16 yzf 250 forks sticking

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8/20/2017 9:46 AM

Trying to help a fast friend. His fork bushings are worn. What else, other than worn bushings would cause sticking in the first four inches of travel. He is young and poor so I'll be the one doing the repair work for him. I do not know Yamaha forks. Thanks Kevin Reed

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8/20/2017 10:19 AM

Kind of dumb but sometimes the forks can be slightly crooked on the axle. Try loosening the pinch bolts and work the forks up and down while the bike is on the ground. It happened to my kx 450 and the first 4 inches of travel were terrible.

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8/20/2017 10:19 AM

Binding from misaligned forks could be the cause as well

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8/20/2017 2:04 PM

yes forks are aligned, I changed seals and oil for him and his bushings were worn. He wanted to race this weekend so i put it all back together and no change in the sticking. Is it necesarry to change the internal valve oil also? Or could a seal blow somewhere?? I will put new bushings in but if there is something else I need to look for let me know. Thanks. Kevin Reed

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8/20/2017 2:33 PM

Did you tighten the triple clamps to the right torque spec?

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8/20/2017 4:45 PM

Yes upper 17, lower 14 ft/lbs

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8/20/2017 6:12 PM

Inner cartridge oil doesn't get contaminated as fast, but if his bushings are worn the bike must have quite a few hours on it. Wouldn't be a bad idea to take them apart for fresh oil and inspection while you tear the forks down again. I don't see how the inner cartridge could cause the sticking unless there's a broken part in there.

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8/20/2017 9:07 PM

The Yamaha SSS forks are very sensitive to the bushings. Old bushings will actually start affecting performance and seal life even before the show visual wear of the teflon being worn off. If you see teflon worn off they are for sure shot.

Also, the inner damping cartridge can definitely cause the problem you have. If it is not properly bled or if one of the cartridge seals is leaking you can get a stuck-down effect. Also, the plastic free pistons are known to crack and could probably cause some binding. Bottom line, it all needs to come apart and be checked.

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Powerband in every gear !

8/20/2017 9:24 PM

Ok I will inspect and replace everything I can and charge him double. Thanks for your help

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8/20/2017 10:39 PM

Kevin_Reed wrote:

Yes upper 17, lower 14 ft/lbs

Should it be ft/lbs or NM? My KTM is NM.

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8/21/2017 5:12 AM

Sounds like you were provided the wrong seals. Replace the seals again.

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