Earlier this year I did the 10 k tune up. Then the shop who did the work put a Moc2 air filter on my FLHT 09 STOCK. The bike started running leen ans deminish fuel mileage, like 70 miles a tank.
What I want to know : what will be the best remedy and keeping the Mac2. ?

I was going to add the Thundermax

 

I would guess that you'd have to have the ECM tuned also to adjust...was that done? Lotsa information in this forum about that, were it me, I'd just turn the job over to someone knows what they're doing, not my long suit, I'll guess it's not yours either...

 

what do you mean 10K tune up? do you mean 10k service?

"tune up" generally means servicing, tuning, altering the induction ( air/fuel) and ignition system.

1.) low MPG doesn't right away indicate the bike is running lean...more the opposite.

describe what mods have been done to the bike - in detail

and describe what driveability/ operation problems you are observing

more details, better answers

mike

 

Mike 10k service.
All that has been done to my bike with the exception of adding the Moc 2 air filter. A lot more air. The bike started running leen and the gas milage dropped.
Would going back to stock air filter be best or would dino ture return me the fuel milage. I am more interested in fuel mileage.

 

I'd be surprised if the air filter alone has resulted in a problem, unless the install was buggered.

alot of the Guys here use tuners etc.

I use nightrider.com XIEDS on my 09 FLHTC, they cost under $130

I also have a hi flow intake and exhaust...my mpg was 44 when stock and is 43 MPG now.

I've run this combination over 10,000 miles.

when you say the bike is running lean- what are you observing...and under what conditions, speed, rpms, load ( grade, passenger, extra weight) etc

mike

 

before the new air cleaner I was getting 250 miles to a tank on the open road around town I was getting 200.now I'm only getting a hundred forty seven to a tank around town maybe 200 on the open road.

 

This really doesn't make sense. The air cleaner may have made it run lean if no ECM changes were made. But that would tend to increase mileage not decrease it.

If the proper changes were made to compensate for more air, your mileage will decrease a bit.

 

My bet is oxygenated (winterized) Fuel. This time of year, my mileage drops as well and in the springtime when the EPA says it's OK to use a different blend, my mileage goes back to more normal levels. Most likely your bike is fine.

 

But that's a drop of >25%... I'd press the shop for an answer. I'd expect they know what they did, right?

 

I don't think that 25% is that drastic, I see 17% loss on my daily commutes to work 70 miles interstate round trip. So around town, my guess is I'd see just as much loss to winterized fuel at 25%. All of this is just a guess, but it's my story and I'm stickin' to it!