[Ande780]

I was on the track yesterday, all was fine for about the first hour or so and then I noticed that my bike was really hard to shift into 3rd gear. It would go from first to second easy as usual and then when I tried going into third, it just wouldn’t shift until about my 5th or 6th attempt but I was slowing right down. I kept trying and trying and I ended up going off of a jump and when I came back down I felt something In the bottom up kinda make a clunk feel and then it would shift normally. Shortly after it had issues shifting into third again. Not sure what would cause this but maybe somebody has got some ideas??

[Aussiecrf230]

What model and year is the bike?
Has it ended up on the shifter side recently and hit the shift lever?

[Ande780]

It is a 2005 Honda crf450r. And no it hasn’t. I verified that the shifter isn’t hitting the case either

[Leardriver]

I have seen a bent shift fork cause what you are describing.

[Back2-2]

2nd the bent shift fork.

[Ande780]

So how should I go about checking that? I’m
Not too experienced on the bottom end of the motor? And I didn’t crash it or anything so is there any reason why it would bend?

[Back2-2]

It happens from hard force against the shift drum and usually results in opening / bending the shift fork. Can be a over excessive force while pumping on the shift lever up or down, from a crash which transmits force to the fork & drum. It could be from landing from a jump with your foot on the lever transmitting undue forces on the shift fork & drum. It could just be wear from use.
If you have never had a lower end apart it's going to be a intimidating job. Much depends on your mechanical skill level.
I would do some more investigation before jumping to any conclusion. With the bike on a stand statically going through the gears as you rotate the rear wheel. I would also try in on the stand with the bike running and see what you find.
It is certainly something that need to be investigated fully before going in.