How do I find TDC?

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Joined
May 3, 2024
Messages
4
Location
Montana, United States
Hello I’m fairly new to Husaberg’s I picked my first 1992 Husaberg FE350 a couple days ago and since it’s a used bike I want to check the valve clearance. But I’m running into a couple issues. First issue is it’s the first gen engine which has no timing marks for TDC. So I thought I could gat a engine stopper tool (the one that goes in the spark plug hole and stops the engine just before tdc) but the issue with that is there’s so much drag on the cam and valve springs that it would force the piston to jam full force into my engine stopper tool and might risk damaging my piston or spark plug threads. So just wondering if anyone else knows how to find tdc on the old first gen Bergs. Any info is much appreciated thanks!

~MattIMG_1219.jpeg
 
Here is what I consider the best tutorial for adjusting the valves written by Daleo. I use the 1/6th turn method instead of using a feeler gauge though:

How about this for starters?

Get an offset feeler gauge made for adjusting valves. They come with two feelers, one on each end, you need the one with a .004" & .005".

Then try this procedure:

Read this all the way through before using this as a guide.

with the vlave covers off, the ignition cover off,the spark plug out, push the motor through several times watching the intake and exhaust valves open and close.

You will notice that when the intake valves open, the piston is going DOWN on the intake stroke. Then, as you keep pushing on the kick starter the motor will kind of fee wheel, the intake valves will snap shut, and you will hear a puff of air come out of the spark plug hole, this is the compression stroke. As you keep pushing the kick starter through, the piston is now going down on the power stroke, when the piston reaches the bottom and starts to come back up you will see the exhaust valves open and it will be coming back up on the exhaust stroke.

As the piston comes to the top again, you will see the exhaust valves close and the intakes will begin to open, this is top dead center where you DO NOT WANT TO ADJUST THE VALVES. This is known as overlap Top Dead Center.

As I said before, as you continue to push the kickstater through, the intakes will fully open, and as the piston approaches the bottom of the stroke, the intakes will begin to close, as I stated before the engine will free wheel a bit here. Now, put a LONG plastic ty wrap into the spark plug hole, and, using a 17mm end wrench, not a socket with a ratchet, on the nut that holds the flywheel on, continue to spin the engine in the direction it was going when you were pushing on the kickstarter. Watch the ty wrap as you turn the motor, you will see the piston pushing the ty wrap up out of the hole. Do this very slowly, and you will come to a point where the ty wrap no longer is moving up even though you are still turning the crankshaft, this the TDC or top dead center of the compression stroke, and THIS IS WHERE YOU WANT TO ADJUST THE VALVES.

If fact, if you use the kick starter in little short jerks you can get it on TDC of the compression stroke without taking the ignition cover off, and just use the method above and the long ty wrap.

NOTE: If you try and turn the motor backwards it will be very difficult because you will be engaging the starter sprag of the electric start, and you will be turning the electric start motor too. Just keep going in the direction that the kickstarter spins the motor, and come around again.

If you go past TDC, no problem, just keep turning the motor with your wrench and watch the ty wrap go down on the power stroke, up again on the exhaust stroke, down again on the intake stroke, and as you come up again you'll be on the power stroke. ( Keep a firm grip on the wrench at all times as I mentioned before the motor will want to free wheel a bit after the intake stroke and if you're not paying attention you could get your fingers pinched. It's not going to rip the wrench out of your hands, but, if you're not ready for it, it can surprise you. Voice of experience speaking here.) keep going till you get back close to TDC on the compression stroke, now just take your time and slowly turn the crank with your wrench and wait for the ty wrap to stop moving up. Wa-Lah! you're back at TDC on the compression stroke where you want to adjust the valves.

Look carefully at your flywheel and motor casings, on my 04, there is a red line that was obviously put there by hand at TDC at the factory, a mark on the cases, and another on the flywheel. If it's there, and you followed the above procedure, it will just give you some conformation that you have arrived at the correct spot. If the marks are there but are not lined up, and you would have to move the flywheel a bit to get them lined up, try doing so and keep an eye on the tywrap if you don't see it move any, don't worry, you're there. You could only see movement of the tywrap at this point if you had a dial indicator on it, trust me, you're close enough. If you really want to be sure, do as Dale Lineaweaver suggests, and get the locking bolt as described in the 2005 repair manual and insert it on the compression TDC as directed in the book. But, I don't think the bolt is necessary.

Now that you're there, check the amount of clearance first, you may not need to adjust the valves. When checking the clearance, be sure you push the feeler gauge back and forth parallel with the rocker arm shafts, or parallel with the crank shaft. Be careful with the feeler gauge, do not force it! It will break off and fall down into the rocker box and you will have to retrieve it with a small pencil (uh oh) shaped magnet. This has happened to me in the past, if it happens to you do not panic. And what ever you do, do not start the bike, or poor oil through the valve cover in an attempt to flush it out. You will not get away with this and You will be sad.

Loosen the lock nut of the valve to be adjusted and back it off a turn or so, turn the adjuster ( the screw with a slot in it for a screw driver) counter clockwise to increase the gap, and clock wise to decrease the gap. I usually just open up the gap so I can get my feeler gauge in there easier, and then gently turn the adjust down onto it. There should be noticable drag on the feeler gauge, but, not so tight you can barely move it. With the feeler gauge still in place snug up on the lock nut, and check the feel of the feeler gauge. If it has not changed, tighten the nut to the torque specified in the book, and check it again, if it's changed do it over and set a bit looser intially, if it doesn't change you're done with that one. You do not want to overtighten these nuts, as they will deform the adjuster nut threads, and it will be a ***** from then on when ever you want to adjust the valves. I'm not going to go into that now, just don't over tighten them. Get yourself a small torque wrench and use it, you'll be happier in the long run. (Again this is the voice of experience talking here)

Always allow plenty of time to do this procedure, turn off the phone,radio,tv, etc... don't do it in the company of others, do it all alone in a quiet place without any distractions. Don't rush!!

I hope this helps.
 
Here is what I consider the best tutorial for adjusting the valves written by Daleo. I use the 1/6th turn method instead of using a feeler gauge though:

How about this for starters?

Get an offset feeler gauge made for adjusting valves. They come with two feelers, one on each end, you need the one with a .004" & .005".

Then try this procedure:

Read this all the way through before using this as a guide.

with the vlave covers off, the ignition cover off,the spark plug out, push the motor through several times watching the intake and exhaust valves open and close.

You will notice that when the intake valves open, the piston is going DOWN on the intake stroke. Then, as you keep pushing on the kick starter the motor will kind of fee wheel, the intake valves will snap shut, and you will hear a puff of air come out of the spark plug hole, this is the compression stroke. As you keep pushing the kick starter through, the piston is now going down on the power stroke, when the piston reaches the bottom and starts to come back up you will see the exhaust valves open and it will be coming back up on the exhaust stroke.

As the piston comes to the top again, you will see the exhaust valves close and the intakes will begin to open, this is top dead center where you DO NOT WANT TO ADJUST THE VALVES. This is known as overlap Top Dead Center.

As I said before, as you continue to push the kickstater through, the intakes will fully open, and as the piston approaches the bottom of the stroke, the intakes will begin to close, as I stated before the engine will free wheel a bit here. Now, put a LONG plastic ty wrap into the spark plug hole, and, using a 17mm end wrench, not a socket with a ratchet, on the nut that holds the flywheel on, continue to spin the engine in the direction it was going when you were pushing on the kickstarter. Watch the ty wrap as you turn the motor, you will see the piston pushing the ty wrap up out of the hole. Do this very slowly, and you will come to a point where the ty wrap no longer is moving up even though you are still turning the crankshaft, this the TDC or top dead center of the compression stroke, and THIS IS WHERE YOU WANT TO ADJUST THE VALVES.

If fact, if you use the kick starter in little short jerks you can get it on TDC of the compression stroke without taking the ignition cover off, and just use the method above and the long ty wrap.

NOTE: If you try and turn the motor backwards it will be very difficult because you will be engaging the starter sprag of the electric start, and you will be turning the electric start motor too. Just keep going in the direction that the kickstarter spins the motor, and come around again.

If you go past TDC, no problem, just keep turning the motor with your wrench and watch the ty wrap go down on the power stroke, up again on the exhaust stroke, down again on the intake stroke, and as you come up again you'll be on the power stroke. ( Keep a firm grip on the wrench at all times as I mentioned before the motor will want to free wheel a bit after the intake stroke and if you're not paying attention you could get your fingers pinched. It's not going to rip the wrench out of your hands, but, if you're not ready for it, it can surprise you. Voice of experience speaking here.) keep going till you get back close to TDC on the compression stroke, now just take your time and slowly turn the crank with your wrench and wait for the ty wrap to stop moving up. Wa-Lah! you're back at TDC on the compression stroke where you want to adjust the valves.

Look carefully at your flywheel and motor casings, on my 04, there is a red line that was obviously put there by hand at TDC at the factory, a mark on the cases, and another on the flywheel. If it's there, and you followed the above procedure, it will just give you some conformation that you have arrived at the correct spot. If the marks are there but are not lined up, and you would have to move the flywheel a bit to get them lined up, try doing so and keep an eye on the tywrap if you don't see it move any, don't worry, you're there. You could only see movement of the tywrap at this point if you had a dial indicator on it, trust me, you're close enough. If you really want to be sure, do as Dale Lineaweaver suggests, and get the locking bolt as described in the 2005 repair manual and insert it on the compression TDC as directed in the book. But, I don't think the bolt is necessary.

Now that you're there, check the amount of clearance first, you may not need to adjust the valves. When checking the clearance, be sure you push the feeler gauge back and forth parallel with the rocker arm shafts, or parallel with the crank shaft. Be careful with the feeler gauge, do not force it! It will break off and fall down into the rocker box and you will have to retrieve it with a small pencil (uh oh) shaped magnet. This has happened to me in the past, if it happens to you do not panic. And what ever you do, do not start the bike, or poor oil through the valve cover in an attempt to flush it out. You will not get away with this and You will be sad.

Loosen the lock nut of the valve to be adjusted and back it off a turn or so, turn the adjuster ( the screw with a slot in it for a screw driver) counter clockwise to increase the gap, and clock wise to decrease the gap. I usually just open up the gap so I can get my feeler gauge in there easier, and then gently turn the adjust down onto it. There should be noticable drag on the feeler gauge, but, not so tight you can barely move it. With the feeler gauge still in place snug up on the lock nut, and check the feel of the feeler gauge. If it has not changed, tighten the nut to the torque specified in the book, and check it again, if it's changed do it over and set a bit looser intially, if it doesn't change you're done with that one. You do not want to overtighten these nuts, as they will deform the adjuster nut threads, and it will be a ***** from then on when ever you want to adjust the valves. I'm not going to go into that now, just don't over tighten them. Get yourself a small torque wrench and use it, you'll be happier in the long run. (Again this is the voice of experience talking here)

Always allow plenty of time to do this procedure, turn off the phone,radio,tv, etc... don't do it in the company of others, do it all alone in a quiet place without any distractions. Don't rush!!

I hope this helps.
Thank you very much for the reply! This helps a lot, I believe I am at the compression stroke TDC. There’s no pressure on any of the rocker arms (i can jungle them by hand). But just so happens the previous owner stripped one of the valve adjustment bolts so have to take the whole head apart to replace that anyway :( so while I’m in there I’ll be sure to double check the cam lobes and make sure they are pointed at 8 and 4 o’clock as I’m told that’s where they should be at tdc compression stroke. Thanks again!
 
there is a mark on the flywheel. it is a tiny triangle and there's a mark on the cracnkcase at the ignition cover join. it is around at about 10.30 on the face. it's a very small mark.

Taffy
 

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