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repoman

Just got a 2007 KTM450exc

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Just got a 2007 KTM450exc. Im wondering on what I should be checking on it. It's been well maintained, not abused.

Stats. It has 4000 miles, and about 200 hours, has a recluse clutch and a pipe but internals all original. I bought it from the original owner and he rode mellow single track and desert, older guy more cruising I think. He changed the oil (filter every 3x) and cleaned air filter after every weekend, had the valves checked 3 times, needed adjustment the first two times, the last time no.

What should I be checking, in general given the hours/miles.  Runs and idles good,  the power is about right and it doesn't smoke or pop on deceleration. 

  

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Congrats on the bike.  Sounds like it was well maintained if the information you got is true.  Just stay on top of maintenance and you should be solid.

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Thanks, yes he was a good guy, he gave me 5 air filters he would keep prepped, to change after each ride...so Im really sure about the rest. The problem with the maintenance schedule in the manual is that the intervals are so short, like 20 hours rebuilds, Im not sure what to follow. The bike drives and run great, Im really stoked on it.

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Anyone that has 5 air filters for their bike probably takes very good care of it. With a well maintained 450 RFS, 4000 miles is nothing. Keep doing basic oil, filter, chain/sprockets, etc. The motor will go at least 10,000 before needing a top end....

 

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I’d change the oil a lot sooner than 3k though, I always try to do it around 500 miles. Sometimes I’ll skip the filters and not check the screens. Stay on top of the valve adjustments and make sure the air filter gets seated properly 👍

The Racing Four Strokes are pretty solid.

Congrats👍👍

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With 4k miles you are probably in good shape. Keep an eye on the counter shaft splines. They can wear on those bikes if they have a lot of street miles. If you use a high pressure grease on those splines it can help prolong thier life. Great bike. I had one. Sold it with 11,000 miles on it. I see it at D37 rides now and then, still running great. 

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14 hours ago, tntmo said:

Congrats on the bike.  Sounds like it was well maintained if the information you got is true.  Just stay on top of maintenance and you should be solid.

I agree with Tom. Though, I am not a KTM expert. I don't know any of the gotchas to BOLO for. Get out and ride!

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RFS=Bullet proof, just continue to keep dust and dirt out of it , even from the carb vents (overlooked easy to take care of with after market vent filters) , and keep her well oiled (no oil thread here) they are designed and designated RFS engines- Racing Four Strokes and use minimal oil , designed to be changed often as stated above.

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Congratulations! As stated before check the CS Spline Shaft. KTM no longer makes a replacement. I purchased a good used CS just in case. My 07 450 exc pounded out 12K miles before I rebuilt. Check lower shock bearing. Manual cam chain tensioner being installed helped my engine out from oil foaming scenarios getting chain slack.

Just Enjoy having a fine machine! . Oh Motorex makes a great oil just for RFS bikes 20/60 weight (no oil thread jokes please). 

https://www.motorex.com/en-us/moto-line/motor-oil/ktm-racing-4t-sae-20w60/ 

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Thanks for all your suggestions, I really appreciate it. The motor runs perfect but seems noisy Ive heard the rfs motors are like that. Could the cam tensioner need attention. Also the guy was using Rotella synthetic 5w-40 I think, Ive used it in a bunch of different vehicles and it seems to work well, is the Motorex worth the extra money? Had the rotella in my xr650l, harley dana and vw bus!

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10 minutes ago, repoman said:

Thanks for all your suggestions, I really appreciate it. The motor runs perfect but seems noisy Ive heard the rfs motors are like that. Could the cam tensioner need attention. Also the guy was using Rotella synthetic 5w-40 I think, Ive used it in a bunch of different vehicles and it seems to work well, is the Motorex worth the extra money? Had the rotella in my xr650l, harley dana and vw bus!

Sometimes  bikes with alumium skidplates transmit engine noise  ! Stick with Rotella 5-40 its fine . 

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36 minutes ago, repoman said:

Thanks for all your suggestions, I really appreciate it. The motor runs perfect but seems noisy Ive heard the rfs motors are like that. Could the cam tensioner need attention. Also the guy was using Rotella synthetic 5w-40 I think, Ive used it in a bunch of different vehicles and it seems to work well, is the Motorex worth the extra money? Had the rotella in my xr650l, harley dana and vw bus!

RFS motors often have loose countershaft nuts and corresponding woodruff key. They're aluminum and will loosen. One way to diagnose that issue is to place the front wheel against a wall or post, then, engine running and in gear, slowly release the clutch. If the noise changes (more than the corresponding drop in RPM) it's likely your culprit. Parts #15 and 16 in the attached parts diagram. Often found finger tight on many bikes. Only minor surgery required to get to it, but you'll want the clutch basket tool to tighten it- I have one if you want to borrow.

Remove nut, cleancleanclean all the oil off the nut threads and the shaft and the land for the woodruff key. Use a toothbrush with carb or brake cleanerUse a new key (if the nut's loose, the key will be hammered). I used red Loctite, despite the factory spec of 243 (blue).  Torque to factory spec. I don't recall if they're right or left-handed threads.

Now- DJ Hopkins used to have steel nuts made to the same spec, and they tend to stay tight. If it's the problem, it's worth an email or call to see if he still has any.

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21 hours ago, repoman said:

Thanks for all your suggestions, I really appreciate it. The motor runs perfect but seems noisy Ive heard the rfs motors are like that. Could the cam tensioner need attention. Also the guy was using Rotella synthetic 5w-40 I think, Ive used it in a bunch of different vehicles and it seems to work well, is the Motorex worth the extra money? Had the rotella in my xr650l, harley dana and vw bus!

  Oil tends to foam in the stock RFS  "hydraulic cam chain tensioner" at high RPM. Obviously foam allows the tensioner to compress thus loosing tension on the cam chain. 

  Yes, the extra cost of "lab created engine specific" oils like 20/60 4T Motorex is worth it in my opinion. Many will disagree and that is fine. Though why in southern California would any engine require a 5W oil? 5W is designed for Minnesota in mid January. Just does not make sense to me. If you want cheep oil to put in your 12 year old engine then at least start your weight rating as close to 20W as possible.

Here is a good option to quiet the engine cam chain noise and vibration in my experience; I have used this DJH version for a few years with quiet results and less cam chain vibration. 

https://www.ebay.com/i/123458420674?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=123458420674&targetid=543737969966&device=c&adtype=pla&googleloc=9030960&poi=&campaignid=1497308096&adgroupid=59509629482&rlsatarget=pla-543737969966&abcId=1139476&merchantid=6296724&gclid=EAIaIQobChMI0ezVvLeU4wIVTF8NCh0Mjg7CEAYYASABEgLkoPD_BwE

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My recent experience entailed horrible chinky chinky noises , changing to clanky grind grind, morphing to grind squeal clunk clunk bang screech. Time to rebuild.

Easy and not much diagnosis needed. 

Walk, whine, recover.

Write big check, repeat as needed.

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5 hours ago, repoman said:

One more question, how do i know when to rebuild the top end? 

Step one: disassemble entire motorcycle.

Step two: slap forehead and ask why I decided to do this myself.

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15 hours ago, Wierdrider said:

Compression or leak down test!

When a leak down test shows somewhere in the range of 8%-10%it's time to look at the top end. Maybe it will just need the valves worked on or maybe it will need rings or cylinder work. Maybe all of the above. After the leak down test more diagnosis is needed to determine what specifically needs to be done. 

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I live in carlsbad. I can do a compression test but prefer the leak down, where's a good place to have it done?

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Oh one other thing about how much is it to rebuild these guys? Just the top, also top an bottom? Thanks you all are so helpful, I appreciate it.

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45 minutes ago, repoman said:

Oh one other thing about how much is it to rebuild these guys? Just the top, also top an bottom? Thanks you all are so helpful, I appreciate it.

You have options- you can take it to a shop and have them do it start-to-finish, or you can pull the motor yourself and send it off to CAFlash or DJ Hopkins in a WalMart cooler. You'll save some with the latter and they're specialists- Hopkins is renown for this type of work.

Guessing a bit here- I'd estimate $800-1500, depending on what it needs.

SoHotMule might be able to narrow the estimate down a bit for you.

 

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8 hours ago, amgems said:

When a leak down test shows somewhere in the range of 8%-10%it's time to look at the top end. Maybe it will just need the valves worked on or maybe it will need rings or cylinder work. Maybe all of the above. After the leak down test more diagnosis is needed to determine what specifically needs to be done. 

+1

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3 hours ago, paulmbowers said:

SoHotMule

Just flipped back my wavy long hair! 

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