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Blown inner clutch cover gasket

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I can't get my inner clutch gasket to stop leaking oil. My bike is a 2009 250 sx with low hours and new to me. When I got it home I rode it down the street and noticed some oil around the gasket so I figured I would replace it before going on a weekend trip. I cleaned both surfaces really well, used a new gasket, and dabbed both surfaces with yamabond. I got the cover bolts finger tight and let it dry over night before torquing the cover bolts down the next day. I got about 5 minutes into my ride and noticed oil leaking so I stopped to check it out. A 1 inch section of the inner clutch cover gasket blow out of the case right in front of the kick lever and all of the case bolts had loosened up. This weekend I did the repair again with a new gasket. Cleaned all surfaced really well and even used brake cleaner. No yamabond this time just the gasket. Also all new case bolts and torqued down in multiple steps to spec. I cleaned out my vent nipple that was not clogged and the hose. I reconnect the hose, but let it hang so that I knew for sure the engine could vent. I fired the bike right up, let it idle for 2 minutes and shut it off. I shined my light around the case and noticed a small oil film building around the case on the back side of the kick lever, but all of the bolts are still torqued. Anyone have any ideas besides buying new cases? I'm lost.....

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There is several posts on this gasket failure on this site and KTMTalk. The answer is to buy a Cometic gasket for about 20 bucks. The Cometic gaskets are a thin sheet of aluminum with a rubber surface on each side. These gaskets will not move or blowout. I switched to them after having two stock gaskets blow out on me causing me to loose my coolant. Slavens Racing has a video about this failure on their website. Find it and watch it.

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Buy the Cometic gasket, clean cases up real well and assemble. Your call if you want to use yamabond, I do (well another brand) around the kick starter and also up by power valve area. These are known leak areas. Torque NO MORE than 10 Nm with a known good/accurate/calibrated torque wrench. Make sure the case is sitting down the whole way and any dowels are clean. Make sure case isn't hanging up on return spring for kicker keeping it from slightly compressing gasket. I have yet to have one leak, knock on wood. I assemble this way every time problem free.

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Thanks for the quick reply! I'll take it apart this weekend.... Again :( and try the cometic gasket. Any other issues I should look for? This is my first non jap bike.

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Buy the Cometic gasket, clean cases up real well and assemble. Your call if you want to use yamabond, I do (well another brand) around the kick starter and also up by power valve area. These are known leak areas. Torque NO MORE than 10 Nm with a known good/accurate/calibrated torque wrench. Make sure the case is sitting down the whole way and any dowels are clean. Make sure case isn't hanging up on return spring for kicker keeping it from slightly compressing gasket. I have yet to have one leak, knock on wood. I assemble this way every time problem free.

id do what maztech says, id make sure youre not hanging up somewhere. the torque spec is really low, so if youre torquing it and the spring or dowels arent quite right, youre not gonna have any success IMO.

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I have a 12 250XC with 60 hours on it and have no leak. But I just learned of this problem the other day and will be replacing mine with the cometic gasket. Luckily the coolant leaks out of the motor and makes a mess but many riders are having major issues during long rides when the motor is covered in dirt and mud making the leak unnoticeable. Tons of info on this over at KTMTalk in the 2 stroke forum. This is a common issue on about ten years worth of 250 and 300 models.

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Where is everyone ordering the Cometic Gasket for the KTM 300 ?  I have read through several threads and see everyone replacing them, but no links to a quick supplier.

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You can now buy the updated gasket from any KTM dealer. Just make sure that when you get it you can see the thin layer of aluminum that is sandwiched between the two gasket surfaces. This tells you that you have the newest gasket.

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Thanks for the quick reply! I'll take it apart this weekend.... Again :( and try the cometic gasket. Any other issues I should look for? This is my first non jap bike.

 

For the cover itself, look to see if the shifter boss in the cover shows signs of wear from the end of the shifter shaft contacting it, because of little to no clearance between them. 

 

This thread starting at post #34.

http://ktmtalk.com/showthread.php?499828-Strange-Shifting-After-Slavens-Inner-Clutch-Cover-Gasket-change/page4&highlight=clutch+cover+gasket

Edited by Trailryder42

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Where is everyone ordering the Cometic Gasket for the KTM 300 ? I have read through several threads and see everyone replacing them, but no links to a quick supplier.

I bought mine from Andrew Cooksey at cookseycranks

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Yeah, the 2015 bikes got upgraded to the rubber coated aluminum gaskets now from the factory.  My 300XC has these gaskets everywhere except the clutch slave cylinder. 

 

Holy snapping crap this is good news.  A corn flake box would make better gaskets than the old style tissue paper ones KTM used.  Did they put the rubber/aluminum on the flywheel/starter gaskets also?

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And to the OP.  It will take 3 or 4 re-torques of the inner case bolts after the gasket install before the bolts hold their torque.

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Where is everyone ordering the Cometic Gasket for the KTM 300 ? I have read through several threads and see everyone replacing them, but no links to a quick supplier.

slavens has everything for ktm's

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