•  

    Welcome! You are currently logged out of the forum. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please LOG IN!

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the benefits of membership? If you click here, you have the opportunity to take us for a test ride at our expense. Enter the code 'FORUM25' in the activation code box to try the first year of the MOA on us!

     

How hot should my exhaust system get?

john90xj

New member
I've got a 2002 F650GS that came with a Two Brothers exhaust which is quite loud.

I found a used OEM exhaust that had both rear mounted pieces and what appears to be an intact catalyst. I installed both sides on the bike. It was noticeably quieter but it was also really hot. It heat soaked my pannier racks and the rear sub-frame to the point of not being able to touch them.

The exhaust from the the head pipe near the left peg to the cat area will reach 250 degrees F within 5-10 minutes of just idling.

How normal is this? Is it likely a plugged cat? Are there any good ways to bypass the cat? Is this junk and should I simply scrap it?

OEM Exh2.jpg
 
Most bikes don't appreciate idling for over 5 minutes; that creates a lot of excess heat with nowhere to go. Airflow is your friend.
A cat can easily be above 500º F (dunno about a dog 🐶) and more is typical for larger engines. They actually need to be hot before they start doing their job.
Whether it's plugged or not typically depends on what kind of fuel or oil has been used; sometimes rodents build nests or stash munchies inside a pipe.
You don't want to take it apart: some of the metals in there are not safe to handle or breathe their dust. (But I have heard of folks drilling thru it...)
If you can verify that it's actually "bad", don't scrap it - have it recycled (again, due to the metals).
 
Along with what is stated above, you could try reversing an household vacuum for a bit of a “flow” test.
If you decide to not use it, they are amazingly valuable to a “scrap” dealer.
OM
 
IMHO a "plugged" catalytic converter generally results in very poor running due to the restricted flow of exhaust. It seems it should also throw a code but not positive on a '02 MY. Agree, try the suggested flow test for openers.
 
It ran fine when I had it on but it was really hot, something I'd never experienced with the aftermarket exhaust. With a dB killer I found a way to quiet down the Two Brothers and won't be going back to stock. I've got $50 invested in this, maybe I can get some of it back. ;)
 
Back
Top