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valve adjustment

Joined Apr 2005
55 Posts | 0+
Mobile Alabama
'04 450FE - Yes I've read the doc.
I had a friend come over to help adjust the valves because I wasn't sure if I was on TDC on the comp stroke. He proceeded to show me how to turn the engine over with the rear wheel until the exhaust valves start to open, and then he adjusted the intake. He then rolled the engine over till the intakes closed, then just back to where they were almost closed, at which point he adjusted the exhaust valves. The scarry part to me was it took a couple of full revolutions out (ccw) before the feeler gauge would fit. He didn't seemed concerned (of course it wasn't his bike). All 4 valves required about the same adjustment.
After putting it all back together, the bike has waaay more compression. It started on the second kick. The valve train noise seemed louder than normal, but I may be listening too hard. I shut it off after a few seconds and tried starting it with the button, but the starter would not even turn the bike over. I had no problems with the starter before. He said I had a weak battery. My question is, does this sound reasonable? Could the valves have been so far out that I had little compression, and the starter was able to turn the bike over? Now with proper compression, the weak battery becomes obvious. Or are the valves now so mis aligned it's hard to kick and no battery would turn it over?

Dalton
 
Im not sure if your bud got it right. Did he do the 1/6/ /1/8 turn method?
If he got too much clearance then the auto decomp is not working. If the bump on the cam cant lift the exuahst valve then you will have too much compression for even a fresh fully charged battery.
The old expression ... " a noisy valve is a happy valve" is true to a point but they really need to be in tolerance.
Do a search on valve adjustment..... we have been down this road more than once.
If you get the tdc on the compression stroke you will NOT need to move the motor to do the adjustment on both sets of valves. It is also hard to get a standard feeler guage in hence the 1/6th turn method.

Someone else want to confuse this poor guy more than me????????????? :lol:
 
Thanks Bob

Im not sure if your bud got it right. Did he do the 1/6/ /1/8 turn method?

He used a gauge, and I verified with the 1/6th turn and the gauge, and they all seem ok.

Do a search on valve adjustment..... we have been down this road more than once.

And I've read all that I could find. And they usually say something like "Loosen the nut, turn the screw in till you feel resistance, then back out 1/6th turn". What I am seeing is after loosening the locknut, I had to turn out (ccw) 1.5 to 2 turns to get off the spring. Then I was able to set the gap using the 1/6th turn method or the feeler gauge method. Is that unusual? or is his method not putting me where I need to be to check the clearance?

Thanks again,
Dalton
 
wuw! sir!

that is wrong! you don't need to unscrew the centre screw two turns to set the tappets.

i would say that you weren't at TDC and that your freind got it wrong. your auto decomp now doesn't work and yes: your comp is too high.

do this another way please. take off the flywheel cover, stick a T-bar on there. remove the spark plug nd the rocker inspection covers. turn the engine over clockwise with the T-bar. watch the inlets go down (open) and then up (and close). now stick a screwdriver or rod in the plug hole and you should be about 1" short of TDC.

keep turning clockwise and when the rod is as high as it can go - you are at TDC.

only use the 1/6th method next time because it's easy and therefore a more "sustainable" method that you'll be doing happily in 5 years timew.

regards

Taffy
 
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Taffy got you on the right track. You dont have to use a screw driver to find tdc. I prefer a long ziptie. Cant scratch the cyl. What ever you do DONT use a pencil :p
I think Taf hit the nail on the head when he said you were NOT in the proper timming. You should only need to loosen the screw at most 1 turn if that. The real trick is holding the screw part of the tappet while getting the nut torqued. Motion pro makes a trick set of valve tools or you can make your own. After you do this twice you will be down to 20 minutes tops :D
Let us know how it goes.
 
[

And I've read all that I could find. And they usually say something like "Loosen the nut, turn the screw in till you feel resistance, then back out 1/6th turn". What I am seeing is after loosening the locknut, I had to turn out (ccw) 1.5 to 2 turns to get off the spring. Then I was able to set the gap using the 1/6th turn method or the feeler gauge method. Is that unusual? or is his method not putting me where I need to be to check the clearance?

Thanks again,
Dalton[/quote]

If i'm reading this correctly - you are saying that you needed to back the tappet adj screw off for 1.5 to 2 turns before you could get any clearance at all? If this is the case and you, yourself, have the valvetrain in the correct position whil you are doing this (have you done a check?) then your mate will have done the tappets up so much that the valves will not be closing properly and there should be no compression - ie the opposite of the symptoms you describe. I think you should start again from 1st priciples checking and reching as you go to make sure TDC is where you think it is etc etc.
 
Well, I started over and re adjusted the valves from TDC on the comrpression stroke and the exhaust valves were way off. The intake was ok. After fixing the exhaust side the bike runs fine and turns over with the button.

It's easy if you know how to do it. :D


Thanks for the help,
Dalton
 
Thats what this site is for
Glad it worked out
Now go teach your KTM buddy how to do it right! :twisted:
 
Thanks Taffy! :)

I just did my first on the 'berg - I've done it before on the old KTM 450 EXC -03, and I did that one the ktm way, inlet adjusted when the exhaust are opening, and the exhaust when the inlet is about to close - as per this video http://www.youtube.com/watch?v=hWS9RuEQzc8.

A bit fiddly...I prefer your way, adjust all tappets at once after finding the correct tdc, inlets open and then closed, then go on until piston is at tdc.

My engine has done a bit over the recommended 3 hours since new (say 5... :D ) - and I tried to use a feeler gauge, but I could never get a reliable reading from those on the rfs - same story here, it's almost as if the tappets are slightly cupped, because where they were from factory felt ok on the inlets (0.12 mm), but the exhausts were slighly tight, I could only get the 0.10 mm feeler in there.

But, using the 1/6 method, I got the tapped adjuster down a bit more than 1/6 on the exhausts, and even a bit more on the inlets (using the hi-tech method of aligning nut edges with the groove :D ).

Do they come with excessive clearance from factory...? Running the engine it sounded a bit more smooth, and the decomp still worked as it should, so I assume all is well. :)

/J
 
where would we be if the factory hadn't used such viscious cam profiles that forced the factory to keep the followers very close. i think we'd be using feeler gauges and have different gaps for inlet and exhaust.

what are the gaps on a ktm?

regards

Taffy
 
Hi Tafffy!

The RFS engine is exactly the same, 0.12 mm in both inlets and exhaust valves.

I think it's a bit of a problem, as you can't really use feelers to see how much it has moved from time to time...if the 1/6 (done very carefully, holding back the screw ever so slightly when tightening the nut) results in not being able to get a 0.12 mm feeler in there.

Using a feeler gauge to set the screw with resulted in more play (could be felt by just rocking the tappet up and down with your fingers)...so something is amiss here - does anyone know if the tappets are slightly cupped even when brand new? :)

/J
 
I bought a Porsche 911 valve adjustment tool. Quite expensive, but i felt i needed this "bling" thing. It works excellent on the Bergs but the 1/8 method works fine also.
The disadvantage with the feeler gauge is that the surfaces on the tappet and the rocker might not be entirely flat after wear which gives little bigger clearance in reality.

Christer /450E -07
 
That's the thing Christer (tjena, Jerry här - relativ färsking från Västeråskrokarna, hämtade en 08 FE450 i Örebro hos Laxå Marin för ett par veckor sedan, vilken hoj...det är det här man skulle haft istället för 300:an i sextimmarsspåret...) Sorry about the swedish lads :D...

My engine is brand new, and the tappets haven't had time to develop a slight cupping - but still I feel as if there is some - as adjusting with a feeler gauge ended up with noticeably more play than the 1/6 method (which I've used several times on my old exc450 rfs engine).

Another question - I didn't have the decomp wire left in place on my old KTM, my new 'berg has it - I assume you don't need to remove that to adjust the exhaust valves, as it doesn't make contact at all unless I pull the small lever about half way of the possible travel (the arm outside of the head does not sit at the stop pin though)?

Rgds

/J
 

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