Depends on which muffler I choose to run. Right now I have the 625SX unit installed. Idle's quieter than my KLX250S. Quieter everywhere except if I gun it. Then its as loud as my KLX nad Q4/QC insert.

If I run the OEM "hoover" can, the KTM is as quiet as the stock KLX exhaust.

I've owned the KTM for almost 10 years. It came with one of those old Supertrapp racing mufflers. I couldn't bear how loud it was.. took that muffler off and put it in the recycling bin.

If I plan on riding near suburban areas with houses, or anywhere there might be people/hikers/horses.. I run the quieter muffler.

 

Interesting, I run the '08 FE650E with the stock "Acro" and the '98 FC501 with a "Big Gun" - I admit the Big Gun on that bike is "over the top" loud.

 

Thank you for all the honest opinions and results, even dyno runs. This really gave a lot to consider. Nothing I've read here has convinced me to change anything in terms of motor.

I still need to duct tape my phone to my thigh and give it a top speed run with the GPS. I'll report back, hopefully in a day or two. Let's roll!

 

If I had a "stock" KLX that goes 97mph, I wouldn't believe anything I read in here either...lol

 

off by 8mph! I finally taped my GPS cell phone to my leg and without killing myself, drove the 20 miles to work today. If I tucked, it reached mid 90s, but on the GPS only read as high as 88mph max.
I was shocked at even low speeds it was off, but questioned how quickly the GPS could update itself.

At any rate, the bike does mid 80s, not mid 90s, per GPS.

 

That sounds about right, the speedo is known to be off by about 10%.

 

In fairness GPS won't update itself often enough to be accurate for anything other than dead straight lines.

If you went round any corners on that 20 mile ride then the GPS will underestimate your speed.

 

If you are happy with stock, and can stand the tall gearing and cold starting, keep it.
You will get better mileage than we do. but not doing 88mph!

 

I haven't had a lick of difficulty with cold starting, none. In fact, as I mentioned prior, it seems like its EFI the way it starts so easily.

As for tall gearing, have to run it this way, for freeway travel (20 miles one way to work). I don't use it for normal commutes, but have taken it a bunch just the same.

Mileage, yeah I averaged high 50s this last tank, no where near 70mpg!

 

atm i avg 60+mpg on my 09 EFI
only mod i know off atm is snorkel removed and i do about 50% city stop and go