TDC Question

[FLboy]

I've been out to KTM talk and I have seen three ways to find TDC. Following is one way according to a weblink out there on adjusting valves (#3 below). Has anyone did it this way on a 450 KTM450EXC?? Does it work

Also, has anyone did it by 1) removing the Stator Cover (Maint. Manual way) or the other way mentined on KTM talk 2) where you watch the intake close and go back halfway and then adjust the exhaust and then vice versa? Which way is the easiest and most accurate?

If I remove the stator cover, do I need a new gasket?

*************** copy below ***************

3)

Remove the valve covers. Blow out the spark plug hole with compressed air and remove the

spark plug. Now watch the cam lobes and valves on the intake/carb side of the head. Work

the kickstarter until you see the lobes open and then close the intakes. There are two

TDC's on a 4 stroke, remember, so make sure you watch the intakes to determine when

you're on the comp stroke.

You probably won't be able to stop the cam rotation very precisely but that's okay. Stick

a straw or ziptie (not the locking end) down the spark plug hole to show where the piston

height is. Put the bike in 2nd gear and work the rear tire back and forth gently until

the piston height indicator shows you the piston is at TDC. Then run the crank locking

bolt in. Its shoulder should bottom out against the engine case without the thick copper

crush washer.

[coopou812]

I found TDC using the method in the Motopower DVD. Pull the vlave covers. Leave the plug in, but remove the wire. Kick slowly through until you see the exhaust valves depress then come back up. Kick again and the intake will depress and come backup. Check the rocker arms for a small amount of play. They should move a tiny bit back and forth. If the arms still have pressure applied kick just a hair more to bring the piston up, and check for play. The key is when there is play in both arms it's at TDC compression.

05 450EXC

[Dave Hopkins]

I would not kick the engine over with the spark plug wire off, that generates huge voltage and the shortest path to ground is to burn thru insulation inside the the coil.

There is no need to remove the spark plug, just pull the compresion release. Removing the plug wire on the KTM is the cause of many prolems that arise later, the wire cap is very hard to grip so most folks hand slides up and they end up pulling on the wire, this streaches the wire and pulls it loose from the cap, both a no no. If you must pull the wire off the best route is compressed air from below, second best is with long needle nose pliers.

Remove the valve covers, put the trans in 6th gear, hold the compresion release in with your left hand, grip the top of the rear tire with your right and turn it forward;

To adjust the exhaust valves turn it until the intake valve closes (there is some tollarance here, 1/2 closed would be perfect, just closed still OK.)

To adjust the intake turn it until the exhaust valve is opening (there is some tollarance here, 1/2 open would be perfect, just opened still OK.)

on the

[pelts79]

did mine the same as 812, but put the bike in 6th and rotated the back tire till one set (exhaust) was at the bottom and the other(intake) was at the top and check for play. Motosport video is well done.

[FLboy]

did mine the same as 812, but put the bike in 6th and rotated the back tire till one set (exhaust) was at the bottom and the other(intake) was at the top and check for play. Motosport video is well done.

Anyone have a video they want to sell?

[B12Teuton]

I just copy/pasted my post from KTM Talk:

Some people say getting to the valves is a pain, adjusting them is easy. I thought getting to them was pretty easy, finding TDC was made MUCH more difficult because I spent a long time screwing around with a straw in the cylinder, turning the engine in gear with the rear wheel, watching the sequence of intake/exhaust valves opening and trying to look in the stop-bolt hole at the front of the case.

Next time I'm just going to pop the side cover off and turn the cranck the propper way. All these "short cuts" are more of a PITA than anything else. Sorry to all the people that swear by them, but what a crock.

It took me longer to adjust the 4 valves on this bike than it does to check and adjust all 16 valves on my streetbike, which has the same locknut and screw setup AND requires you to advance the crack since you can only do half the valves in the initial position.

For anyone that is not really familiar with the RFS but does know how to wrench on a bike, do yourself a favor and do it the way they are designed it to be done. Pop off the side cover and advance the crank till it's in the correct position.

I'd rather sit next to the bike and slowly advance the crank and watch the valves rather than be F'ing around by the rear wheel, getting my hands dirty or busting my butt trying to turn the engine with the kick starter.

Finding TDC is easy watching the magnet. Finding the right TDC is easy watching the valves!

[coopou812]

Anyone have a video they want to sell?

I'm not ready to part with mine yet. I think the TT store has them for a good price.

[Burnrider]

DJH method using a 17 mm socket on the sprocket and setting the power handle at 1 0f 2 points:

KTM VALVE ADJUSTMENT WITHOUT FINDING TDC

Intake valves

1) Place transmission in 6th gear

2) Rear wheel off the ground

3) Hold the manual compression release

4) Place a 17mm socket with power handle on the primary sprocket and rotate it forward (CCW) until the exhaust valve starts to open halfway.

5) We are now fighting against the valve spring which wants to roll the engine back. To stop engine rotation, place the end of the power handle on the shift lever to hold the valves ½ way open.

6) Proceed to adjust the Intakes.

Exhaust valves

1) Remove the cable to the manual decompression lever.

2) Place a 17mm socket with power handle on the primary sprocket and rotate it forward (CCW) until the intake valves have opened and are 1/2 way closed.

3) As the intake is closing the engine will want roll forward PAST the ½ way point and close.

4) Use the 17 mm socket and power handle to rotate the sprocket backwards (CW).

5) Place the end of the power handle on the water pump housing to hold the valves ½ way open.

6) They are now opening instead of closing because the engine is turning backward (sprocket CW).

Still need a video?

[dezracer64]

Maybe for you it's a PITA, but for most others that have been working on KTMs' ,as well as other brands, it's the most widely used method. I don't know what is so difficult about watching a straw or Zip tie move up and down ? It used to take me aprox. 45 min to adjust mine using the method you desrcibed, but now it's about a 25 min. job using the 1/6 turn method. I won't even go into details about that procedure with you, as I feel you don't have the patience for it. Do yourself a favor though,before you "pop the side cover off", LAY THE BIKE ON IT'S SIDE.

I just copy/pasted my post from KTM Talk:

Some people say getting to the valves is a pain, adjusting them is easy. I thought getting to them was pretty easy, finding TDC was made MUCH more difficult because I spent a long time screwing around with a straw in the cylinder, turning the engine in gear with the rear wheel, watching the sequence of intake/exhaust valves opening and trying to look in the stop-bolt hole at the front of the case.

Next time I'm just going to pop the side cover off and turn the cranck the propper way. All these "short cuts" are more of a PITA than anything else. Sorry to all the people that swear by them, but what a crock.

It took me longer to adjust the 4 valves on this bike than it does to check and adjust all 16 valves on my streetbike, which has the same locknut and screw setup AND requires you to advance the crack since you can only do half the valves in the initial position.

For anyone that is not really familiar with the RFS but does know how to wrench on a bike, do yourself a favor and do it the way they are designed it to be done. Pop off the side cover and advance the crank till it's in the correct position.

I'd rather sit next to the bike and slowly advance the crank and watch the valves rather than be F'ing around by the rear wheel, getting my hands dirty or busting my butt trying to turn the engine with the kick starter.

Finding TDC is easy watching the magnet. Finding the right TDC is easy watching the valves!

[muggie]

on the right hand side engine case there is an allen head bolt with a thick copper washer underneath, remove the bolt and the washer, rotate the engine.[using whatever method you feel comforable with]replace the bolt without the cooper washer,while watching all four valves,when they look as if all four valves are closed,useing your hand screw in the alled head bolt,when the bolt is fully screwed in the engine is locked in tdc,then check your valves,remember to remove the bolt and replace again with the copper washer underneath.this method can be used on rfs and sxf models.

[Rodzilla]

Yet another method.

Do your valve check in conjunction with an oil change.

Drain oil as usual.

Remove valve covers, remove left side cover (flywheel side) with bike in nuetral use 17mm socket on the flywheel to rotate engine counter clock wise.

Watch intake vavles open/close as soon as they close, slowly continue to rotate through the compression stroke.

There is a metal "bump" on the flywheel that triggers the spark, the bump will be just past the ignition pick up when at TDC

THe right side (clockwise side) of the "bump" will line up with the left side of the left side of pick up.

(you can also pull out the locking bolt and shine a maglite in the hole and see the "slot" the bolt locks in to confirm if it makes you feel better)

[faceplnt]

Yet another method.

Do your valve check in conjunction with an oil change.

Drain oil as usual.

Remove valve covers, remove left side cover (flywheel side) with bike in nuetral use 17mm socket on the flywheel to rotate engine counter clock wise.

Watch intake vavles open/close as soon as they close, slowly continue to rotate through the compression stroke.

There is a metal "bump" on the flywheel that triggers the spark, the bump will be just past the ignition pick up when at TDC

THe right side (clockwise side) of the "bump" will line up with the left side of the left side of pick up.

(you can also pull out the locking bolt and shine a maglite in the hole and see the "slot" the bolt locks in to confirm if it makes you feel better)

I will 2nd that!

[smithpa68]

I've been out to KTM talk and I have seen three ways to find TDC. Following is one way according to a weblink out there on adjusting valves (#3 below). Has anyone did it this way on a 450 KTM450EXC?? Does it work

*************** copy below ***************

3)

Remove the valve covers. Blow out the spark plug hole with compressed air and remove the

spark plug. Now watch the cam lobes and valves on the intake/carb side of the head. Work

the kickstarter until you see the lobes open and then close the intakes. There are two

TDC's on a 4 stroke, remember, so make sure you watch the intakes to determine when

you're on the comp stroke.

You probably won't be able to stop the cam rotation very precisely but that's okay. Stick

a straw or ziptie (not the locking end) down the spark plug hole to show where the piston

height is. Put the bike in 2nd gear and work the rear tire back and forth gently until

the piston height indicator shows you the piston is at TDC. Then run the crank locking

bolt in. Its shoulder should bottom out against the engine case without the thick copper

crush washer.

This looks like Jeb's method. It is how I do it every time. I think it is super simple this way. The only thing I change is I use 6th gear instead. Somehow it just makes me feel better seeing the valves open/close in sequence. I keeps me straight.