With the dfo adjusted properly will I get better gas milage or worse than before I installed the dfo

 

Like always, it depends,if your engine is running lean now and you "properly" tune it to bemore rich, your mileagewill probablydecrease or vice versa. Also, what is a "proper" tune, if you ask severalexpert tuners you will get several answers. Some engines, different combos and different tuners useor require differentfuel mixtures.Some tuners will bias an enginemore rich during cruisebecause the engine runs cooler at the expense of milage. Unless we are onlytrying tominimize polutants, there is no"proper" A/F ratio or tunefor every engine.

 

In theory, you shouldn't get better mileage since the unit only adds fuel. However, if you have it properly tuned, you also shouldn't loose any mileage either. I run a DFO and averaage in the low 40's for most riding....that's even with my lower 3:37 gearing.

 

The Revtech, as said, only adds fuel. But, since I've read that the bikes are tuned a little lean from the factory, you don't always need a fuel manager that will add and subtract fuel. So, if it adds fuel, you will loose a few miles per gallon, but not many if it isn't tuned too rich

 

+

Same here. I probably lost 2 mpg with the addition of the DFO which is 10-12 miles per tank.

 

I have just bought a 2004 Road King with a Rev Tech DFO. It has had a screaming eagle upgrade. (cylinders pistons breather and cams). and slip on pipes. This was all installed at HD. Does anybody have instructions that came with the DFO. It runs good but I would like to know a little more about it and how it works. Thanks

 

It's a good product.

 

http://www.harleyhog.co.uk/dfo.htm
also,
http://www.dobeckperformance.com/

 

I have one more question about the dfo. If the dfo goes bad will the bike just quit or will it run on the EFI system and burn a hole in my piston. The bike has not been remaped. Thanks

 

Neither, it will run just like you removed it, i.e. it will run on the original EFI module.