What the heck is the "big end"

[oldpara]

I have a 1980 GS550, bought it for $700 and have ridden it about 500mi so far. 85 on the higway and it still has more.
It makes knocking sound which I was told not to worry about, but also it makes a cyclical rrrrr rrrrr rrrrr sound under power. Not idling.
The faster I go the faster the cycle noise is.
A service guy told me it was the big end, and ride it till something happens......
Any thoughts ? Can you explain it to me.
My second bike in three years, not exactly an old hand at this.

Thanks

[Agemax]

the "big end" is the bearing that joins the connecting rod to the crank. if the bearing has gone then riding it till something happens may prove to be very dangerous and also very expensive! i would pull the motor apart and sort the problem out right away. will save a lot of money in the long run

[tfb]

Always hard to diagnose noises with the silence of the internet... so what we need are some GS'ers in your neck of the woods who are happy to have a listen to it for you.

So, whereabouts are you located?

[dardoonk]

Always hard to diagnose noises with the silence of the internet... so what we need are some GS'ers in your neck of the woods who are happy to have a listen to it for you.

So, whereabouts are you located?

Fill in your location in your profile & GSR's will be volunteering to help you out

[SteveL-J]

Most often when the "big-end" goes so goes the motor, the last thing you want is to be tooling down the expressway at 85 and have "something happen" like the motor ceasing. Find another mechanic and get your motor checked out.

[oldpara]

Live in Keene NH