2016 YZ250F cam issues

Truckdriver
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Truckdriver
Has anyone else had any issues with camshaft lubricatiob?





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slipdog
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slipdog 7/25/2016 2:32pm
7/25/2016 2:32pm
Would guess something got in oil passage way to starve it from oil. Did you drain the oil and check it and the filter for debris?
JWACK
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JWACK 7/25/2016 3:06pm
7/25/2016 3:06pm Edited Date/Time 7/25/2016 3:10pm
Did you adjust the valves recently.? If you over torque the cam journal this can happen on the yamahas.
dmm698
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dmm698 7/26/2016 6:13am
7/26/2016 6:13am
The pictures kind of make it seem like theres Dirt next to the cam cap journal? I could see dirt tearing up the journals.
Charper732
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Charper732 7/27/2016 5:00am
7/27/2016 5:00am
Well that head is junk... Everytime ive seen that issue its been because the camshaft cap was not torqued down correctly. Either it was too loose or more often, too tight and the threads strip.

Its extremely easy to strip those threads. If you go into the head a lot you can still do it even when using the torque spec. When in doubt, put a timesert in and you'll never strip that.

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racinstation
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racinstation 7/28/2016 8:33pm
7/28/2016 8:33pm
I would agree with the other posts and say that it was too tight and/or is starved for oil. If an oil passage was blocked it would cause this. Also starting the bike with no oil will do this. As pointed out above, the head and the cam are now recycling material.

Truckdriver
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Truckdriver 7/29/2016 6:41pm
7/29/2016 6:41pm
Ok, new parts arrived today so I got to do a little comparis on of parts.
I found the problem of no oil. The sell ball bearing that Yamaha puts in the end of the passage they drill out for the oil to lube the cam fell out. Thus no oil pressure up top.



jaredkeller96
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jaredkeller96 7/29/2016 10:59pm
7/29/2016 10:59pm
racinstation wrote:
I would agree with the other posts and say that it was too tight and/or is starved for oil. If an oil passage was blocked it...
I would agree with the other posts and say that it was too tight and/or is starved for oil. If an oil passage was blocked it would cause this. Also starting the bike with no oil will do this. As pointed out above, the head and the cam are now recycling material.

head is defiantly salvagable...have seen heads drop valves and complete fuck everything and been repaired..take it to a reputable engine builder that does his own machining etc then it can be fixed.

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