Had a PC III and had the same problem 28 to 30 mpg hell at one point I only got 22 mpg could not tune it out of it either we tried several times. Changed to a SERT and now I routinely get 42 to 44 mpg with a stage IV 103". 30 mpg is not good....

 

Have you ever checked the cylinder pressures? Could be something (valve, ring,other) leaking pressure or causing the oxy censor to richen up things to compensate.

Mine got 40 consistantly bone stock, and now, with the new stage II bore kit w/cams etc installed, I get 42. Go figure! I am as happy as a hog wallerin in knee deep mud on a hot summer day.

 

Sounds to me you got one of the asswipes for a "tuner" like i saw in Daytona! I'd almost bet the farm whoever screwed up your bike did only full throtle pulls, no roller loading, and the low and midrange fuel numbers are off the charts. I ran a dyno for a looong time doing EPA certifications and WILL tell you flat out if you don't do partial throtle pulls and LOAD the rollers you won't get anywhere! I also preach that if you just do intake and exhaust mods and throw on some sort of a fuel controller you have just pissed your money away. I know this goes agains conventional thought, but if you don't match your cams AND heads to the increased airflow you've added more air and fuel, but still have a bottleneck in the SYSTEM that will prevent maximum output and fuel mileage. A BALANCED system will give you both power and mileage, and you can have them at the same time. It's a shame more of the so called tuners don't understand this. My current bike had one of these "wonder tunes" on it when i bought it. It had an S&S intake, an S&S fuel controller, and a set of Cobra 2/1 pipes, all suposedly tuned by a dyno shop. It got 28 MPG no matter how it was ridden and wouldn't run for crap at partial throtle. That's why the previous owner sold it with 7K miles on the odometer. I put it back stock, except for tweaking the fuel up .3% and it now gets 45-48 MPG CONSISTANTLY and runs like it supposed to. If you are going to mod your scoot, DO IT RIGHT!!!! Don't go half assed and wonder why it's not performing like it should.

 

The tune is only as good as the tuner. The PCIII is no less capable of metering fuel accurately than SERT, and has a -100 to +100% range from which to adjust AFR's. If you plug the right values into the PCIII it will also get 42-44mpg under the same conditions, or in my case up to 50mpg.

 

I am saying, I had a faulty one. not that all PC III are bad. It just so happens a SERT was what was on hand at the time. For some unknown reason it would go way rich after setting the AFR. No one could figure it out and I have gotten no answers as to why from the manufacture. They (Drag Specialties) did give me a PC V that I sold only because I had no need for it.

I should have explained it better in the first place.

 

No problem, I missed the part about the PCIII being faulty. It's too bad they couldn't have dealt with the problem before you invested in SERT.

 

here's my thread bacon..."https://www.hdforums.com/forum/touring-models/323418-fuel-mileage-gone-south.html"

 

Just read 'Xtreme Hawg's' thread....that sounds like a nightmare also.

My issue is that the bike has ALWAYS gotten 32 MPG. I had it bone stock until about 1500 miles...and was getting 32 mpg average stock. I heard two things at that time:

1: the bike needs to break in further (some say up to 5000 miles)
2: get a fuel management device

Got the PCIII, and seem to have a good map as I told the tech I have mpg issues (I will have to borrow a laptop to post the numbers from the PCIII program). Still, 32 mpg with the fuel management. I love my bike and did not get it just for mpg...but I had a V-rod before my bagger and it got BETTER mpg! (and yes, I keep a mileage book because of my issues).

 

Bacon I have the same bike as you do minus the copper paint and I ride the same streets and Hiways as you do. I now have 15,000 miles on the bike and it is completely stock. I average 42/43 mpg. I have gotten as much as 48mpg on a legal mph trip into eastern washington and on the return trip into a 30mph headwind it went down to 38mpg this was riding solo. So I would say your 32mpg figure is certainly low.

Tim

 

I get an average of 42 on the highway running 75 to 80. In town I get a consistent 30.