Jump to content

fluttering in 5th gear?

By japcraplover89,
in YZ400F/426F/450F/450FX

 Share

Recommended Posts

Newbie

japcraplover89

Posted
Posted

hey all, new to the forum but not new to riding or racing moto for what that matters, but im having a problem with my bike. in 5th gear my bike (2010 yz450f) starts to flutter out, almost like the RPMs are still riding but it wasnt catching gear. i ordered a new clutch which isnt here yet, but i ordered it thinking maybe my clutch was slipping since its the bikes stock clutch of two seasons now. after pulling the clutch, it doesnt appear that my clutch is toast. now im wondering if i have a flat 5th gear? has anyone else had a problem like this?

Tyler.

Link to comment
Share on other sites
Grand Master

sonobob

Posted
Posted

Welcome.

Can you give more details? Anything and everything you can think of, even if it might seem irrelevant. Altitude? What type of terrain? How fast are you going in 5th when you notice the problem? It only does it in 5th gear? Answering all of these may or may not help, but the more info you can give, the better.

A guess is all I can venture at this point, but from what you've described, it seems to me that if your clutch were failing, the problem would be occurring in every gear.

Sorry I couldn't be more help at this point.

Link to comment
Share on other sites
Newbie

japcraplover89

Posted
  • Author
Posted

it happens while riding track if i get a long enough straight to touch 5th gear, id say at speeds of 45mph? which is fairly low 5th. not that i had to touch 5th, but i was trying to pin point what the problem could be last weekend by playing with 5th. its like when i get to 5th, even though my RMPs arent screaming, theres some sort of throttle restrictor not allowing the bike to continue gaining momentum. i took the bike out on sunday after the problem arose on saturday, and had plenty of opportunity to play with higher gears while trail riding and it just seem to be worse. the bike runs fine with no problems in 1st-4th, 5th gear just seems to be finicky. ill install the Hinson when i get it on friday and test it out on saturday to see if the problem is still there, at which point ill be splitting the case and taking a peek at the gears. i just dont see why 5th would be burnt already, as i rarely use it unless im at the dunes or somewhere else open, which isnt often since most tracks in my area dont require 5th gear.

Link to comment
Share on other sites
Rising Star

eazrider

Posted
Posted

From what you are describing, You need to replace 5th gear, which consists of 2 gears. Since you have kept riding with it jumping in and out of gear, be prepared to replace the shifrt drum (cam) and a shift fork as well. When your bike is acting like you are describing this one, continuing to ride, and jump in/out of gear, insures damage to components that might not yet be damaged

Link to comment
Share on other sites
Grand Master

grayracer513

Posted
Posted

Doesn't sound like it to me. Not the way it's described:

it happens while riding track if i get a long enough straight to touch 5th gear, id say at speeds of 45mph? .... its like when i get to 5th, even though my RMPs arent screaming, theres some sort of throttle restrictor not allowing the bike to continue gaining momentum..

If it was 5th gear popping in and out, it would be accompanied by a harsh jerking sensation, as if the chain were jumping over the sprocket, or you were rapidly fanning the clutch.

If in fact it is, though, the gears you would need would not be both gears for 5th. You would need the 5th and 3rd gear pinions (on the main shaft) and the number 2 shift fork. There's very little reason to suspect the shift cam of being damaged.

Link to comment
Share on other sites
  • 11 months later...
Apprentice

ScottYo

Posted
Posted

hey all, new to the forum but not new to riding or racing moto for what that matters, but im having a problem with my bike. in 5th gear my bike (2010 yz450f) starts to flutter out, almost like the RPMs are still riding but it wasnt catching gear. i ordered a new clutch which isnt here yet, but i ordered it thinking maybe my clutch was slipping since its the bikes stock clutch of two seasons now. after pulling the clutch, it doesnt appear that my clutch is toast. now im wondering if i have a flat 5th gear? has anyone else had a problem like this?

Tyler.

 

 

My 2010 YZ450 just started doing exactly as described. Did you ever figure it out? 

Link to comment
Share on other sites
  • 3 weeks later...
Apprentice

ScottYo

Posted
Posted

Crapolla!

 

Im going to pull the motor and split the cases this weekend. Hopefully the cause will be apparent.

 

Also researched the possibility of swapping for a WR 4th and 5th, Looks like you need the whole WR gear set as the splines are different.

Link to comment
Share on other sites
Community Regular

yam314

Posted
Posted (edited)

Turns out, my bike broke 5'th gear instead of 4'th as I had originally posted. i found the broken part when i pulled the flywheel. It was magnetically stuck to the flywheel.

Edited by yam314
Link to comment
Share on other sites
Apprentice

ScottYo

Posted
Posted (edited)

Not true. You will need the WR (or Gen2 YZ450) output shaft and the 4 gears that make up 4th & 5th. That's it.

 

 

Oah... Because 1,2,3 are Pinion / Idler gears on the output shaft, got it!

 

Would you be willing to help me out a bit further and identify part numbers? is a 2010 gen2? I have a 2010. Figured a 12 WR 450 would be good to source gears from?

 

 

Here is the 10 Yz 450 trans...

10_YZ450.jpg

 

Here is a 12 WR 450 Trans...

Imagewr450.gif

 

 

So I need...

 

Output Shaft 

 

13: DRIVE AXLE ASSY -- Part# 2S2-17402-00-00
17: GEAR, 5TH WHEEL(21T) -- Part# 5TJ-17251-20-00
23: GEAR, 4TH WHEEL (21T) -- Part# 5TJ-17241-20-00

 

Drive Shaft

 

3: GEAR, 5TH PINION (25T) -- Part# 5TJ-17151-20-00

7: GEAR, 4TH PINION (22T) -- Part# 2S2-17141-00-00

 

 

Thanks!

Edited by ScottYo
Link to comment
Share on other sites
Apprentice

ScottYo

Posted
Posted

20140322_141426.jpg

 

 

 

If you want only the WR 4th and 5th, your numbers are correct, except that the 4th pinion has changed up to # 2S2-17141-20-00. 

 

There was a discussion of this matter earlier: https://www.thumpertalk.com/topic/954114-wr-4th-5th-on-a-10-yz450f/

 

 

Well.... it all looks okay to me The 5th wheel has a little scuffing where pinion engages but...  iduno . Any opinion?

 

!Thanks -Soctt

 

 

 

20140322_141439.jpg

 

 

 

 

 

 


 

Link to comment
Share on other sites
Apprentice

ScottYo

Posted
Posted

The 5th wheel doesn't play an active part in engaging fifth.  That function is done by the 3rd pinion.  The drive faces in the 5th pinion, and a bent fork are the usual suspects.  Look for wear at the center of the fork. ( ---> C ), usually means it's bent.

 

 

Hello GrayRacer, thank you very much for your help! I greatly appreciate it!

 

here are a few more pictures, shift fork and the wear pattern seem to look okay, I got a better picture of where the 3rd gear pinion engages the 5th wheel. I just ordered the WR 4th and 5th, output shaft and a YZ 3rd pinion, and shift fork 2 i dont see any glaring problems but hopefully just throwing some parts at it will cure the problem.

 

20140322_183417.jpg

20140322_183515.jpg

 

20140322_183649.jpg

Link to comment
Share on other sites
Grand Master

grayracer513

Posted
Posted

Are you sure that transmission was skipping in and out of 5th?

 

The fork looks immaculate.  Don't try to juggle with the whole transmission right now, just set up the main shaft, the shift cam, and the forward shift fork in the right crankcase half to find out how deep the 3rd pinion engages in the 5th pinion. 

Link to comment
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:

ThumperTalk

Register a new account Sign In Now
 Share
Go to topic listing
×
×
  • Create New...
Terms of Use
Copyright
Privacy Policy