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Discussion Starter #41
How did you guys determine the correct timing chain tension? The service manual only states: "Unlock the timing chain tensioner screw counterclockwise" (how far??) and "Check the timing chain tension" (to what specs??)
It's an automatic chain tensioner. When you remove it, you just "disengage" the tension on the chain. Very simple, no problems here.
 

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I've already done the Spal Fan/engine ice. If I only need to check valves and possibly replace some shims, will removing radiator mount fasteners (leaving all hoses attached) allow the radiator to swing out of the way far enough to be of value, or is complete removal necessary?
 

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Discussion Starter #43
Hmmm... Good question... I think it's worth it to go at it by increments.

Try not touching the rad, then just loosening the mounts, then unplug the hoses if all else fails...
 

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Luc - how many hours (cost) would you estimate a capable tech at a KTM garage would should take to complete the valve adjustment -

My bike is at the shop now and ready to pick it up in a few hours - just wondering what to expect -

I do know from experience first hand that taking things apart on the 390 is a chore as I installed the Bazzaz F-1 last week - took a long time to disassemble
everything

thanks

Steve


Hello again everyone!!

I AM DONE!!!! Job completed!

Just check out the link again.

Spoiler alert : I now have a charming valve clicking sound, but I love the SPAL fan! :)
 

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It's an automatic chain tensioner. When you remove it, you just "disengage" the tension on the chain. Very simple, no problems here.
Ok, got it thanks. That's how the tensioners on my other bikes work.
I checked my valve's clearances this morning and they were extremely tight. EX at 0.13mm (L) and 0.11mm (R) and IN at 0.07mm (L) and 0.06mm (R)! I had to double check my feeler gauges with a micrometer to believe it. I can't believe that some KTM service folks would skip the valve check when performing a service. Glad I am doing all work myself.
 

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http://www.ktmduke390forum.com/forum/engine-technical-discussion/23490-my-valve-clear

I read- somewhere on HERE- that KTM service people are allowed 6 hours to do a valve clearance adjustment on these motors. Considering that your motor might be the very first one that these people have ever encountered- it could take more hours than that to do this, (at-let's say 100 bucks per hour?)- so they don't even try it.........
Only one way to know for sure: DO IT YOURSELF! (All of the info to do that, is right HERE- look it up!) Save yourself 600 bucks+ in service charges in the process!
things like this are what this forum is all about- take advantage of it.
 

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Discussion Starter #47
Steve[/QUOTE]

Ok, got it thanks. That's how the tensioners on my other bikes work.
I checked my valve's clearances this morning and they were extremely tight. EX at 0.13mm (L) and 0.11mm (R) and IN at 0.07mm (L) and 0.06mm (R)! I had to double check my feeler gauges with a micrometer to believe it. I can't believe that some KTM service folks would skip the valve check when performing a service. Glad I am doing all work myself.
I would try to keep it on the tight side of acceptable. It put mine right in the middle of the tolerance, and got valve lifter clicking when I was done...
 

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Discussion Starter #48
Luc - how many hours (cost) would you estimate a capable tech at a KTM garage would should take to complete the valve adjustment -

My bike is at the shop now and ready to pick it up in a few hours - just wondering what to expect -

I do know from experience first hand that taking things apart on the 390 is a chore as I installed the Bazzaz F-1 last week - took a long time to disassemble
everything

thanks

Steve
I would say between 4-6 hours... But if they'Ve never done it before.... You can't really say. I would probably ask for a formal quote... But surely it is feasible at home, just take your time
 

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Update on my encounter at my local dealer ( Dave Russell KTM )
He did my valve check and did find the valves needing adjustment and shims. Total charge $200.00 ( two hours ) which I thought was a bargain - he also did the fan and flushed the radiator and replaced it with engine ice at no charge as he said the bikes are running too hot - the change will bring the temp down by 20 degrees.

I am a very pleased owner - this bike is a joy to own and ride in town and in the nearby twisties -
 

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Luc, is the 1/2" drive castle nut wrench needed to turn the crankshaft to TDC, or can another tool be used to turn the motor over once the spark plug is out?

Also, does oil need to be drained before the valve work, or is the oil level well below the crankshaft case plug? (I'm not down at the bike right now, and can't remember the relation of the sight glass to the access plug)

I thin I'm gonna tackle this next week. (I just hate the idea of not being able to ride it for a couple days!!)
 

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Discussion Starter #51
Luc, is the 1/2" drive castle nut wrench needed to turn the crankshaft to TDC, or can another tool be used to turn the motor over once the spark plug is out?

Also, does oil need to be drained before the valve work, or is the oil level well below the crankshaft case plug? (I'm not down at the bike right now, and can't remember the relation of the sight glass to the access plug)

I thin I'm gonna tackle this next week. (I just hate the idea of not being able to ride it for a couple days!!)
I just used a regular socket on the nut to turn the crankshaft (and yes, remove the spark plug)

No need to drain the oil, you'll be fine

You can do it!! go slowly if you want to finish fast ;-)
 

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I've already done the Spal Fan/engine ice. If I only need to check valves and possibly replace some shims, will removing radiator mount fasteners (leaving all hoses attached) allow the radiator to swing out of the way far enough to be of value, or is complete removal necessary?
So, this for those of you NOT wanting to drain the cooling system and remove radiator entirely to check valve clearances:

Answering my own question re: radiator loosen vs remove.

Exhaust valves are checkable without totally draining and removing radiator. If radiator mounting nuts/washers are removed, the radiator can swing forward an inch or two, increasing available space and allowing reasonable access to get a feeler gauge in there.

Gotta say, after doing mostly Moto Guzzi's with the jugs hanging out in the breeze, and having never worked with shims, this job is a real PITA!

A zillion thanks to Luc for his great tutorial!!

Another recommendation after doing the job that helps with reassembly. It seems, for me at least, that it's nearly impossible to remove/replace cams without the cam chain jumping teeth on the lower sprocket. I degreased two spots on the chain with lacquer thinner and marked the exact chain pivot at the "T" marks on each sprocket so I could get them re-oriented with the correct number of links between. If counting each link as two pivot points and counting the first "T" as #1 , the second "T" engages the chain at #1 3 pivot. It's not that easy to see if you're out of time by a half link (one pivot), so this might help someone tackling the job.

Also, taking pictures for reference during breakdown is a huge help.
 

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Finished!!! (Yikes, what a job!)

I've done lots of valve clearance adjustments in the past, but all were the screw-adjustable tappets, allowing exact adjustment to a thousandth of an inch. Also, most were on Moto Guzzis, which have the heads right out in the breeze, so difficult access is really never an issue. Other than the nuisance of difficult access in the 390 Duke, which everyone comments on, the shims were a new experience for me. For those with similar experience, I offer these observations.

First, at least with the Hot Cams set, shim sizes vary by .05mm, which translates to just shy of .002" (.00192" IIRC) The target gap for the intake valves is between .0031"-.0047" (.08mm -.12mm) So your smallest increment of adjustment is about 110% of the acceptable range! This makes it nearly impossible to hit a target gap dead on the money unless you custom-grind the shims yourself, which would require a fairly sophisticated setup to do accurately. So, rather than setting clearances at the wide end of the specified range as I normally would, (allowing for things to tighten with time and use) I pretty much found only one shim that lands within the target. The exhaust clearance range is about the same, (.005"-.0067" or .13mm-.17mm) Measure the HotCams shims with a dial caliper or micrometer, as I found that some were as much as .002-003mm oversize. (None that I measured were undersize) The actual use of the feeler gauges, most of which have .001" (.025mm) increments in these ranges, pretty much leaves a go/no-go use, as in, "Well, it's looser than .003" but too tight for .004", so call it .0035". Makes my natural bent toward precision squirm a bit. :eek:

For me, I ended up with about .09mm on intakes (one shim size .05mm either more OR less put it outside specs) and about .16mm and .17mm on exhausts, towards or at the larger end of the recommended gap.

Measurements done on the go/no-go basis, but definitely within KTM's spec range.

Job took several hours over a 2 day period, mainly because I changed shim sizes and reassembled the cam box/chains/ tensioner assembly 4 times trying to hit my predetermined target on the nose before I finally realized that my smallest increment of adjustment was wider than the entire KTM-specified range. So, in summary, my advice would be that if you get a shim size that puts it anywhere within the adjustment range, you've probably gotten as good as you're going to get, and button it back up and go riding!!

Based on the potential level of "fitting and trying" involved, I WOULD recommend getting the HotCams kit, rather than trying to order the precise shim size needed. You might save a few bucks ordering individual shims from the dealer , but one or two miscalculations, especially with the challenge of making precise measurements with the feeler gauges, would generate LOTS of extra aggravation waiting for reordered parts (especially if some of the shim sizes are back-ordered)!:crying:
Oh, one more thing. If you're shooting for INCREASED valve clearance, you need to DECREASE the shim size. Not that I'd know that from experience or anything...:rolleyes:
 

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Time for a second (or third) beer, John! Nice job and helpful observations!
 
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BTW, I verified that the KTM factory shims come in the same .05mm size increments as the HotCams. Can't verify the precision of the KTMs vs the others. Some (not all) of the HotCams sizes were measuring out .001mm-.003mm greater than the indicated size with a Mitutoyo dial caliper.

My point being that the incremental nature of shim replacement would be no better with the factory shims, and with the added cost as well as the inconvenience of having to special order them individually, with concurrent back-order possibilities.

All part of the fun! (?)
 

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John do you have a good micrometer to measure the difference in shims.
 

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John do you have a good micrometer to measure the difference in shims.
I do have a couple good Starrett mics, but not a metric. I do get pretty repeatable results with the Mitutoyo metric dial caliper, and repeated each measurement 2-3 times. Of course I have to interpolate the last digit, but I'd say that puts the reading to a reliable + or - .001 mm
 

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Further tip: Avoid over- tightening the adjuster screw cover cap on the cam chain adjuster. The castle nut inside the adjuster which receives the cap bolt is made of a brittle alloy and is prone to stripping. Apply just enough pressure on that 10mm nut to compress the O-ring. Mine was already failing when I first checked it, possibly due to exuberant wrenching by assembler or PO(?) Then after doing the valve check five times (!), pieces of thread were coming out.

Good news? Replacement cam chain adjuster is only 16 bucks. PN 90136003003 (plus an 85 cent each gasket and O-ring, just to be sure!)
 
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