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Re: 2009 KTM 250 XC-F engine project

Posted: Wed May 19, 2021 4:30 pm
by RevMatch
Late to the party, but Have you tried a compression test? They can be a bit tricky as the cam has a built in De-Comp lever that’s easily defeated with a zip tie.

I can’t picture the timing chain in my head but (big butt) I think the tensioner can throw off your tooth math.

Re: 2009 KTM 250 XC-F engine project

Posted: Wed May 19, 2021 11:20 pm
by smdub
I have not done a compression test (due to aforementioned auto-decomp. Never thought about defeating it w/ a ziptie though.) It feels like really good compression though. It's about as hard to kick start as my trials bike. W/ a 'new' head and new piston & rings it better have good compression! :)

Tensioner is always on the slack side of the chain. It doesn't affect cam timing.

Flywheel puller should be here tomorrow. :pray: I have a million other things I need to be doing instead but I probably won't be able to resist using it to confirm/deny when I get home.

Re: 2009 KTM 250 XC-F engine project

Posted: Wed May 19, 2021 11:26 pm
by smdub
@RevMatch - Joe? (I'm guessing from your location and join date it's you.) Good to see you found us. :cheers:

Re: 2009 KTM 250 XC-F engine project

Posted: Thu May 20, 2021 9:48 pm
by smdub
Redemption MF! :loveit:

Re: 2009 KTM 250 XC-F engine project

Posted: Fri May 21, 2021 8:19 am
by RevMatch
You figure me out already 😬

Your suspicions we’re right! Point the kids to this thread when they start doubting you.

Re: 2009 KTM 250 XC-F engine project

Posted: Sun May 23, 2021 4:36 pm
by smdub
New flywheel key.

Re: 2009 KTM 250 XC-F engine project

Posted: Mon May 24, 2021 7:48 am
by Laoch
Sounds good. Congrats on figuring it out :thumbup:

Re: 2009 KTM 250 XC-F engine project

Posted: Mon May 24, 2021 8:11 pm
by smdub
The all important picture of where the flywheel magnet should be at TDC. If I could have found this information before I would have known the key was sheared.
I suspect this is correct for the 2009 250 XCF, XCF-W and SXF as I think they all share the same crank.

Re: 2009 KTM 250 XC-F engine project

Posted: Mon May 24, 2021 9:22 pm
by Bucho
Nice! Satisfying to figure it out.

Re: 2009 KTM 250 XC-F engine project

Posted: Sun May 30, 2021 8:52 pm
by smdub
The muffler inlet ID is about 1mm larger then the header OD. It doesn't seal and you can feel the exhaust gasses escaping. None of the parts diagrams show any sort of gasket but there has to be something. My new Husky 701 uses a graphite ring in a setup that is almost exactly the same. So I used some graphite tape and made my own. Its a good tight fit and actually quieted down the bike a bit (it was really obnoxious before - now its just loud.)
20210529_graphite_header_gasket_r800.jpg