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CB650F Header gaskets - which way?

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
Either. I don't think it matters.

Just confirmed w/ dealer, flat side goes against the head, the little hump goes out, towards the headers/exhaust.

Otherwise you will create an exhaust leak once the head heats up from that microscopic gap!
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
Just confirmed w/ dealer, flat side goes against the head, the little hump goes out, towards the headers/exhaust.

Otherwise you will create an exhaust leak once the head heats up from that microscopic gap!
Don't want to call your dealer a liar but I don't see how that's possible since they are one piece and crushable. Whatever, but that doesn't make sense.
 

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
Don't want to call your dealer a liar but I don't see how that's possible since they are one piece and crushable. Whatever, but that doesn't make sense.
One end of the gasket has a lip, the copper gaskets they said need to have the flat end against the head, lipped end against the headers.
 

Rafe

2019
CBR650R ABS
Oct 1, 2019
United Kingdom
I remember when I did my exhaust and put the new exhaust gaskets in I did pause and thought about what direction they should go in. I can't remember what I did in the end so I obviously didn't pay that much attention to it.

The shop manual makes no specific reference to the direction (unlike other parts) so I guess it's not mission critical. Perhaps it's a mechanic thing where it's assumed they know the correct orientation?

Either way, my exhaust isn't blowing so it can't be all bad. We've read about people not even replacing the crush gaskets when changing exhausts. That's a much bigger crime IMO.
 

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
I remember when I did my exhaust and put the new exhaust gaskets in I did pause and thought about what direction they should go in. I can't remember what I did in the end so I obviously didn't pay that much attention to it.

The shop manual makes no specific reference to the direction (unlike other parts) so I guess it's not mission critical. Perhaps it's a mechanic thing where it's assumed they know the correct orientation?

Either way, my exhaust isn't blowing so it can't be all bad. We've read about people not even replacing the crush gaskets when changing exhausts. That's a much bigger crime IMO.

and then another note, I know the torque specs are 13ftlb on the 8mm header bolts and then 16lb on the 2 mounting bolts.... but how do I know the torque specs by hand? I don't think I can get a giant ass torque wrench in there.

I don't want to over tighten anything and ruin the head studs
 

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Rafe

2019
CBR650R ABS
Oct 1, 2019
United Kingdom
From the shop manual:
18 Nm (13ftlb) for the exhaust pipe joint nut
21 Nm (15ftlb) for the muffler mounting bolt

I torqued mine up using a torque wrench with a long extension bar and a universal joint adaptor (the flexible head so that you can get the angle). Undo the radiator mounting bolts to bring the rad forward to give you an extra 10mm to give you that all important space.
 

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
From the shop manual:
18 Nm (13ftlb) for the exhaust pipe joint nut
21 Nm (15ftlb) for the muffler mounting bolt

I torqued mine up using a torque wrench with a long extension bar and a universal joint adaptor (the flexible head so that you can get the angle). Undo the radiator mounting bolts to bring the rad forward to give you an extra 10mm to give you that all important space.

I'm thinking I can do 13lb by hand lol, but not sure exactly how that feels... I'm assuming pretty snug but not crazy.
I may try to use an extension and move that radiator a bit.
 

Rafe

2019
CBR650R ABS
Oct 1, 2019
United Kingdom
And just on a separate note, my copper gaskets were flat as a pancake when I took them out so does direction really matter that much?

Crash gaskets.jpg
 

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
And just on a separate note, my copper gaskets were flat as a pancake when I took them out so does direction really matter that much?

View attachment 6799
Hmmmm lol good point. I'll just see which way they were on the factory exhaust. Carefully. Cuz I know once I remove the headers they will plop right out and onto the ground.
 

Rafe

2019
CBR650R ABS
Oct 1, 2019
United Kingdom
Hmmmm lol good point. I'll just see which way they were on the factory exhaust. Carefully. Cuz I know once I remove the headers they will plop right out and onto the ground.

Trust me, they wont fall out. They need picking out so have a small pick or flat head screwdriver at the ready.

miweber929 @miweber929 - worth a move to the exhaust thread?
 

koofdome

2018
CB650F
Apr 27, 2020
Chicago, USA
Riding Since
2018
Trust me, they wont fall out. They need picking out so have a small pick or flat head screwdriver at the ready.

miweber929 @miweber929 - worth a move to the exhaust thread?

So update, i could NOT get those dam OEM gaskets out. They are smashed in the head lol. Impossible to pick out even with a dental pic I use to clean my guns from gunk.

considering the bike only has 1,327 miles I felt okay using OEM ones. Torqued the bolts down slightly over 13lb just to be safe. About 14-15lb

no leaks, and sounds so badass. Love the new TBR exhaust.
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Old gaskets need careful application of a flat blade screwdriver to remove.

Over torquing nuts in an area subject to high heat (and therefore expansion) is not recommended.

Glad you like the exhaust though!

J
 

miweber929

2014
CBR650F
650 Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Riding Since
1975
considering the bike only has 1,327 miles I felt okay using OEM ones.
Tons of info on here already, some you’ve even provided, show these gaskets are not mileage dependent at all but are single use, crush gaskets that form to the shape of the manifold and head to seal out any imperfections. Once there are crushed to seal the OEM pipe, they should be replaced

They are a bitch to get out but will come out. You may be fine, you may not, time will tell. Enjoy the pipe!!!
 
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