[Jeff H]

Hi
I posted a couple of months ago about fault code 51 - cvt motor and I replaced the pulley position sensor which improved things but the problem remained
Bad weather work etc has prevented me investigating further until today when I started a final check around the bike before starting the full strip down to remove the engine to do a full cvt rebuild and I found ...... A very badly worn stopper bolt, very rounded and a groove cut into half the diameter!!
I now have a bolt on order and I hope this sorts the problem
I did not check the bolt earlier as it is a 2009 model and I thought this problem had already been sorted on previous models
I think I was only a few miles from catastrophe
If your transmission has a slight rattle ( they all do that sir) check the bolt even if it's post 2009
Ps total miles 27,000 commuting in London traffic
I have a photo of the bolt but cannot find a way to attach it to this post

Regards

Jeff

 

[Liamjs]

Interesting...

I got my 2005 six months ago and always worried about that bolt, didn't know if I needed to change it also. But for the price, I ordered one, should be in today.

Thanks for the info.

 

[DougInKY]

I too have a 2009 Burgman 650. One of the first things I did when I bought the bike was to order a new stopper bolt. Mine was okay when I bought the bike last year but I will check the thing every five thousand miles and replace as necessary.

Namaste'
Doug from Kentucky

 

[Buffalo]

I hope that fixes it but I suspect you will find the new bolt wears quickly. I've come to the opinion that a badly worn stopper bolt is not a cause for failure but a symptom that something else is wrong inside the CVT that is causing the stopper bolt to wear. I would keep a close eye on that new bolt to see if it starts showing signs of excessive wear. If it does I would tear down the CVT and check the bearings on the primary pulley.

 

[westnash]

Doesn't that put to rest the claim the more recent 650s had the problem with the cvt corrected?

 

[Ken]

I hope that fixes it but I suspect you will find the new bolt wears quickly. I've come to the opinion that a badly worn stopper bolt is not a cause for failure but a symptom that something else is wrong inside the CVT that is causing the stopper bolt to wear. I would keep a close eye on that new bolt to see if it starts showing signs of excessive wear. If it does I would tear down the CVT and check the bearings on the primary pulley.

+1. My friends 650 would destroy a bolt in less than 100 miles. Found that the input bearing was bad and the big O ring that keeps the primary pulley assy snug was also destroyed. The side to side movement of the primary pulley assy also wore a grove in the case. Lots of expensive parts but scoot has been doing well for 12K miles and 2 years. Stopper bolt has not been changed since the rebuild and still looks great.

 

[Jeff H]

Thanks for the comments
I'll monitor the bolt on a regular basis and I understand the bolt wear is a symptom of problems elsewhere, so , maybe I will be taking the engine out in the long run, but at least I now know what to look for when I do - I was thinking the plastic gears had failed, just shows how poor my diagnostic skills are
Regards
Jeff

 

[Buffalo]

The more I understand about the failures that have happened on the CVT the more I am starting to thing it is not a quality control issue on the parts but on the assembly. I can't come up with a way to prove it but I suspect the root cause of the failures that some see is the shims that position the primary pulley. I suspect that if the shimming process results in the primary pulley being close to the limit of spec it puts stress on the pulley assembly that eventually causes the bearings to fail. That would explain why some see early bearing failure and others (like me) go tens of thousands of miles with little wear on the bearings.

I know that if I every have to replace the bearings in my CVT I will take special care with the shimming process to ensure I get the best fit I can.

 

[MJR]

I hope that fixes it but I suspect you will find the new bolt wears quickly. I've come to the opinion that a badly worn stopper bolt is not a cause for failure but a symptom that something else is wrong inside the CVT that is causing the stopper bolt to wear.

Exactly because the adjuster end of the primary pulley just shouldn't be moving around.

+1. My friends 650 would destroy a bolt in less than 100 miles. Found that the input bearing was bad and the big O ring that keeps the primary pulley assy snug was also destroyed. The side to side movement of the primary pulley assy also wore a grove in the case.

Although the bearing went out on my '03 I didn't have the excess play to wear the stopper bolt and the 0-ring was still intact so that along with the lower miles is probably why the case wasn't worn allowing the adjuster end to float around like your friends.

The more I understand about the failures that have happened on the CVT the more I am starting to thing it is not a quality control issue on the parts but on the assembly. I can't come up with a way to prove it but I suspect the root cause of the failures that some see is the shims that position the primary pulley. I suspect that if the shimming process results in the primary pulley being close to the limit of spec it puts stress on the pulley assembly that eventually causes the bearings to fail. That would explain why some see early bearing failure and others (like me) go tens of thousands of miles with little wear on the bearings.

I know that if I every have to replace the bearings in my CVT I will take special care with the shimming process to ensure I get the best fit I can.

I think I reused the same shims on my '03 when I replaced the primary pulley but as I said above the o-ring that cushions the shim on mine was intact and in place. From what I've seen they used 4 dabs of RTV to hold the o-ring in place but I have seen them split and be outta place when taking one apart. This of course will allow the adjuster end to float/vibrate around wearing the stopper bolt. When I rebuilt the '03 I used a smear around the whole area the o-ring sits in to make sure it stays in place.

For anyone opening the CVT I would consider changing the o-ring and securing it like I did and while you in there and new input bearing and o-ring/dust seal afterall is it worth saving $35 if it goes out after you put it back in?

 

[Jeff H]

Well, I replaced the stopper bolt and it runs much more quiet, however, code 51 still appears
I have replaced the pps and checked all electrical connections from the cvt motor, pps and 2nd pulley speed sensor. the cvt motor runs
I start the bike with no Fi light and after about 15 seconds the cvt motor starts and the F1 light appears
If I disconnect the cvt motor and remove it, then start the engine no F1 light appears
Any ideas on what else to check before I remove the engine as there are no other symptoms of major transmission problems, could there be a glich in the ecu as it appears to be trying to change the gearing without any input from the throttle ( 15 sec delay from start up to cvt motor spinning and fault light appearing) ?
Thanks in advance for any advice
Regards
Jeff

 

[macamxthe1st]

Does anyone have any idea if this problem has been addressed/rectified on the latest 2013/14 models. Only just got mine but so impressed that I am already thinking that I would like to keep it longterm and rack up many, many miles. Oh no here comes the paranoia, again.

Geoff.

 

[Jeff H]

Just another idea - is the cvt motor switched by a relay / solenoid - is it stuck and causing the motor to run all the time - there is one shown next to it in the wiring diagram - but I cannot find any reference to the physical location - any clues?

Macamexthe1st - I have read that the transmission on the latest execs has been revised, but only in the computer control section, not the physical build, i'm sure someone will be along later to clarify
regards
Jeff

 

[macamxthe1st]

Thanks.

Geoff.

 

[Buffalo]

There were some changes made to the primary pulley assembly in the 2012 model that supposedly made it stronger.

 

[Buffalo]

The C51 code indicates either a problem with the electric motor or the controller signal to the motor.

The manual says to first check that voltage is being supplied to the motor by the ECM. You do this by putting the bike on the center stand and disabling the center stand switch. Insert probes into the CVT motor coupler then start the engine. Check that the voltage changes as the engine is reved up. If not then you either have a problem with the connection to the ECM or the ECM is bad.

If that checks OK the test the motor. Unplug the coupler then test that there is continuity between the red and black wires going to the motor.
Then test resistance between the wires at the coupler. It should be 0.8 ohms or less. If either test fails replace the motor.

If all that checks out then remove the motor from the bike. Apply 12 volts to the coupler wires and see if the motor turns. If so then reverse the wires and see if it turns in the reverse direction. If it does not do both then replace the motor.

 

[MJR]

It's one of three things, CVT motor, wiring (or main CVT fuse due to a short possibly), or controller. On a '07 I worked on it was the CVT motor (I took it out and turning by hand you could feel a spot where something inside was hitting the case) but on my '03 I rebuilt the CVT turned out to be the seperate TCU that only the '03-'04 models had (now it's part of the engine controller)

 

[Jeff H]

Thanks for the info
I checked the motor, resistance ok, spins in both directions ok, no shorting to earth so I checked the supply voltages and they change with throttle position so the ecu seems ok.
I found a second hand cvt motor on eBay so now waiting for delivery because the motor itself felt a little "lumpy" when turned by hand.
Solving the problem by substitution may prove to be expensive !!!
Jeff

 

[MJR]

It's a stepper motor so feeling distinct steps as it spins sounds normal unless there is some roughness to it. Hopefully that will fix it as the power train controller is a bit pricey.

 

[Jeff H]

Changing the cvt motor has made no difference
All the above checks show motor, ecu signal etc are all good
Now I do not know what to check
Any reasonable suggestions would be really appreciated
Regards
Jeff

 

[MJR]

Changing the cvt motor has made no difference
All the above checks show motor, ecu signal etc are all good
Now I do not know what to check
Any reasonable suggestions would be really appreciated
Regards
Jeff

Assuming the wires between the CVT motor and ECU aren't shorted (ground, power, other wires) or open then ECU is what I would suspect. The only thing I would suggest is finding another Burgman owner local to you that you might be able to swap with and by that I mean use yours in their bike to see if it's bad because if you have a wiring problem using theirs in yours could burn a good one out whereas using a already damaged one is unlikely to damage the bike it goes into but it will tell you if yours is bad.