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Discussion Starter #3
Makes sense - especially if only 1 is outside range for instance. They're readily available as a rule?
 

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Makes sense - especially if only 1 is outside range for instance. They're readily available as a rule?
not sure bud, first time I have actually had to change them, however when a garage takes in bikes as trade-ins they will need to service them so would imagine that they will possibly have shim sizes for all different sorts of manufacturers and models.

Time will tell. I still have to get old ones out and see what size they are so I know what new ones to get. only measured them yesterday.

let me know how you get on :)

p.s surely ktm will stock them however, I would imagine like everything else, they will come at an excessive price
 

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Discussion Starter #5
Got into it today and checked the clearances. All within spec, but one inlet is 0.08mm and one exhaust 0.13, so right on the bottom limit. The others are smack in the middle of their range.
As I've gone this far, it makes sense to adjust those that are getting tight, but as I'm going to have to lift the cams and get a pair of fresh shims anyway, does a sensible person take them all back to max permissible clearance while they're about it?
 

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Got into it today and checked the clearances. All within spec, but one inlet is 0.08mm and one exhaust 0.13, so right on the bottom limit. The others are smack in the middle of their range.
As I've gone this far, it makes sense to adjust those that are getting tight, but as I'm going to have to lift the cams and get a pair of fresh shims anyway, does a sensible person take them all back to max permissible clearance while they're about it?

I just rebuilt the bike from doing mine. I got shims from KTM. My clearances were all tight upon checking them, I had both inlets 0.07mm and exhaust at 0.10mm. I have now got inlet at 0.12mm and exhaust 0.15mm so still tight but within tolerance. I think I will just check again in another 1k miles or so as I think the new shims might wear a fraction with being new.

Didn't want to risk going too small with the shims to raise the clearance in case went to big.
 

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Here's my grrrr question on the subject... and tryta forgive me for being a **** mechanic, but i also haven't been into this top end yet, so here goes.


The cam followers are only held in place by two #90236056000 Valve Lever Shafts; which, coincidentally, are only held in place by two #90136056001 Screw Plugs that remove from the left side of cylinder head. See the attached pics.


But before I go too far with this, I'm gonna plant something right out front. The 2016 and 2017 rep manuals call out .08 - .12mm on the intake and .13 - .17mm on the exhaust; whereas, the 2018 rep manual calls out .10 - .15mm on the intake and .15 - .20mm on the exhaust. Hmmm... it'd been 8-12 and 13-17 all the way from 2013, according to documentation... then they finally widened it on the 18 and 19 models... Ok, enuffa that.


Back to the point -- I know the docs say the followers are DLC coated, but I'm only assuming they are 'steel', are they aluminum? Can anyone confirm this?


If they are steel, and if they have not worn into those shafts that support them, they could be easily suspended by multiple magnets, while one 'valve lever shaft' is removed at a time, and the shims extracted/replaced. I'm sure you can see what I might be getting at, the cams/chains etc would not even need to be removed to do the deed.


Maybe you have doubts about that being possible, but think about it... If there is 4-6-8 thousandth inches clearance between the rocker and cam with the engine at tdc, the shaft slides out (via magnetic extraction, or is its end threaded?), the rocker is rocked outta the way, the shim is picked out via another magnet and measured, a different shim is installed and [wow go back together].


Also, the Hot Cams 31 shim kit is the one that services this engine. They're 1.85 - 3.2 mm thick shims, 10mm in diameter in that kit, just like the factory parts... and they also graduate in .05 mm, so there really isn't a lot of fine differentiating going on there. What I mean is you need to think "is +/- .05 gonna take me outta spec?" Or maybe a better question might be, do you have a set of diamond lapping files, to do a little customizing on the shims bottom side.


The final thing I noticed was the dif between the 2018 and 2019 duke owners manuals. 2018 was when they changed to a looser valve clearance spec; the very next year, 2019, they apparently did away with the 1000km valve clearance check.


The pictures are captioned, in case they don't make sense at first.
 

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But before I go too far with this, I'm gonna plant something right out front. The 2016 and 2017 rep manuals call out .08 - .12mm on the intake and .13 - .17mm on the exhaust; whereas, the 2018 rep manual calls out .10 - .15mm on the intake and .15 - .20mm on the exhaust. Hmmm... it'd been 8-12 and 13-17 all the way from 2013, according to documentation... then they finally widened it on the 18 and 19 models... Ok, enuffa that.
For your information. It has a official position of KTM R&D.
https://www.ktmduke390forum.com/forum/engine-technical-discussion/44087-2018-service-manual-diff-valve-clearance.html

Luis
 

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LNICK... big shout out to Rio, what a gorgeous place to live and ride!



and yeah, I just read that post you mentioned; good to see there are other mechanics on here (from ALL parts of the world), and that someone previously noticed and pointed out the change. I especially liked the quote about...


"After speaking to our R&D department I can give you the following feedback:
During the product development process, the valve clearance values have changed from MY17 to MY18.
The new values (intake: 0,10-0,15mm; exhaust: 0,15-0,20mm) can also be used retrospective for the old models."



I'm assuming that's what you were referring to when you said "It has a official position of KTM R&D". And kudos to KTMasean for getting the low-down on all that; otherwise, who'd know? Did the Admin ever make that a sticky at the head of the forum?
 

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Graham, I just watched your video and I gotta tell ya, I'm definitely getting pains across the water. :eek:


[hold on, lemme get my tools! i gotta turn the burner off quick, but I've been dying for a chance to get the yell away from the fools I work with... and, well -- you're in Europe, right? that works for me, I'm in the US, but I'll paddle if I have to]:D


Ok, enuffa that, sorry. But I think I've got an idea that might just pay off for you... and it goes hand in hand with one of my favorite principles, K.I.S.S. Or at least that's what I tryta tell myself a lot of the time. So here goes...


If you've got a buddy with a leak-down tester, set that motor up on TDC with all the valves closed, then start pressurizing the cylinder slowly to around 40 psi. You don't want the motor to rotate, that's why it's got to be right on tdc (and why only about 40 psi).


Listen at the exhaust, also roll the throttle open with the air filter removed, and listen for any air passage out of the engine valves through those systems. If it's coming out of the intake side, make sure it's not a ring/crankcase leak passing air back to the air box through a hose.



Why would I recommend this? Because it is the 'least invasive' test you can make, and it's one that will help establish whether you're actually 'holding onto' whatever compression the engine can make. To me, it acts like it is very weak at those low rpms of cranking. Did you also say somewhere else this engine stalled a lot at stops on you? See where I might be going?
 

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Thanks for that I will give that a go. I've also been thinking it could be low fuel pressure too as it will start up OK once its been running once. I've just ordered a kit to see if its making good fuel pressure
 

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Have you adjusted the valves yet?
 

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Discussion Starter #15
Naaaa..... I'm not in a rush!
Currently trying to borrow a micrometer - I just for fun, I want to check my clearance values against the actual thickness of the current shims. It might lead to greater clarity or deeper confusion.... we shall see!
I also got another feeler gauge - a Facom 804 - which has more and finer blades than the one I used initially. One exhaust is tighter than previously measured (0.10 not 0.13) and one inlet too though only by 0.01.
I'll keep you posted as I'm sure you're all lying awake at night wondering how I'm processing!
 

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Hi T-Mack,

You'll need to measure the current shims in order to know what size new shims to install. A nice digital caliper is not too expensive and a good tool to have around.

Cheers!
Craig
 

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Discussion Starter #18
Ok. Measured all shims with the micrometer.
These values, plus measured clearance, minus desired clearance, equals new shim thickness if I understand correctly.
Which is fine except that one inlet (measured clearance 0.08, right on the limit) would need a 2.42 shim to get to 0.12 (max clearance). As the shims only come in 0.05 increments I'll go over the upper limit for clearance.
My question is should I go over by 0.02 and let it wear in over the next 4000 miles? Or stay with what I've got and check it again in say 1000 miles?
I'd rather not have to check it again so soon as I'm sure you can understand!
 

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My question is should I go over by 0.02 and let it wear in over the next 4000 miles? Or stay with what I've got and check it again in say 1000 miles?
I'd rather not have to check it again so soon as I'm sure you can understand!
Believe or not the clearance will become tighter with time. There is a wear but it's easily compensate by metal expansion.
I use to do it at least each each 15K km.
Luis
 

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I would go with the larger gap. As Luis said, The gaps tend to tighten with miles. Either way will be okay since Intake valves do not burn as easily as exhaust valves with the same (small/tight) clearance.

If you are picking up new shims from a supplier in person, measure every single one of them as you may find the variation that you need
 
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