Hi all. I recently changed my downpipes on my bike and had it mapped. After riding home I noticed 2 of the header bolts had fallen off the bike and the plate that holds one of the pipes to the engine had come loose. I've tightened them up and gone and tightened the rest up too. The problem is when I tighten them they start to bend the plates that sit on the bolts. The manual says 12nm for torque but I can't get the torque to snap out as the plate just bends before reaching the torque amount. I've attached a photo to show what I mean. The bolts are not on tight.

The bike is a CBR 600f 2013

The pipes are sat up against the gaskets and inside the lip of the engine casing. So they are in the correct place they just don't seem to want to tighten to the correct torque and stay put. Is it worth putting a drop of loctite thread lock on the bolts to stop them coming loose again? The headers are fixed in place and don't move, it's just the bolts that seem to have come loose.

Appreciate the help 👍


Look at the plates, they have a slight bend. The bolts are not on tight.

 

Hi , have the exhaust studs been fully turned into the cylinder head before the exhaust was put on, and I never trust a torque on this type of job, a good firm pinch up should suffice

 

Hi. Thanks for the reply. 👍 Yeah I made sure they were all as they should be. That's the weird thing about it. Everything seems to line up and be as it should, just the bolts don't seem as tight as they should be. I'm more bothered about over tightening them. Yeah I took the same approach as you mentioned, just tightening them so that they nip up. Do you think it's worth adding a blob of thread lock to stop it happening again? I lost 2 bolts off the same pipe, which shouldn't really happen.

 

Yes I would use a Copper based Loctite on the Studs into the Cylinder Head , it prevents a chemical reaction between the Steel and the Alloy, and makes it easier to get them out again

 

Got this stuff. Standard lock thread medium strength. This will do the job won't it? I've got copper grease on the threads. Says it will come undone with hand tools.

 

Yes its Anaerobic so that will work just fine

 

Cheers 👍 I'll put a drop on each thread.