Hello guys. I am a relatively new owner of a superhawk. It is a great bike, goes very well but the economy I get is 8.2 l/100 km (29 mpg) on the highway with 70-80 mph, no hard accelerations. Around town with traffic and lots of stop and go it gets 26 mpg. First I thought it was normal but today I looked at some threads in the forum and noticed most of you get 35-40 mpg!! I live in Europe and the bike is imported from the USA, 49 state version, with Factory pro jets 182/185 and a K&N filter. Pilot jet is 45, pilot screws 1 1/2 out. Exhaust is Jardine high mount. I checked float levels, adjusted the TPS from 820 to 510 (which made the economy a little better 1-2 mpg) everything seems normal... but the economy is not. Do you have any suggestions?

P.S I did not check the needle position but the spark plugs have a very nice light colour. Neither rich, nor lean

 

Do you have a brake that is sticking? (dragging)

Otherwise if it is jetted right and you are not riding hard, I don't know.. I have gotten in 20's for my MPG, but only when riding it HARD, otherwise upper 30's is more normal.

 

well from my experience even a half notch (washer) can fluctuate the mpg's by 5mpg. My buddy and I found this out, his bike had a miss that since his bike had aftermarket pipes we figured was too lean so we richened the mix a washer amount to get a 1/2 notch and not only did it not fix the miss but he lost 5 mpg for the next week he commuted on it. So if I was you I would try leaning the mix on the needle, just make sure you remember the original settings so if you fail you always can go back. Personally I think alot of folks go too rich with their settings thinking it helps. The butt dyno is a pretty deceiving thing. I have a race bmc filter and high flow cans run stock mains and a few notches richer on the needles, have a smooth throttle under all conditions and still see 40 mpgs regularly. So does my buddy, who's bike is actually running better more lean then stock.

 

Brakes aren't sticking for sure, the only reason for the bad economy seems to be the needle position. I guess I have nothing to add here until I open the carbs and see what is the needle (stock or Factory pro since the jets are Factory pro) and change the adjustment. Cornandp thank you for your advice I'll write again when I'm done to post the results!!!!!

LAZN, lower 30 is the best I could get so far

 

obviously the needle position allows gas to flow and it's height is important but in that equation is the size of the main jet. running 182/185 on a stock
motor always seemed very high too me ( i know others run it too ).

i'm running factory kit w/ 180/182 , needle position #4.

the color you stated on your plugs, light, suggests your on the money though.

tim

 

I was getting 38 mpg stock. I haven't figured out the milage this year as I'm afraid to. With my upgrades she's extra thirsty. Haha

 

well I guess I have nothing else left to try except lowering the needle

 

i usally get 'bout 29 to 31 mpg and i try to always go to the same gas stations

 

I know there is varience among bikes and riding styles, but 29mpg for 70 - 80mph highway just seems a bit low. On aggressive (street) riding I'll go under 35mpg but for the type described above I would typically see 42+.
I'm dynojetted by the PO so I do not know the jets, but she runs damn near perfect with my Microns, OEM filter and +2 rear.

 

Probably has a lot to do with the K&N and the needle position, and the size of the MJ's. I don't see the need of a 182F and 185R for the MJ's, not on a stock motor anyways!

 

I gotta say, ever since I have owned by '98 Hawk (8 years now) I have always been in the upper 20's mpg which has always been my primary complaint with my bike. I know it isn't going to get the mpg's of an inline 4 but I would like it better than my car. The bike runs great but I may need to take it to someone more experienced than myself to see what else can be fine-tuned to take the mpg's up a bit.

 

I just stated needle setting on the assumption you liked how it ran wide open. Those main jets do seem too big to me too. Also it was to suggest how even a little change in jetting can make a huge change in economy. Not only does how you ride have a big affect but so does the road type, city vs open highway. My city MPG drops to 30 if I am bouncing light to light. Again, IMO most people jet too rich for our bikes thinking more fuel more power, but it is always best mix most power. I guess it still just means you will have to pull the carbs and find out, you will get alot of opinions of jetting settings but what it comes down to is what you want, since that is MPG's I would put stock main size back in get an OEM filter then fiddle with the needle until it is on the leanest setting that is still rich enough the bike doesn't lean miss (backfire through the carbs). Thats what I did and I am pleased with ride ability and eco.

 

on a side note, I love google, doing that calculation used to be a total pain in the butt, now it's just: http://www.google.com/search?q=8.2+l%2F100+km+in+mpg

 

I like the WOT power, it is awesome! Before I adjust the TPS I could easily top out at 160mph, wheelies at second with stock gearing. Now after the TPS adjustment the acceleration feels even better.
These jets seem too high for me too, but I noticed guys from this forum getting better mpg with similar jetting that's why I started this thread..
In a couple of days I am checking/lowering the needles and if this doesn't help, we'll see what's next.. maybe the jets