Converting a ktm 525 to 450

[montrose818]

Long time lurker, first time poster

I bought a very clean plated 525 from a friend, but its more bike than i want, runs hotter, etc. Ive read that its just a different bore on the engine - can I change it from a 525 to a 450 with just a cylinder and piston swap?

Thnx

 

[Animalmother]

I have nothing to add except anytime the topic of dirt bikes is brought up it makes me miss the days when 2 strokes ruled. I know modern fourstrokes are supposed to be all bad ass but nothing will dump you on your ass faster than an ill timed powerband explosion of a temperamental 2 stroke.

 

[evernoob]

Seems like you'd be better off swapping the entire bike. Like you can't get people interested in swapping their 450 for a 525?

 

[montrose818]

Not swapping. It is barely used, like new, with upgrades. It has to stay "in the family"

 

[Donk]

Fit an inlet restrictor of if it's efi get it mapped for less power.

 

[Keith]

What year KTM?

 

[montrose818]

07 I believe, last year of rfs

 

[Possum]

Yes a piston and cylinder should do it you may need a new head also bottom end is the same though. You will also need to re jet the carb.

 

[YotaAtieToo]

I have nothing to add except anytime the topic of dirt bikes is brought up it makes me miss the days when 2 strokes ruled. I know modern fourstrokes are supposed to be all bad ass but nothing will dump you on your ass faster than an ill timed powerband explosion of a temperamental 2 stroke.

2 strokes have been making a large comeback, mostly on trail bikes despite the (very) old stigma.

​​​​​​I recently rode an efi 300 ktm, holy fawk, what a badass bike. Incredible lug ability, but crazy (60+?) hp on tap. Plus because it's efi it's got separate oil and fuel tank. Can borrow straight fuel from buddies on long rides, or pull up to a gas pump. Oil is supposed to last 3-5 tanks of fuel iirc.

My father in law has a 525 and newer efi 500. Both are a handful anywhere but wide open areas. Maybe try to have the carb tuned to run a little more rich to cool it down? Not a carb guy

 

[montrose818]

yeah this 525 is too much. if i cant get it down to a 450, then i will convert it to supermoto. I dont want this much power on tight trails

 

[tracyb]

dont go effing up a nice bike for LESS power!


my kids bikes have an adjustable throttle stop, go that route..... if a riding buddy went this route i would endlessly fuck with it though.




really i cant get my head around the concept of too much power. maybe figure out a progressive spring in the throttle making it harder to hit WOT



shit one more thing- if you go with less power for the purpose of supermoto, as soon as it is supermoto'd then you will want the power back, or more top end... so maytbe just screw withthte gearing

 

[montrose818]

you missed it, if supermoto then stay 525, 450 for dirt

it is better to ride a slow bike fast, than a fast bike slow

 

[woods]

Perhaps switch up the gearing a little bit?

 

[TiTRD]

This is like removing a testicle to lower your sperm count.

 

[bdkw1]

​​​​​​I recently rode an efi 300 ktm, holy fawk, what a badass bike. Incredible lug ability, but crazy (60+?) hp on tap. Plus because it's efi it's got separate oil and fuel tank. Can borrow straight fuel from buddies on long rides, or pull up to a gas pump. Oil is supposed to last 3-5 tanks of fuel

They are nowhere near 60HP. My old KX was 62 at the rear tire. It felt like it was going to kill you. This has none of that feeling. It also has issues staying on the fucking kickstand.

 

[bdkw1]

yeah this 525 is too much. if i cant get it down to a 450, then i will convert it to supermoto. I dont want this much power on tight trails

Flywheel weight, make a tractor out of it.

 

[YotaAtieToo]

They are nowhere near 60HP. My old KX was 62 at the rear tire. It felt like it was going to kill you. This has none of that feeling. It also has issues staying on the fucking kickstand.

[]

OK, I looked it up, 51 stock. Not 60, but still damn respectable.

I'm sure the way the old bikes delivered the power had a lot to do with the murder feeling

 

[Arickvan]

Flywheel weight, make a tractor out of it.

Yep this and stock exhaust maybe throw a couple paper towels over the air filter for good measure

 

[ExWrench]

Not gonna' multi-quote right now but 3 posters above have your winning combo:

• Adjust cables to limit throttle opening to your preference
• Add flywheel weight for low-speed tractability & smoother power
• Gear down if bike won't go slow enough (smaller front sprocket is cheap)

I'd do all that^ before turning a 525 into a 450.
The 450 will be much the same animal as the 525.

If you wanna' pick through technical sections, add a Rekluse clutch to that list.

 

[bdkw1]

OK, I looked it up, 51 stock. Not 60, but still damn respectable.

I'm sure the way the old bikes delivered the power had a lot to do with the murder feeling

Waiting patiently for a big bore kit. And a desert tank.

 

[montrose818]

Its gotta go to a 450. 525s are known to run hot. First owner put fancy oil cooler but its still hotter than I want. Its jetted properly by a ktm tech. I appreciate the suggestions, already done gears, but I need to specifically lower it to a 450. Ive read its the same engine and crank, just different cylinder and piston. Can anyone confirm? Not sure if any ktm guys here

 

[woods]

Or you can just keep your dick in your pants.

Then again, I did sell off my FZ9.

 

[det107]

Its gotta go to a....

Turn in your man card. If it's too much bike for your frail body, forget putting this exciting KTM between your legs

If you wanna play, put a larger rear sprocket & dump-

 

[Redscram]

I have an 07 450 and have ridden an 07 525 many times. Neither of them is a race bike and there is not a huge difference in the performance of them. What pipe are you running? The stock pipe had a smaller pipe welded in the end to keep it quiet. The cost to benefit is not there for What you are doing. Both bikes fell heavy in the single track.

edit
If you dont have one get a fan kit

 

[montrose818]

has fan kit, oil cooler, it runs HOT, read that ita normal. I m in SoCal, it gets hot here.

 

[Stix]

Sell the euro trash and get a CR500 with flywheel weights. Pocket cash.

 

[Mudslinger99]

Sell the euro trash and get a CR500 with flywheel weights. Pocket cash.

He can't handle a 450 4 stroke and you want him to try to tame that Beast ?

His piss flaps would be up around his ears the 1st time the Power Band kicked In

This thread is the dumbest shit I've read in a while and I read a lot

 

[montrose818]

Brother, I am not going to cook the bike. You ever hear the phrase I mentioned, better drive slow bike fast than fast bike slow? Yeah you go take your cr500 in single track on side of the hill, but I will pass thank you.

I dont want to sell it because new frame design, first year street legal, and last year of RFS engine make this is rare bike, especially in this condition. Plus my buddy sold it so I could ride it, it would be a dick move for me to turn around and sell it.

Guess Im on my own. Its going to boil over riding single track, even more if I gear it down, so maybe get a smaller bike for dirt and sumo this sucker then

 

[TRINDU]

Why didnt you post this on the site with more P?

 

[montrose818]

Why didnt you post this on the site with more P?

Im part of the herd, duh.