Jump to content
Sign in to follow this  

2014 crf250r front sprocket issues

Recommended Posts

First Post please be gentle, not a tech by no means but i can ride!! Over the weekend I decided to change out gearing for some 20 milers we have been riding lately, considering the 2014 motor has almost zero top end, stock is 13/49 i went with 14/51 for the fast stuff, loved the performance of the new gearing, only issue i had was that there are two washers on the stock front sprocket, NO CRUSH WASHERS? i bought bike brand new so i know it wasn't tampered with, i put BOTH washers on the rental front sprocket i went with, about 2 minutes into the trail i heard clinging noise being it was the only thing i done diff it was the first thing i check, the bolt had almost backed off sent some friends after tools i then removed the big washer and only used one, it seemed to hold up but i was still uncertain if it should have one or both washers on is there an aftermarket crush washer i need to install? can anyone help? has anyone had these issues?

Share this post


Link to post
Share on other sites

Not sure on the washers but your gearing is only half a tooth different ?

Share this post


Link to post
Share on other sites

I would guess you installed the 2 washers incorrectly. There's no "crush" washer, but there's pressure applied to the attachment system via the cupped larger inner washer. If you install any of the parts reversed, you're gonna have a problem. Specifically I bet you may have installed the inner larger diameter cupped washer backwards so there was no pressure on the sprocket, it wiggled around and the bolt easily loosened. Make sure the countershaft splines are ok.

Edited by Eddie8v

Share this post


Link to post
Share on other sites

Like 1.5 or something makes a huge difference an I drop back to the stock 13 tooth for the tights then I'm up two in the rear considering it's like 6 nuts an bolts for the rear sprocket an only one bolt to change the front, and thanks Eddie!! So do you think I should put the bigger inner washer back on?

Share this post


Link to post
Share on other sites

Like 1.5 or something makes a huge difference an I drop back to the stock 13 tooth for the tights then I'm up two in the rear considering it's like 6 nuts an bolts for the rear sprocket an only one bolt to change the front, and thanks Eddie!! So do you think I should put the bigger inner washer back on?

Absolutely put it back on! Without it I think the sprocket can flop around on the countershaft splines!!! You need to assemble the system correctly so the cupped washer places pressure onto the sprocket when tightening the bolt. And be sure to torque the bolt properly and blue Loctite with a 24hr cure might be wise. Edited by Eddie8v

Share this post


Link to post
Share on other sites

Thanks again man I've been reading your post for months I know you know your stuff!! I will try it that way, will probably be a few days before I get a chance to ride I will let you know what it's like!!

Share this post


Link to post
Share on other sites

A front is 2.5 teeth on the rear , so going one bigger on the front and 2 up on the rear has you almost std

Share this post


Link to post
Share on other sites

If stock gearing is 13-49, going up 1 tooth on the front is like going up 3.8 teeth on the rear, not only 2.5, so a change to 14-51 is bigger than it sounds...

A front is 2.5 teeth on the rear , so going one bigger on the front and 2 up on the rear has you almost std

Edited by Eddie8v

Share this post


Link to post
Share on other sites

You sure it's 3.8 it doesn't sound of feel like it

Share this post


Link to post
Share on other sites
In the 1st paragraph it clearly states the final drive ratio as ranging from 3.5 to 4.5. The chart verifies it perfectly: What is 49 divided by 13? What is 53 divided by 14? It's just basic math... check the chart for those two different sprocket setups... Edited by Eddie8v

Share this post


Link to post
Share on other sites

Sorry yes you are correct it's nearer 3.5 , the change is still only 1.5 teeth not a big change ; on my sxf 270 I went to 4.5 teeth change to make it feel different

Share this post


Link to post
Share on other sites

I used to think a tooth or two wasn't a big change, but it really is and can be felt. Big deal on a 250 when you need to keep, or move, the rpms higher or lower. I just went to a 47T rear on my 450, down from the 48T, and I noticed it right away.

Edited by Eddie8v

Share this post


Link to post
Share on other sites

I noticed a huge difference from the moment I let the clutch out (because I stalled the motor) I rarely ever do that... once we got going in the trail it was night an day difference 3rd-5th felt amazing an being that the 2014 motor has so much bottom end it didn't miss a beat!

Share this post


Link to post
Share on other sites

So I got a chance to ride this past Sunday i could not get the front sprocket bolt out by myself so i just rode it without the inner washer, it held up just fine after the ride i had a friend hold the back brake while i broke the bolt loose i put the inner washer back on with blue locktite after snugging back down i noticed the inner washer even though it is contoured doesn't even touch the sprocket so impossible for it to put pressure on it and i can actually spin the inner washer with my hand.. I'm not sure what to do now figured i would just take the inner washer back off being its not doing anything. but figured i would let you know how it worked out 

Share this post


Link to post
Share on other sites

Take a picture of things with both loosely installed. I bet you have installed them incorrectly is all, specifically the larger, inner, conical washer you may have on backwards.

Edited by Eddie8v

Share this post


Link to post
Share on other sites

Did you go crazy with the loctite and hydrolock the bolt? Make sure any loctite, lube or antisieze is only on the side of the bolt. If you get something on the tip of the bolt it can lock the bolt before it seats.

Share this post


Link to post
Share on other sites

I had the contoured side of sprocket facing me, flat side of sprocket facing bike, do I have the sprocket facing backwards?? the washers are clearly labeled saying outside

1409681482074.jpg

1409681501246.jpg

1409681516981.jpg

1409681532826.jpg

1409681548041.jpg

Share this post


Link to post
Share on other sites

I have a feeling you have an incorrect seal collar on there, perhaps too short or missing entirely, allowing the sprocket to shift right and then allowing the attachment hardware to not engage fully. Or your attachment hardware was somehow tweaked and needs to be replaced. How along is the seal collar, and does the sprocket sit flush with the end of the shaft splines?

Your chain has also left witness marks on the shifter lever...

Edited by Eddie8v

Share this post


Link to post
Share on other sites

I rode the bike about five good rides before changing sprocket, our rides are usually 40-60 mile rides, when replacing the sprocket it literally had just the sprocket, inner washer and bolt with the outer washer is made into it or whatever, so three parts. One the first ride with new sprocket w/ inner washer, it vibrated loose within minutes, I took the inner washer off and have rode over 60 Miles without a problem of the bolt backing off or getting loose. I don't know what to think.... in my mind I took a brand new bike an put brand new parts on it, it only gave me issues with the inner washer on it. I put a few more pics with this of the old sprocket as Well, also if you r wondering I clean lubricate and adjust my chain to spec every time I ride an I never ride on the roads or walk wheelies threw the neighborhood, my bikes are my life they r spotless going to a ride and get cleaned immediately after being unloaded. Should I just leave the inner washer off?

1409704184823.jpg

1409704201944.jpg

1409704211864.jpg

1409704242846.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...