How Far Do You Guys Go Before Replacing the Crank on a 450?

Moto520
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Moto520
How many hours are you guys getting on these?
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kb228
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kb228 4/12/2021 3:16pm
4/12/2021 3:16pm
Doesnt matter. Only thing that matters is bearing play
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bh
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bh 4/12/2021 6:16pm
4/12/2021 6:16pm
I did 100 hours on my 19 kx450, but depending on who you ask they have rod problems.
Rickyisms 4/12/2021 8:17pm
4/12/2021 8:17pm
kb228 wrote:
Doesnt matter. Only thing that matters is bearing play
Yup.

Depends a lot on the bikes too, lots of stories about average vet riders getting 200+ hours out of Austrian 450s before they ever get opened up for valve adjustments. There’s a rider who is active on thumpertalk and pops in on here by the name of Monk who is a AA off-road guy who had a 2016 350XCF that didn’t even get a piston until around 500 hours I believe.
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DynoDan22
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DynoDan22 4/12/2021 8:21pm
4/12/2021 8:21pm
Monk gave that '16 350 to his wife when it had 525hrs. He said he never opened the motor. Haha.
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Moto520
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Moto520 4/13/2021 7:57am
4/13/2021 7:57am
DynoDan22 wrote:
Monk gave that '16 350 to his wife when it had 525hrs. He said he never opened the motor. Haha.
Legend
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Moto520
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Moto520 4/13/2021 7:59am
4/13/2021 7:59am
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but mine feels fine so i think i'm going to leave it and let it ride.
Moto520
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Moto520 4/13/2021 8:01am
4/13/2021 8:01am
Moto520 wrote:
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but...
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but mine feels fine so i think i'm going to leave it and let it ride.
I'm pulling the motor apart = the motor guy that i paid is pulling it apart
btroxler
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btroxler 4/13/2021 9:53am
4/13/2021 9:53am
It depends on couple variables:

a.) How do you ride? Are you on the rev limiter all the time or do you lug?
b.) How well do you maintain you engine? Oil and filter changes etc


If you are an average B/C rider who lugs you could go 100-150 hrs. If you are an A rider that is on the rev limiter all the time I would say 50 hrs.

Like anything else it is cheap insurance, like oil changes. If the rod breaks it is going to cost you a lot more than a rebuild crank and even a new OEM crank.
captmoto
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captmoto 4/13/2021 12:33pm
4/13/2021 12:33pm
I know a guy that did Baja tours on a KTM. He sold a 525 I think with 400 + plus hours and was never opened up. He also has a 450 exc with almost 600 hours on it.
kb228
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kb228 4/13/2021 1:26pm
4/13/2021 1:26pm
Moto520 wrote:
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but...
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but mine feels fine so i think i'm going to leave it and let it ride.
If youre paying a guy you should let him examine it and give you his professional opinion. Too many variables to answer these questions on a forum. For example im slower than balls and i would fully expect over 200 on my 450
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RCF
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RCF 4/14/2021 5:55am
4/14/2021 5:55am
I sold one of my kids race bike (ktm 250 xcf ) with 500 hours on it and the original crank the new owner rode it for two years before having to put a new crank in it.
rjg
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rjg 4/14/2021 7:01am
4/14/2021 7:01am
Monk is fast and knows what he is doing. You can stretch these motors longer than you think.
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Moto520
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Moto520 4/14/2021 9:31am
4/14/2021 9:31am
Moto520 wrote:
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but...
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but mine feels fine so i think i'm going to leave it and let it ride.
kb228 wrote:
If youre paying a guy you should let him examine it and give you his professional opinion. Too many variables to answer these questions on a...
If youre paying a guy you should let him examine it and give you his professional opinion. Too many variables to answer these questions on a forum. For example im slower than balls and i would fully expect over 200 on my 450
That's the thing.....you can pretty much just give it the tug and eye test. There's no way to tell if a crank is going to go bad within the next 5 hours if it passes the tug and eye test.
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Moto520
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Moto520 4/14/2021 9:32am
4/14/2021 9:32am
Moto520 wrote:
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but...
I'm pulling the motor apart at 82 hours for a top end/ valve job. I'm at the point were i would normally throw one in but mine feels fine so i think i'm going to leave it and let it ride.
kb228 wrote:
If youre paying a guy you should let him examine it and give you his professional opinion. Too many variables to answer these questions on a...
If youre paying a guy you should let him examine it and give you his professional opinion. Too many variables to answer these questions on a forum. For example im slower than balls and i would fully expect over 200 on my 450
My motor guy says to run it.....
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