Bent header bolts

[Berlin Germany]

OEM header bolt. Bent.

View attachment 1559780

very strange that the bolt is bent.

personally, I can only imagine. that it was first screwed in completely unevenly and then tightened with far too much torque.
they get 15-20 Nm,

so when installing 15 Nm and then during the first engine test run, when a manifold chirps, a little more - until the chirping stops.

I guess I've had these bolts out and screwed back in on at least 100+ Busas.

never a single one was bent.

what I always do is coat the thread with (ceramic) anti-seize that is resistant to temperatures up to 1200°C.

 

[Dustin02]

I had 2 bent header bolts on my Gen3. None on my 2008 B-king.

 

[kim windsor]

I had 2 bent header bolts on my Gen3. None on my 2008 B-king.

Dustin I may be in town after Wednesday next week

 

[Dustin02]

Dustin I may be in town after Wednesday next week

Give me a holler when ya get in.

 

[fallenarch]

If bending is this common, then there is a good chance it was designed that way (or an oversight obviously). I think I would prefer to let the bolts bend than the head or pipe welds crack. Especially since a good seal here is not critical (Yoshi even says to remove the gaskets). I was talking to Sato about switching the bolts out for Ti and got a lecture. "These bolts are used for a purpose - they are engineered for a specific yield curve so they break instead of your frame." That being said, man, those Tis look sexy - do as I say, haha

 

[Berlin Germany]

If bending is this common, then there is a good chance it was designed that way (or an oversight obviously). I think I would prefer to let the bolts bend than the head or pipe welds crack. Especially since a good seal here is not critical (Yoshi even says to remove the gaskets). I was talking to Sato about switching the bolts out for Ti and got a lecture. "These bolts are used for a purpose - they are engineered for a specific yield curve so they break instead of your frame." That being said, man, those Tis look sexy - do as I say, haha

please write that your above comment is meant to be completely ironic - or is it not??

otherwise - a bent srew ALLWAYS shows ,
that st. went totally wrong while assambling.

a screw / bolt is allways calculated to stay straight and never to get bent (how ever) wile in use.

 

[fallenarch]

please write that your above comment is meant to be completely ironic - or is it not??

otherwise - a bent srew ALLWAYS shows ,
that st. went totally wrong while assambling.

a screw / bolt is allways calculated to stay straight and never to get bent (how ever) wile in use.

What I said was correct. If it is a regular occurrence, then the bolt is not strong enough, which could be on purpose or by design error. It's possible they cut it too close on the yield strength to be sure something else does not get damaged. So I will stand by that. We do this all the time in building design, it's called progressive collapse.

We tend to think of a bolt as a bolt, which is not the case. There is more to it than size, weight, cost, aesthetics, and corrosion resistance. Will your bike explode if you use the wrong bolt? Nope. But I have absolutely seen stuff break because of the wrong fastener.

 

[Dennis]

Every Gen2 that I have pulled the stock exhaust bolts out of had at least two bolts bent like shown. Clearly Suzuki doesn't use very sophisticated torque monitoring during assembly of this joint. I keep a handful of these bolts on hand so I don't have to chase them when needed.