off the road' as of today at midnight and the winter fettling time is not far away so I have plenty of time to putter on this before next year.

USA and Canada models with Mikuni Carbs

Main Jets =105 (std)
pilots = #40 (std)
needle clip = middle notch (std)
pilot screws = 1 to 1 1/2 turns out from bottomed (std)
right snorkel capped (std)

the mikunis were never very good at gas mileage unless you keep the rpm's down .

all mileage figures are US GALLON

two laning under 60 mph you should easily be at 42 mpg

as soon as you step up the rpm on the interstate to run in the 70 mph range for extended time ,your mileage starts to fall to an average of 38 mpg
you run mikunis hard at 90 mph for extended time and you will be at 32 mpg or worse , not to mention that you WILL be pounding your valves into the head .

my 98 with the keihin carbs gets the best mileage of the 4 steamers
it will return 50-55 mpg very reliably as long as the rpm's are kept low .
you get her up to 80 on the freeway and the mileage takes a hard hit to around 38-40 mpg

the steamers were never very economical on gas , they are thirsty and only get worse when you vary from std .
dyno-jet kits were probably the biggest waste of fuel and money.

[nickjtc]

dyno-jet kits were probably the biggest waste of fuel and money.

Thank you for all the info. It will be interesting to see by how much the settings have been changed inside the carbs.

And, yes, I agree with you about Dynojet stuff. But it sure sounds racy doesn't it??

[fishnbiker]

I have a '95 which started out at 53mpg (Imperial). Over time & mileage it slowly dropped as low as 37mpg. A carb rebuild with new gaskets & O-rings brought it up to about 44mpg with a lot of mods done, oversize jets, K&N custom air box, Girly 3 into 1 header with a GSXR can. Still not enough, but much more HP, dyno'd at 101hp. After installing a set of rebuilt Keihins, I now get a consistent 47mpg with over 130,000km on it.

Rebuilding with new a new gasket set seems in order. Keihin Carbs would do even better. Maybe start cruising the wrecking yards?

Photos at http://fishnbiker.smugmug.com/motorcycles/