KTM Frame

[tschisi]

Hi!

Has anyone ever tried to put a k5 engine into a KTM EXC Frame?

[jonny500]

why not buy a ktm 380. i had 1 and they are beasts

[tschisi]

Because that would be 120cc too few 

Seriously, with a street legal frame i could make use of the k5?s power.
That would make it to something more than my "second bike".

[PowerFiend]

I haven't seen a KX, but have seen it done with a CR500.

[tschisi]

I read some CR500 into KTM threads and it seems that the honde engine nearly fits as it would be built for it.
The rear engine/swingarm/frame mounting bolt and the pipe fit without any modifications, just the two front and the upper engine mounting brackets need to be modified.
Also the head with the spark plug should have clearance.
So the question is if the dimension of the k5 engine are similar to the cr500.
Would be great, but i guess the chance is small?!

[Kracer]

Hey Guys--
  I have just completed what I consider a "Top Shelf" project of putting a KX-500 motor into a 2006 525 sx KTM frame.  I have owned 2 Service Honda Cr-500's in the past.  I was very disappointed with how both of the Service Honda's handled.  The bikes (Service Honda's) gave me zero confidence.  This last fall I decided that i needed to start with a frame that gave me confidence to start with.
  My style of riding demands a bike that is very much a "power slider".  And, what gives me confidence is a bike that is stable in the rough, and on dry, slick turns that the front wheel sticks, while I can bring the rear wheel around predictably, without having the bike high-side, unpredictably. 
  I purchased the 2006 KTM 525sx last year off of craigslist, with the bike only having 25 hours on it.  I had Jeff Slavens do a high end valve job on both the Forks, and the shock.  I have ridden the 525 alot last year to fine-tune it, before i had to begin purchasing KX-500 motors.
  I had Jim Bennett at Racer's Edge in Lakewood, Colorado totally rebuild one of the '99 KX-500 engine's I had purchased.  Jim has done several motors for me in the past.  We always try and build a motor that reduce's the 500's vibration, and to do mod's that create reliability, in any of the big two-strokes.
  I rode the KXTM for the first time this last Sunday, March 20th at Milliken, Co.--Which was a fairly technical track--I was very suprized just how different the two-stroke motor "weighted" the suspension, compared to the 525 4-stroke.
  This is a very easy conversion to do.  The motor fits into the frame, like it is done at the factory.  You do not have to cut the downtube yoke at all.  Even the chain guard that covers the countershaft sprocket, on the engine, accepts the stock chainguard from the KTM frame--I love the small details that workout--Don't you guys??  I have owned 2 CR-500's, 2 KX-500's plus 3 KTM 380's in the past, Plus the 2 Service Honda's that I mentioned earlier.  I loved the 380's, but, however i found that the primary clutch shaft bearings to be particularly fragile, in the 380 motors.
  I'm fine-tuning the KXTM more each week--I'll try and post some photo's of it tomorrow--Sorry guys, this is my first post on here--So bear with me--KRACER


 

[Motorrad]

That is one heck of a first post!..

I cant wait to see pictures of this...   Love the KTM ergos... Love the KX500 motor...  Whynot

[ID KX500]

Outstanding!

[Kracer]

Hey there,
  Here are a few photo's of the KXTM-500, that I took today--Now I'm going to go ride it--Kracer

       http://s1139.photobucket.com/albums/n541/Kracer1/KXTM-500/

[Motorrad]

Hey there,
  Here are a few photo's of the KXTM-500, that I took today--Now I'm going to go ride it--Kracer

       http://s1139.photobucket.com/albums/n541/Kracer1/KXTM-500/

I think I'm in love.

[tschisi]

That?s exactly what i was talking about. 
The bike looks great, although i would swap to the two-stroke fuel tank.

Could you please post all the neccessary modifications?
Is that a cr500 pipe?

[Kracer]

  I did try both a 250sx, and a 250sxf fuel tanks.  Neither of them fit nearly as well, as the 525 tank.  Plus the 525 tank carries the fuel much lower than the other two tanks.
  About the mods--On the engine, drill out the rear swingarm pivot mount through the cases to 17mm.  And we cut off the top spigot the the head, and changed the angle, rewelded the spigot.  This was very sano, that way the stock KTM 525 radiator hoses could be used.
  On the frame--Cut off both the front motor mounts, and the bottom motor mounts, rewelded those mounts to accept the KX-500 engine.  Cut off, and re-welded the mounts on the sub-frame to accept the KX-500 silencer.
  The pipe is a pipe that I bought from Service Honda, made for their KX-500AF--Note:Service Honda did not want to sell me the pipe.  (And they weren't very nice!)  The only reason they did is because, I had purchased a bike from them in the past.  I called FMF to see if we can buy pipes directly from them.  They were very nice, but informed me that they sell the pipes to Service Honda only.--Maybe if we all call FMF that they will start selling us the pipes direct??--Just a thought--
  I weighed both entire bikes, before and after the motor conversion--The KX-500 motor is 15 pounds lighter than the KTM 525 motor!  The stock KTM 525sx weighed in at 244lbs--And after the conversion the KXTM weighed in at 238lbs.--The FMF Gnarly pipe is quite heavy for a 2-stroke pipe--And on both bikes I do use titanium motor mount bolts, shock bolts, and a swingarm pivot bolt.--These I purchased through Mettec--Great guys there--Kracer

[PowerFiend]

Nice work. Though I do like the KTM's with orange frames like that, I think you should redo it in Green with matching graphics. 

What year/base bike Service Honda's did you have for reference?

[tschisi]

Would be interesting if the cr500 pipe also fits this combination.
I think the k5 pipe is difficult to modify to fit this frame...

[Kracer]

I had both a 2004 CR-500AF, and a 2007 CR-500AF.  I felt like both frames were way to "small" for the 500 motors--I spent big money on springs, suspension work (Through MX-Tech) and considerable time testing these bikes--Plus we had to do alot of work to the bikes, when we recieved them from Service Honda--Chain alignment--
   To be honest,(And I know this is going to offend alot of people out there, especially when they spend big money on their AF conversions) I don't think that I have ridden any aluminium framed bikes, that I would call "good handlers".  Especially when mated to a 2-stroke motor.  I have ridden some 4 stroke motored aluminium framed bikes that I thought were decent, but not "great".--But, this is my opinion--And, what I have noticed through my own trial, and error.
  Like I said in an earlier post--to me it's all about confidence.  And what I think is a good-handling motorcycle, some-one else might think is junk also.--Kracer