[Bronson90]

All information and pictures from HMF Engineering forums...

KTM 525 and 450 are EXACTLY the same applications.

Stock Jetting:
Pilot 42
OBEKR Needle Clip 3rd From Top
170 Main Jet
Fuel Screw 3/4 Turns Out
Accelerator Pump Squirt 3 seconds

HMF Jetting:
45 Pilot Jet
OBEKR Needle Clip 4th From Top
170 Main Jet
HMF Fuel screw 2.5 Turns Out
Airbox Restrictor Removed

HP Gains

ALL STOCK = RED
HMF Slip On and re jet = BLUE

HP @ 4.5K RPM
Stock 22.0
HMF 27.6
Gain 5.6

HP @ 5.0K RPM
Stock 26.2
HMF 32.0
Gain 5.8

HP @ 5.5K RPM
Stock 30.7
HMF 36.2
Gain 5.5

HP @ 6.0K RPM
Stock 34.7
HMF 40.0
Gain 5.3

HP @ 6.5K RPM
Stock 37.0
HMF 42.3
Gain 5.3

HP @ 7.0K RPM
Stock 38.2
HMF 43.5
Gain 5.3

HP @ 7.5K RPM
Stock 38.6
HMF 44.1
Gain 5.5

HP @ 7900 RPM (Max Power)
Stock 38.7
HMF 44.3
Gain 5.6

Torque Gains

Stock = RED
HMF Slip On = BLUE

TQ @ 4.5K RPM
Stock 25.7
HMF 32.2
Gain 6.5

TQ @ 5.0K RPM
Stock 27.9
HMF 33.6
Gain 5.7

TQ @ 6.0K RPM
Stock 30.4
HMF 35.0 (Peak Torque)
Gain 4.6

 

[Bronson90]

The brushed aluminum finish is standard; numerous optional powdercoat finishes are also available for an additional charge.
https://hmfengineering.com/view_product.php...product_id=6264




HMF also offers a full system...
https://hmfengineering.com/view_product.php...product_id=6263

 

[dirtycarl]

On a cost per horsepower basis, is the full system worth the extra dough?

 

[vader]

Looks like the 525 could use a nice P&P and maybe a different headpipe to bring up some of those upper R's.

EDIT: HMF used to dyno their quads on stock tires, no slicks - but it looks like they used duro tires from a picture on their website.

 

[ohmsby]

I ordered the full exhaust this week I will let you know the results when it comes in

 

[Bronson90]

I ordered the full exhaust this week I will let you know the results when it comes in

sweet, i would like to see before and after dyno results if possible as well as some sound clips.

i have found that in my old age, my ears are more sensitive tha they were when i was younger...

my ears rang for two days after i last rode my ltr in november. mind that was with my helmet over a hoodie. i guess i am becoming a wuss...

 

[Bronson90]

Video compliments of HMFengineering

 

[ohmsby]

HMF full Exhaust is on I cant wait to ride I will try to get it on the Dyno next week. Also installed some Flexx bars.

We did an elka dune series shock install on Fungus's YFZ last nigh and wow what a difference it's no KTM

but wow those shocks are nice

 

[ohmsby]

Just got back from riding with the new HMF full exhaust and the butt dyno says whooa lots of low end improvement also running the JD jet kit with o-ring on spring

These bikes are geat off the shelf but IMHO the HMF exhaust really lets this thing loose

 

[nvmyktm]

I just purchased the full HMF system.
I have never jetted a bike before.
Can anyone offer help?
I do not see anything in the book that would help.

HMF Jetting:
45 Pilot Jet
OBEKR Needle Clip 4th From Top (this is Spanish to me)
170 Main Jet (I think this one is inside the 17mm bolt at the bottom of the carb)
HMF Fuel screw 2.5 Turns Out. (I see this step in the book)
Airbox Restrictor Removed (already done)

How long does it take to jet?
Thanks in advance...
My backround is in tuning EFI mustangs with power adders.

 

[powertechn2]

it takes as long as it takes lol, get it on dyno would be easier than ride jetting.

 

[pruno525xc]

i got the full HMF running 185 and 45 but third gear felt weird like it was too short. didnt have time to mess with it. any recomendations will be appreciated, and the same day I put the pipe on took it out for a test drive and broke my arm.... :blink: did feel a diffrence in other gears.

 

[Deadman]

If you are mostly stock, that 185 is way too rich.
I'd shoot for the 165-170 range, but I am assuming you have no other mods.........

 

[pruno525xc]

If you are mostly stock, that 185 is way too rich.
I'd shoot for the 165-170 range, but I am assuming you have no other mods.........

i was running a 180 before the pipe. when i bought the bike it was lean like at 170 then I dropped jd jeting in it put it to 180..take into consideration that i am below sea level.

 

[Deadman]

^^^^ they don't run very well underwater.

 

[pruno525xc]

^^^^ they don't run very well underwater.

so I should drop it back to a 170...175. Change the needle position. Please help have no clue how to jet

 

[dropcorr]

i was running a 180 before the pipe. when i bought the bike it was lean like at 170 then I dropped jd jeting in it put it to 180..take into consideration that i am below sea level.

What makes you think you were to lean? The bike comes with a 170 (well the 450xc does). I wouldnt think a stock 525 is too lean with a 170, could be just a little though.

 

[pruno525xc]

My buddy added da HMF slip on and didn't change a thing. He said it ran good. Maybe I messed up changing my jets. I guess i'll call HMF or JD. Jetting.......

 

[dropcorr]

My buddy added da HMF slip on and didn't change a thing. He said it ran good. Maybe I messed up changing my jets. I guess i'll call HMF or JD. Jetting.......

What did you end up with? Did you drop down to 170-175 range?

 

[pruno525xc]

Went back to 180, 45, and 4th clip. It ran a little better can't wait till this dam arm heals. So I can really enjoy dat new pipe. LOL.