Jump to content
Sign in to follow this  

wr426 surging - flat out 5th

Recommended Posts

Starting properly pushing my new (used) bike, and have found it to surge when accelerating under full power in 5th. It'll accelerate strongly for a little bit, then for seemingly no reason it seems to cut out or disengage for maybe half a second or less.

It will also cut out sometimes at idle - if I keep it at a slightly high idle its fine, but at a normal idle it'll sit there happily and then randomly cut out, hot or cold. I replaced the spark plug, didn't seem to help.

I've disconnected the tps and this helped somewhat with the surging issue and general manners on road, but it wasn't a complete fix for either issue.

Any ideas as to what these issues could be?

Oh and I'm using the bike as a motard with 17s on it.

Share this post


Link to post
Share on other sites

Inspect the electrical harness from Stator to plug.  Pull the tank and side panels and start going through the harness plug by plug, addine dielectric grease as you go. 

All WR's, if run for years with the stock factory corked up tuning, will get hot enough to damage the stator....or the pick up.

If it idles normally, it's not the carb, and it's not the TPS.

 

Share this post


Link to post
Share on other sites

Solved my idle cutout problem - one of the cable was pulling tight when the handlebars were turned all the way to the right, and I guess that cut off the spark somehow.

Still got my 5th gear disengaging problem - I think it might be the dogs on the gears are rounded off so it's slipping, but I'm not sure. Anyone got any other ideas?

Share this post


Link to post
Share on other sites

Feels like it cutting out but the engine isn't bogging down,  it's actually revving up and then catches with a little pull.   Tranny, it's the dreaded 5th gear issue.   My motor is on the bench right now for the same thing.   Parts get here on Friday and I'm just about to wander out and split the cases cause the mailman  just showed up with my flywheel remover.

 

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, Pinepig said:

Feels like it cutting out but the engine isn't bogging down,  it's actually revving up and then catches with a little pull.   Tranny, it's the dreaded 5th gear issue.   My motor is on the bench right now for the same thing.   Parts get here on Friday and I'm just about to wander out and split the cases cause the mailman  just showed up with my flywheel remover.

 

what parts did you order? I guess I won't really know till I split the cases, but I wouldn't mind having an idea of what I need before I do it

Share this post


Link to post
Share on other sites

3rd and 5th pinion and the 2nd shift fork.   Threw in a set of rings on the order and paid 174 for it off partzilla.  Price may be different, mine is a 2012.

Share this post


Link to post
Share on other sites

what issue does 5th gear have? I'm curious because I just plated my bike and I went on my first ride on it yesterday after working on the bike since december.

btw mines an 02 wr

Share this post


Link to post
Share on other sites

It's 5th gear not engaging properly,  it feels like a clutch slip ( quickly intermittent ).   I've done a ton of reading on it the last couple of days ( waiting for parts/tools ) .   Common causes are the missed shift to a false neutral then the shock when it jumps into gear and dropping the bike on the shifter while in gear.   I guess both of these could/can bend the shift fork.   Once the shift fork is bent the 3rd and 5th pinion gears dog teeth can not fully engage each other ( seat ) and start an accelerated wear routine.  From there it's just a matter of time before they will no longer hold the torque of the motor and " slip/catch ".

I've also read the theory that the gears just aren't beefy enough,  I'm going to call bullshit on that,  once you have them out and look at the depth of the dogs and the wear,  a misalignment by the shift fork being bent is obviously the issue.

Share this post


Link to post
Share on other sites
It's 5th gear not engaging properly,  it feels like a clutch slip ( quickly intermittent ).   I've done a ton of reading on it the last couple of days ( waiting for parts/tools ) .   Common causes are the missed shift to a false neutral then the shock when it jumps into gear and dropping the bike on the shifter while in gear.   I guess both of these could/can bend the shift fork.   Once the shift fork is bent the 3rd and 5th pinion gears dog teeth can not fully engage each other ( seat ) and start an accelerated wear routine.  From there it's just a matter of time before they will no longer hold the torque of the motor and " slip/catch ".
I've also read the theory that the gears just aren't beefy enough,  I'm going to call bullshit on that,  once you have them out and look at the depth of the dogs and the wear,  a misalignment by the shift fork being bent is obviously the issue.


Hey mate, cheers for this, finally got around to fixing it and just as you said, the 3rd and 5th have worn a smooth corner on the dogs where they engage.

However, the 2nd shift fork isn't bent at all - I'm still gonna replace it, but have you got any ideas as to what could have caused the wear on the dogs of 5th and 3rd? If it wasn't the fork, I'm worried it might be something else in there that's not right, and I don't wanna go through another set of 3rd and 5th too soon. Any ideas?

Sent from my SM-G920I using ThumperTalk mobile app

Share this post


Link to post
Share on other sites

Take a close look at the transmission bearings and how they mate with the input/output shafts of the transmission.  On my 04 both shafts had started to spin independently from the bearings causing accelerated wear on the transmission shafts... That in turn caused accelerated wear on the gear dogs.

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...