[79TA7.6]

We have 4-5 1986 era TRX250 utilities on the farm and now one 2001 TRX350TM. All except for one when you shut it off has a whine. The 350 is not all the time, but still does it. From what I have read this is the sprag bearing for the starter. I assume the dogs are not spreading out from the spinning force. I have also read that these are no longer available for the older 250s but you can take two different ones to build them.

Like I said, one of the 250s does not do it and I would like to know what causes this before it does start. Same with the 350, maybe prevent it before it gets worse. Does anyone know why these bearing fail? Or is it something else that we hear? In order to keep the ones that spin all the time from doing it, we will drop them back into gear when we shut them off. This I am assuming is not good either. We try not to run the ones that do this, but sometimes have to when running the cows.

Any input?

 

[ktriebol]

The starter gear does have a sprag bearing, but that is not what you are hearing. There is also a sprag bearing on the centrifugal clutch, and that is the one that makes the whining noise that you hear. If you think of it, the starter gear only turns when you start the machine. Once running, the starter gear is stationary, so it cannot make a whining noise.

Reports of the whining noise from the centrifugal clutch after shutdown are fairly common. It just means that the sprag bearing has failed and needs to be replaced. I don't know what makes them fail other than normal wear and tear. I have never had one fail on my Rancher or Foreman.

 

[shadetree]

centrifugal clutch bearing, they wear out over the years. dropping it into gear will cause damage elsewhere..please do not do this !. yes, they are discontinued today. they are better known as one-way bearings.

 

[79TA7.6]

The reason we were thinking it was for the starter is that when they do fail, they become a pain to start. Using the kick start becomes serious hit and miss, and even the electric starter sometimes won’t grab. Why would this be?

 

[fishfiles]

two ways I find you can tell your one way bearing is going out , when you turn the engine off the bearing will whine down for a couple of seconds after the engine is killed and when you are under power and let off the throttle in gear , there is no engine braking , the bike rolls freely

 

[79TA7.6]

two ways I find you can tell your one way bearing is going out , when you turn the engine off the bearing will whine down for a couple of seconds after the engine is killed and when you are under power and let off the throttle in gear , there is no engine braking , the bike rolls freely

When doing this it is generally the clutch bearing?

 

[fishfiles]

number #25 in this print , it is still available , make sure if you change it , that you put it in the correct way ----another thing is when it goes all the way out , you can't kick start it


https://www.partzilla.com/catalog/honda/atv/1986/trx250-a-fourtrax-250/clutch

 

[79TA7.6]

Thanks fish. That makes sense as the bike that has the problem the worse refuses to be kick started. Have to easily turn it over until you find the spot where it wants to grab.