2014 yz250f locked up bent cam shaft?

3/7/2016 5:54am Edited Date/Time 4/3/2016 9:39am
Hey guys little bit of background I have a 14 yz250f with 26 hours on the bike valves were checked and in spec at 23. They were actually right on spec. bike locked up


UPDATE: so the dealer has said the cam shafts look bent. What could of caused this?
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Rowlands
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3/7/2016 6:00am Edited Date/Time 3/7/2016 6:37am
What map did you use, made up one or have you been given it, aslong as you have stayed within the the limits of the maps that GYTR state in the manual it should be fine.(I don't know these limits)

I am sure it can have an effect if used incorrectly. I hope you get it sorted ASAP
BobPA
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3/7/2016 6:03am
Could you post a few pictures of the engine? I highly doubt the map change would make a valve drop.
luckyguy19
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3/7/2016 6:03am
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
hillbilly
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3/7/2016 7:02am
Can you or did you alter the rev limit?

Check the spring heights and see if that one collapsed.

The Shop

Team Ideal
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3/7/2016 8:12am
luckyguy19 wrote:
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
this
hillbilly
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3/7/2016 8:47am
luckyguy19 wrote:
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
Team Ideal wrote:
this
Not if the spring broke or sagged out .
mxrose3
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3/7/2016 9:01am
hillbilly wrote:
Not if the spring broke or sagged out .
Hillbilly knows whats up..
mxrose3
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3/7/2016 9:02am
Hey guys little bit of background I have a 14 yz250f with 26 hours on the bike valves were checked and in spec at 23. They...
Hey guys little bit of background I have a 14 yz250f with 26 hours on the bike valves were checked and in spec at 23. They were actually right on spec. bike locked up


UPDATE: so the dealer has said the cam shafts look bent. What could of caused this?
Were you at Elizabeth City this weekend?
luckyguy19
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3/7/2016 9:05am
luckyguy19 wrote:
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
Team Ideal wrote:
this
hillbilly wrote:
Not if the spring broke or sagged out .
That would still be a mechanical failure, not something caused by the tuner. You cannot change the rev limiter with the tuner, so there is no way for it to contribute to a keeper or spring failure. I could see detonation being cause by a poorly tuned map, but that would effect the bottom end, not the valve train.
3/7/2016 10:09am


I'm using the second map setting on this sheet hard hitting map.
3/7/2016 1:21pm
Looks like Yamaha is gonna step up and take care of it. Will share result, exact reason I went with yami.
kiwifan
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3/7/2016 3:07pm
Looks like Yamaha is gonna step up and take care of it. Will share result, exact reason I went with yami.
Then its a manufacturer defect if thats the case, they wouldnt go near if it it was caused by the tune
GuyB
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3/7/2016 3:11pm
Looks like Yamaha is gonna step up and take care of it. Will share result, exact reason I went with yami.
Did I shoot a photo of this engine apart in Atlanta?
blusmbl
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3/7/2016 3:23pm
Yes it could, but highly unlikely, and even less likely if it was a calibration from GYTR.
hillbilly
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3/7/2016 4:38pm
I have seen detonation cause the exhaust valve to gaul in the guide from heat,it sticks open and things start coming undone.

This wad in a v8 dragracer I was building, the detonation came from oil being drawn in thru a hairline crack in the piston.

Oil lowers the octane and it was a l3 to l compression so it failed real quick like.
3/7/2016 4:49pm
Looks like Yamaha is gonna step up and take care of it. Will share result, exact reason I went with yami.
GuyB wrote:
Did I shoot a photo of this engine apart in Atlanta?
No I was at ncmp this weekend.
526
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3/8/2016 4:50am
luckyguy19 wrote:
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
Unless you float the valves in a OVER rev situation and the keeper pops out, Floating the valves unloads/untensions the valve springs and the tension of the valve spring is what keeps the keeper in place.
luckyguy19
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3/8/2016 5:49am
luckyguy19 wrote:
No, it was not caused by the tuner.

A keeper failing is a mechanical defect, not the result of a tune.
526 wrote:
Unless you float the valves in a OVER rev situation and the keeper pops out, Floating the valves unloads/untensions the valve springs and the tension of...
Unless you float the valves in a OVER rev situation and the keeper pops out, Floating the valves unloads/untensions the valve springs and the tension of the valve spring is what keeps the keeper in place.
Yes this is also possible, but again, not caused by the tuner.
3/8/2016 6:59pm
So a update we took the cover off and valves r in spec bike seems to be semi locked when pushing the left intake valve in stroke seems off like maybe it's bent and could be hitting piston. Anyone ever have anything like this?
kripple428
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3/9/2016 8:24am
Well if it stuck open just a tiny fragment of a second too long for whatever reason and got knicked by the piston it's possible that it just got bent instead of breaking. I see it a lot in cars. Need to pull the head and remove all the valves inspect the valves and piston
hillbilly
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3/9/2016 9:08am
So a update we took the cover off and valves r in spec bike seems to be semi locked when pushing the left intake valve in...
So a update we took the cover off and valves r in spec bike seems to be semi locked when pushing the left intake valve in stroke seems off like maybe it's bent and could be hitting piston. Anyone ever have anything like this?
If it is bent then it wont be returning to the cam lobe,you shoulda seen a lot of clearance there with the lobe up before removing the cam.
TallCan 16
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3/9/2016 9:31am
On the topic of detonation, looking at their fuel recommendation in the chart above... Would you rather use premium 10% ethanol blend pump gas or mid-grade ethanol-free? There is a gas station around me that sells ethanol-free gas but only in mid-grade.
BobPA
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3/9/2016 9:39am
TallCan 16 wrote:
On the topic of detonation, looking at their fuel recommendation in the chart above... Would you rather use premium 10% ethanol blend pump gas or mid-grade...
On the topic of detonation, looking at their fuel recommendation in the chart above... Would you rather use premium 10% ethanol blend pump gas or mid-grade ethanol-free? There is a gas station around me that sells ethanol-free gas but only in mid-grade.
Premium
luckyguy19
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3/9/2016 3:28pm
If there was piston to valve contact, I would strongly consider replacing the crank as well.
hillbilly
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3/10/2016 3:49am
Dumped the oil and filter today had metal in it.
Was the bike in time,the marks on cam and crank lined up? The cam chain tight against the tensioner?

Oh,and does that cam have a press on gear? I cant remember, if it does the marks would still line up but the cam can slip in the press on gear and be out causing parts to hit.

If the filter was covered in metal and went into bypass then you got to clean shit out good. Cut the filter oppen and unfold,see how much is in it.

cpj36
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3/10/2016 10:21am
I know better than to start valve spring debate but spring pressures at 26 hours would be a concern for any of the fast guys...a tuner does affect valve & seat temperatures
3/10/2016 3:05pm
Well Jarman Motorsports in Charlottesville va where I purchased it is tearing it down and doing everything they can for me should know in a few days. Their pushing yami to step in. Best dealer and people I've ever dealt with.
3/15/2016 12:49pm
so the dealer has said the cam shafts look bent. What could of caused this?

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