Posts
93
Joined
10/6/2016
Location
Pleasant Grove, UT, USA
Hi, I've been chasing a poorly running 2019 KTM 65 for a while now. Nigili jet kits, vForce3 reeds, OEM top end. Nothing seems to clear up an off idle bog. Sounds super lean. Suspect an air leak at this point.
I've got a leak down tester rigged up in the intake boot, exhaust plugged with a freeze plug, and plugged the power valve air vent, but it won't hold air at all. Sprayed the whole thing down with soapy water and see no bubbles on the cylinder, head, intake. Gotta be crank seal, right?
With these power valves running on air, is a leak down test even going to work?
If crank seal, should I do both sides? Can I get them without splitting the case?
I would remove the stator and spray the left-side crank seal and see if it's leaking. If you see no leak on the left side then spray the crankcase breather hose, that should tell you if it's the right-side seal without actually having to pull the cover and spray the seal directly.
It might be one or both crank seals or a leak between the crankcases.
There's a good chance it's the left side seal. The 65 has a known issue of loosing the press fit in the bearing and getting play on the left side of the crank. This play won't help the seal hold pressure of course. Take the ignition cover off, grab the rotor and see if you can detect any up/down play.
Both seals can be replaced without splitting the cases.
Thanks - have flywheel puller and seals ordered. Will report back. Appreciate it.
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Update:
Changed left crank seal and it holds air. One thing: I had my JoBlow bicycle pump on it at first, and even after changing the seal, it would still slowly leak. Changed the air pump to my shock pump and it now holds air.
Gonna get this thing buttoned up and go ride this weekend. Thanks!
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