Ktm 65 sx stuck in 5th gear

SOURCE: ktm 125 sx 08 stuck in 1st gear

You have a bent shift fork and possibly something else going on. The engine will need to come out of the bike. Remove the top end, the flywheel and electrics, the clutch, the shift mechanism and kick starter and a few other parts. THEN you are ready to split the gearbox to get to the crankshaft, gears and shift forks.
You will need an impact driver, flywheel puller, case splitter, torque wrench and factory service manual, plus the normal screwdriver, pliers, etc.. Alternate to the special tools is taking it to the dealer and say "Fix it". I often tell people to take it to the shop just so they don't get into such an involved project and they now have a knowing eye and experienced hands working on the problem.
The repair cost will probably be $800 or so.

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SOURCE: how much gear oil does an KTM 85 hold and how do

there should be a sight glass on the gear box to the rear of the casing. The oil should be of an opaque appearence, Sorry can not supply the capacity, try your local dealer for an answer on that one

SOURCE: my ktm 65 sx gear shift wont select down

not sure bout that bike specificaly, probly there is a spring on the gearshift shaft , or something to return the lever and shift drum back whenever actuated. no matter what it is, you gotta split the cases to fix it .

SOURCE: I got a 2010 ktm

Thank you for contacting FixYa with your KTM Inquiry.
More than likely you have a jetting problem. My first thought would be to call the dealer service department and ask what jetting they suggest for the local area you are riding. May or may not be able to advise you and want you to bring it in. Check your user manual and see if any jetting suggestions exist. Pretty easy do it your self fix.
Start by cleaning your air cleaner so it's not drawing excessive fuel to air mixture. Replace fuel filter and confirm gas tank vent tube is not pinched or plugged.
Steps:

1. Idle - if it's fat at the bottom it will gurgle and overload and has tendency to run bad and stall at start. Adjust the air screw out about 1 1/2 turns. May need smaller jet size.
2. Middle - Needle Jet and Tower. If it runs bad at half throttle to 3/4 this may be allowing over fueling. Simple fix is to lower the slide cir-clip holding the slide to a lower notch allowing the needle to project further down in to the pilot and leaning out the mixture bypassing the needle.
3. Main Jet - Allows for optimum speed when you have the wire tight at high rpms. If it's fat and not running right go down a size on the main jet. Engine should have a smooth scream.

SOURCE: I have a 1998 ktm 65 sx I just bought it when we

Thank you for contacting FixYa with your inquiry.
The first thing we need to do is eliminate the possibility that the shift lever is not interfering with anything limiting it's travel into the top three gear positions. It's possible that the lever is bent or has been incorrectly re-installed on the wrong spline position.
That being said, we more than likely have a problem with a bent shifting fork, a pall, or a shift rail, maybe even a broken gear.. There is also a good possibility the engine has been previously disassembled and not had parts replaced and the engine did not get re-assembled correctly. You will have to remove the engine and split the case to inspect the shafts, shifting forks, spacers, and shifting drum to correct the problem. This link will take you to the complete shop repair manual for this bike. Check the section 4 beginning on page 36-37.
http://www.scribd.com/doc/44875530/20355873-1998-03-KTM-60-65SX-Service-Manual
You may have to make some holding parts and/or rent some pullers but it's not to bad of a project. A good KTM Shop can always fix the problem but it's expensive. This is a great little bike. I'm sorry it's having problems.
Thanks again for contacting FixYa.
TF