Cold exhaust

Need advice on which oil to use or which tyre best suits you? Share your topic and get help here.
Post Reply
bogof
Posts: 21
Joined: Wed Sep 02, 2009 12:56 am

Cold exhaust

Post by bogof »

Noticed tonight that with bike on tickover, one exhaust was significantly hotter than the other.

Looking at the back, the left was hot, right cold.

Is this normal or does it indicate a problem?
User avatar
goody
Posts: 138
Joined: Sat Jun 13, 2009 1:42 pm
Location: Carshalton

Re: Cold exhaust

Post by goody »

Standard exhausts?
What part of the exhaust feels hot / cold?
Does it feel like there's an equal amount of flow out of each can?
Could be such things a partial blockages caused by collapsed rusty baffles, packing dissappeared.
Not sure if the left one flows more gasses from the rear cylinder and the right from the front but if that's the case then maybe spray a bit of WD40 or water on the header pipes close to where they exit the cylinders and see if the steam off equally maybe a misfire could cause what you're getting.
User avatar
cupasoop
Site Admin
Posts: 2687
Joined: Sat Mar 06, 2004 11:02 pm
Location: Ayrshire, Scotland

Re: Cold exhaust

Post by cupasoop »

If it's the end can that's cold then thats normal. Both exhausts flow different amounts as it's not a true 2 into 2 system (assuming a standard system), it's more 2 into 1 for a little bit, into 2.
Rich.

Image
tony.mon
Posts: 16293
Joined: Wed Jul 25, 2007 10:46 pm
Location: Norf Kent

Re: Cold exhaust

Post by tony.mon »

With the exhaust silencers off you can look down into the RH side pipe and see that there's a significant obstruction from the way the pipes are joined.
This makes it easier for gases to flow into the RH pipe than the LH one, so more gas flow to the LH and it gets hotter quicker.

Some threads in workshop section re whether this is best left alone or removed.

I cleaned mine up with one set of downpipes, but they broke up so I put a new set on, haven't bothered grinding these out yet.
Will do one day, though, as it evens out the power pulses going into the carbon cans and doesn't seem to break them up as much when there's less resistance.

That's the theory, anyway, but to be honest carbon cans on a big twin are just consumables when it comes down to it- they'll never last very long.
It's not falling off, it's an upgrade opportunity.
Post Reply