torque limiter fail , i think

[habs]

hi guys , i have a loud clunk noise when i fail to start bike , or if bike dies when wot on idle , i think when engine rotates backwerd , the limiter is not doing it's job  . please comment 

thanks

[seeeems_legit]

Can you please edit your post so it is easier to read ?

[Noble]

The torque limiter probably is doing its job.  It is a friction clutch not a 1way clutch or disengaging clutch.   It just slips a little under a sharp load. There is a torque spec for the clutch if you want to test it, but requires special fixtures to do so, so not very convenient.

[habs]

Hi Nobel , i will try to explain better , sometimes , when i try to start the bike, and take off my finger from  the start button before the engine starts , i would hear a loud hit , klunck ,metal on metal , just for a fraction off a second , like if the engine is seized , and on the second try , everything runs perfect . I this what we call kickback or reverse rotation ? and something is not doing it's job ? And no . i have no tools to test the torque  limiter

thanks  

[Johnx64]

Mine does the same thing.  I assume it's the auto decompression.

[habs]

it is really not normal noise/hit , it almost sound like piston hiting valve but only once . It will also do that if i do a really fast WOT when engine in neutral , normaly that should only kill engine (fcr 39 mx carb) but yesterday it did the same noise / hit . , it did that about 4 times in the last 3 month + 2 times yesterday .If it is the auto decompression , what would be the solution ?

 

Thanks

[Johnx64]

It's this noise at 33seconds.

[Juicenewton]

It's this noise at 33seconds.

https://www.youtube.com/watch?v=YPvuj85Ymaw

Sounded to me like your bike was idling too low and gave up. That noise didn't sound too strange to me. Just the regular shut off noise.

[Johnx64]

Sounded to me like your bike was idling too low and gave up. That noise didn't sound too strange to me. Just the regular shut off noise.

 

Not my bike and it was definitely idling a lot more than it should have been.  Just posting a video of what I think the op is describing. 

[Juicenewton]

Not my bike and it was definitely idling a lot more than it should have been. Just posting a video of what I think the op is describing.

I don't understand what you mean by idling a lot more than it should have been.

[habs]

Johnx  that noise is very similar to mine , mine could be a bit louder and very metalic ,(metal hiting metal) what is it ? and why would it hapen only a few times the last 3 month ?

 

thanks for taking the time

 

To juicenewton  , i think the bike in video was on choke and then he turned choke off and engine died .

[Juicenewton]

Johnx that noise is very similar to mine , mine could be a bit louder and very metalic ,(metal hiting metal) what is it ? and why would it hapen only a few times the last 3 month ?

thanks for taking the time

To juicenewton , i think the bike in video was on choke and then he turned choke off and engine died .

I understand that very well. It's the persons comment that doesn't make sense. I should idle high when the choke is on. When he pushed the choke in it should not drop as low as that bike. You can't idle more or less only higher and lower rpm. Edited January 11, 2016 by Juicenewton

[Juicenewton]

Johnx that noise is very similar to mine , mine could be a bit louder and very metalic ,(metal hiting metal) what is it ? and why would it hapen only a few times the last 3 month ?

thanks for taking the time

To juicenewton , i think the bike in video was on choke and then he turned choke off and engine died .

record the right noise and I'll try to help

[Johnx64]

I don't understand what you mean by idling a lot more than it should have been.

 

Oops.   I meant idling a lot lower than it should be. 

[habs]

record the right noise and I'll try to help

It 's impossible for me to record , unless it start to hapen a lot more often , the noise is very close to what you hear in video and exacly the same length , bike is 2 years old with 18000 km , never heard that before , not normal noise .

[Noble]

https://www.thumpertalk.com/shop/oem.php?partcategory=785394&manufacturer=5&category=5&year=2003&model=27297

 

Item 8 is the starter clutch.  It will make a hammer noise if it slips.

[habs]

How can i confirm that Nobel ?  I can take left cover off and try to turn starter clutch by hand , it should turn to one side but not the other , correct? also can i do that with fly wheel instaled on bike or should i remove ? is it possible for clutch to slip only a few times and then run ok ?

 

thanks

[Noble]

It is probably going to work normally most of the time. And probably get worse over time. The slip or skip puts more strain on the components.  My guess is it will eventually loosen the 6 bolts that secure it to the flywheel.  This is another possible urban myth but supposedly energy efficient (low viscosity automotive oils with friction modifiers) can lead to this type of problem. I do not know of any kind of test or even what to look for.  You might try an oil change and see if it has is any effect.  And probably a good idea to open up the stator case and check the 6 bolts holding the starter clutch to the flywheel. If they come out or break, it will ruin a stator.

[habs]

I loctied screws last year and  put paint marks on them ,  had to open cover last week , changed cam chain , screws look fine , i do oil change every 1000 km 10w40 , slow tight off road and sand riding , if it get worse ( more than 1 time a week ) i will change it , it's defenetly putting a lot off strain on everithing , i can feel it in my pants , not to say my butt ! any chance it could be torque limiter related ?

[SkymonkeyONE]

That bike is idling WAY too low.