Topend ****ed ! - Flaking tappet bucket design flaw

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limeyduffa
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Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Thu Dec 24, 2020 12:10 pm

Hello All and Merry Xmas :D

Bad news: I inspected the top end on the rear cylinder of my SMT today. The regressive tappet bucket design fault is present - flaking intake tappet buckets.
1.jpg
The marks on the intake tappet bucket (see below) are like sand paper when I run my finger nail over it. This is an intake tappet bucket I replaced 2 years ago (16000km ago). The bike has done 55000km.
2.jpg
This was the original tappet bucket at the same spot in June 2018 when the bike had 39000km on the clock:
3.jpg
See my post 2 years ago about this when I replaced my base gaskets:

http://www.ktmsmt.com/viewtopic.php?f=13&t=11853

I am not going to keep on replacing tappet buckets (and eventually the intake cam shaft). This is a flawed design. I feel shouldn't have to touch something like this until at least 150000km. Not discovering obliterated buckets at 39000km !. So, I'm just going to put the bike back together and fang the crap out of it until the motor blows up or performance becomes unsatisfactory. I'll then take it to the wreckers and eBay the accessories.

Let me know if anyone wants to buy parts. Happy to ship International: Palmer screen, OEM screen, panniers, OEM cans, seals, gaskets, fork servicing kits, brake pads, spare filters etc. I'll post a list later on.

J
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

fulaSMT
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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by fulaSMT » Thu Dec 24, 2020 2:45 pm

Hi sorry to see that same happens again? Odd for sure, i personally have had this on other brands in past the hard case hardening failed and once it started to peel it hammered cam lobe out in no time! i was running Yoshimura stg2 cams at the time and it cost me dear in long run new/cams rockers etc.
It looks like possibly cam is to blame somehow have you measured lobe centres and seen if this has reduced at all in in dimensions.
at least you have caught it in good time before the impending chewing up ,last thing you need is metal in oil system . $$$$

happy holidays.

;)

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limeyduffa
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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Sun Dec 27, 2020 3:00 am

Hi Mate. Nargh, I can't be phcked. I've spent too much $$$$ on this bike. The bike is back together now. I'll just flog the crap out of it until it becomes unrideable, then sell it to the wreckers. I'm bike shopping now. I'll stick with Jap bikes in future.

J
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Thu Dec 31, 2020 7:20 am

Ok, I've calmed down and had a think about it. Buying a new intake cam shaft and 2 buckets isn't that expensive. So, I've pulled the tank, radiator, airbox/throttle body off again today. Tomorrow I'll do a thorough topend inspection: timing chain tensions, value clearances and your suggested cam measurements to ascertain an all up cost.

I return to my original theory that my bike was used as a parts bin when it was sitting in the dealer for 6 weeks in 2015 (I suspect this, because the cam bridge bolts were rounded on the rear cylinder due to somebody using a cheap hex bit, or their oversized tools would not allow them to turn the bolts squarely). If a thief swapped my buckets, it would be logical for them to also swap the cam shaft - both components would be damaged in the original bike. Nb/ When I replaced my base gaskets in 2018, the intake cam shaft had visible wear.

Thanks for your tip FulaSMT, and happy new year :D
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

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limeyduffa
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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Tue Jan 05, 2021 9:27 am

I pulled the bike apart again for a through look. I estimate I could need about $3kAUD of parts. Therefore, not economical to repair. So back to my original decision - I'll put bike back together and flog it until it becomes unridable.

- 6 buckets need replacing (the bucket on the front right hand intake was very bad. This was in good condition 16000km ago).
- 3 cam shifts have pitting, so need replacing
- I performed your measurements you suggested fulaSMT. I could not find any difference across the lobes of the cams (measured with verniers).
- The timing chain tensions are on the border line range limit. So looks like I could need new timing chain kits as well.
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by motoyoyo » Mon Jan 11, 2021 6:17 pm

That's a bummer. How many km's on the bike?
2013 990SMT, 2008 990SDR, 1999 BMW R1100S

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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Sun Jan 17, 2021 12:23 pm

motoyoyo wrote:
Mon Jan 11, 2021 6:17 pm
That's a bummer. How many km's on the bike?
55000km
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by motoyoyo » Thu Jan 21, 2021 7:06 pm

That sucks. I was hoping to get twice that mileage, at least. Just getting the bike dialed in at 20,000km. Thanks for the heads up. Will be looking out for this at the next valve check.
2013 990SMT, 2008 990SDR, 1999 BMW R1100S

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limeyduffa
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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Fri Jan 22, 2021 10:38 am

Let us know how it goes.
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by limeyduffa » Sat Jan 23, 2021 12:22 am

I am selling my parts and accessories on netrider at half price or less (and some of the items on eBay):

netrider.net.au/threads/ktm-parts-forsale-mostly-990-950-but-other-models-too.277899/

I have some freebees in the list as well.
One shagged 2012 KTM 990 SMT. Will be wrecked. PM me if you need parts + spare parts.

fulaSMT
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Re: Topend ****ed ! - Flaking tappet bucket design flaw

Post by fulaSMT » Mon Feb 01, 2021 3:43 pm

Sadly there seems to be quite some past wear like this on several of the bigger ktm engines, no hard fast evidence to back up failing coating for sure it is scary to see but at least it was found in good time!! no one wants either tight or sloppy clearances. Some folks report going over service times with oils and say odd oil quality to blame? Not convinced. Also there also looks like a super ceeded part number on the shim buckets which as an oem fabricated part would point to design flaw issues on material spec/treatment.( happens alot) .
preventive maintenance is key with any bike for sure. :roll:
I will be having a look at my own at some point over uk winter. ;)

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