Low Gas Mileage

[Guest Bill 2008]

My 2008 Venture went from 38/40 MPG to 23 MPG right after my 600 mile service. Can someone help me. I checked with the head mechanic at te dealership and he told me to keep my foot out of the carbs. HELP!!!!

[wkboard]

When my mileage was that low it was because one cylinder was not fireing. the coil wire had fallen off of that coil. If they changed plugs or messed with anything like that it could be the problem.

That huge drop does not sound like "driving style" to me.

[OB-1]

Other than the poor mileage, how is the bike running?

How many tanks of fuel have produced low fuel mileage?

My worst mileage has been 28-30mpg, but that's running fully loaded 80+mph into strong headwinds.

[V7Goose]

My 2008 Venture went from 38/40 MPG to 23 MPG right after my 600 mile service. Can someone help me. I checked with the head mechanic at te dealership and he told me to keep my foot out of the carbs. HELP!!!!

This is not good, and absolutely not normal. I agree that it is too big a drop to be riding style.

 

Does the bike still roll forward and back easily? Feel near the header pipes on all four cylinders and make sure they all heat up about the same speed and get to about the same temperature. Make sure the vacuum caps and hoses are still in place.

Goose

[stardbog]

Alan is absolutly right. It's very hard to hear diference between 3, and 4 cilinder fireing, only think is doesent go over 90 mph and suck gas like vampire. Last Year on the way to Ft Collins, one of coils are go bad, and bike can bearly make 100 miles out of gas tank. Wich is about 20 mils per galon

[BigShell]

I'll throw something out that maybe someone else with more knowledge than me can comment on. Can a bad carb-sync cause that big a drop in gas mileage? My understanding is that the manual has bad info on syncing the carbs. If the mechanic isn't aware of this, he may have taken a decent sync and made it bad.

[GeorgeS]

Start bike, Cold, feel for heat on all 4 pipes, Find the one that not getting Hot.

 

Go from there.

[Freebird]

It is true that the carb sync procedure in the manual is wrong. The correct procedure is listed in our tech library here. In addition to that, I've seen a LOT of bikes that just came from getting a carb sync at some dealers that were not even close. Either they are doing it wrong or just not trying to get it right.

[dogman]

My 07 also dropped its millage in half this year. Average 40 mpg to only around 20 to 23 mpg. I have not ridden too much but put 4 tanks in. I rode this past weekend pulling a trailer and filled up 3 times. I expect to get worse millage towing, but I wasn't towing for the other 4 fill ups.

 

My four pipes are hot and it sounds the same as last year with the exception, I am now getting that dreaded whine that I have read so much about. Wow the noise makes the radio not sound so good.

[jlh3rd]

is this disease spreading ?.......starting about last year, i began getting mileages of 33-36...where i use to get 38-42...i check my mileage after every fillup.ever since i've owned the bike......i just recently synched carbs, replaced plugs, all pipes are hot, checked every place i can think of for a vacumn leak...filled up a few days ago and mileage was 33...i have the tank mod so its easy for me to fill the tank to the same level........i really think that my smaller mileage drop is due to the ethanol...

[SaltyDawg]

I'm not sure what the problem is, but I can tell you with out a doubt I know when I drop a cylinder. It's not as noticeable in the lower gears but in 4th and 5th the bike will seriously hesitate and not want to accelerate. You will also start to smell raw gas. The exhaust pipes will also be cool as mentioned.

 

In answer to the question about a carb sync done wrong making the difference. Well I imagine it could be part of the problem. I was getting low 30's and did a carb sync and got into the mid 40's.

[hig4s]

My bike seems to be down on mileage too, was around 37 at freeway speeds and 44 slower cruising. Now around 31 freeway...

 

I bought a carbtune and did the sync per instructions here. It didn't make any difference, but then they didn't really seem to be off either. I'm planning on running some Seafoam through it to see if that helps. Doesn't seem to be a cylinder on mine as it still has plenty of power up in 4th and 5th.

 

Wonder if they have upped the alcohol content in gas over the last year.

[ddoggma]

I rode her off and on all winter. But not as much as last year. This spring I think I over seafoamed the bike and fouled a plug. Lost a cyl and had poor milage. Changed the plugs and got it firing again, but its still not taking the gas like it used to. Bike runs good ... ran better last year thou. It could just be me pushing the bike too much. But, I seem to remember her have a little more get up and go. Well now I need tires so I will live with it the way it is for now, Get tires then hope SkyDoc is well enought to do a sync and give the bike a look over. Down the road. On a side note, my BIL gave me some Marval Mystery oil. So I put some in to see if it would help...it did. Bike is almost to where I think she should be. But I need a Venture guru to look her over. I'm sure theres little things I havent done that would help alot. Like the wire mod or fuse block upgrade...etc. I cleaned some connection, but I'm guessing alot to what I'm doing with the electric stuff. My start switch needs cleaned too. Headlight is acting up. That could be messing her up I guess. Plus my fuses box is a mess...half new type fuses in line and some old ones on the old board look weak. That cant be good. I'll tackle it after the season if I make it...lol:dancefool: