How to set motor at top dead center (tdc)

[fasterblaster02]

I need to know how to set the ktm motor at tdc so i can set the valves. I have the service manual and it never specifically says how to do it. Thanks for any help.

[Evasiveone]

Do not bother with the TDC method of adjusting the valves on the RFS motor but rather use the intake closing and exhaust opening method.


I explain it here in this thread, although it is now missing a lot of the pictures it is still pretty self explanatory. KTM RFS valve adjustment (http://www.polarisriders.com/index.cfm?action=thread&catid=99&topid=438&thrid=42059)

[sheriff525]

FYI
Doesn't work if you have a rekluse clutch.

You have to take out your clutch and install stock then adjust the valves.

Is it true that the valves don't need much adjustment after 40hrs?

Maybe for those considering a rekluse in the future can wait till 40hrs.

[fasterblaster02]

Ok that is good info and i tried it, BUT now i have a tick in the top end that wasnt there before. Any ideas as to what i may have done wrong?

[powertechn2]

most likely, you set at least one valve too loose, now you have valve clatter.

[coalrat]

Easy way to check if your at TDC,

take your plug out, shine a flash light in and watch piston comming up, stop it when it gets to top before rollback.

If valves are all tight, piston goes down and back again, should be loose this time, at least most of them.
set the valves. .005

Theres a way you dont even need a feelers gauge, works just as good.

[SSJEFF]

keep in mind the decompressioner on the exhaust valves. if you have ever had the cam out you will kow what I am talking about.

The Rekluse makes it a lot harder to adjust the valves on a fresh motor especially. Have to take the clutch cover off or bump it with the starter and it spins way too fast.

[Polaris 450MXR]

On the very front of the motor doyn by the motor mount area, on the pass side of the quad there is a bolt that is like 12mm or 13mm take that out spin the motor to top dead center and insert tool or a long threaded bolt that will hold the crank in place and makes everything easy - new cam - piston timing chain - make necesary repairs remove threaded rod or bolt and reinstal the bolt that was removed.....Done!

[fasterblaster02]

Ok thanks for the info. I need to know one more thing, though. Does the oil need to be drained to take off the ignition cover and take the bolt out to lock the motor?
Thanks for the info guys.

[fasterblaster02]

another quick question, how do you guys with the IRS have your front sprocket set up? The manual says put the spacer on the inside and also the high collar to the inside. I have it that way and the chain dosent seem to be running that straight and it is making a "clunking" noise. I just put new chain and sprockets on.

[SSJEFF]

Originally posted by fasterblaster02
another quick question, how do you guys with the IRS have your front sprocket set up? The manual says put the spacer on the inside and also the high collar to the inside. I have it that way and the chain dosent seem to be running that straight and it is making a "clunking" noise. I just put new chain and sprockets on.

You will get the clunking noise if the chain is not at the right tension and is too loose. It hits the frame and makes that noise.

I also know what you are talking about with the spacer. Some guys have switched it to the other side.