bad gas milege
Ultimate HDF Member
Joined: Feb 2008
Posts: 5,615
Likes: 9
From: Escondido, CA
Spark plugs, plug wires, dirty air filter, dirty fuel filter, bad tuner or tune, bad gas, carrying too much weight, burnt valves, plugged pipes, bad coil. I'm sure there are more causes but that's all I can come up with on a Sunday night.
Road Master
Joined: Oct 2009
Posts: 1,178
Likes: 6
From: N.C.
When I installed my PCIII fuel mileage went to crap on my bike. I was told by that I could maybe get a few miles per gallon more if I had the bike dyno tuned, however this was not guaranteed. So I just left my map on my PCIII that I downloaded from dynojets website on mine. I have not checked my exact mileage, but it seems like every time I ride I have to stop by the gas station and fill up.
Stellar HDF Member
Joined: Nov 2004
Posts: 3,156
Likes: 41
From: So Cal
What do you consider to be bad mileage ?
Everyone I ride with gets between 34 - 46 mpg depending on their riding style and mods to the engine.
Everyone I ride with gets between 34 - 46 mpg depending on their riding style and mods to the engine.
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Ultimate HDF Member
Joined: Oct 2007
Posts: 5,257
Likes: 6
From: Leander Texas
mine dropped also and i have found a few causes. at 50,000 miles my intake looked dirty. i cleaned it with berryman b12 carb cleaner and just sprayed all the parts in the throttle body clean. the other is that crap gas they sell now. the epa thinks cleaner burning stops pollution but not counting you burn more gas. wind. i rode back with tail wind and got 3 more MPG. i had a pclll at one time and it was acting like yours. i also did not have a smooth acceleration. the canned maps would not work for my bike. i had a dyno tune done and the mpg went way up and the hp and tq. when i looked at the comparison of the canned map and the dyno tune map some points were 17 + or - from the canned map.
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Extreme HDF Member
Joined: Nov 2006
Posts: 13,702
Likes: 38
From: Houston area
OP you need to get specific in your question. The above suggestions are all valid and there are probably more but without help from you there isn't much we can add. A dyno session is needed and is probably the cheapest money you will spend...I picked up 11 hp and #16 of torque on my Deuce that previous owner had Harley install PCIII when they did pipes and intake. I have been riding it without complaint 16K miles...it idles better, accelerates better, better throttle response, pulls hard to cutoff, runs cooler and lugs down better...notice a trend here? Mileage has never dropped below 42, typically 44-46 and as high as 49-50 on trip at reasonable speeds. Tune is the culprit more than likely unless coincidentally a plug or ? went south at same time...unlikely.
It is not a softail specific question and you might get more help in engine section of forum by posting more useful and more complete information there. The way you did it is like saying "why didn't my soup come out tasty?".
John
It is not a softail specific question and you might get more help in engine section of forum by posting more useful and more complete information there. The way you did it is like saying "why didn't my soup come out tasty?".
John
Road Master
Joined: Feb 2009
Posts: 923
Likes: 2
From: Back in NEW YORK!!
mine dropped also and i have found a few causes. at 50,000 miles my intake looked dirty. i cleaned it with berryman b12 carb cleaner and just sprayed all the parts in the throttle body clean. the other is that crap gas they sell now. the epa thinks cleaner burning stops pollution but not counting you burn more gas. wind. i rode back with tail wind and got 3 more MPG. i had a pclll at one time and it was acting like yours. i also did not have a smooth acceleration. the canned maps would not work for my bike. i had a dyno tune done and the mpg went way up and the hp and tq. when i looked at the comparison of the canned map and the dyno tune map some points were 17 + or - from the canned map.
I have V&H Staggered and SE Intake, bikes should be somewhat similar.