Exhaust condensation

[Nurse Julie]

Hi Chaps

Just started bike up and there is small puddle of sooty/ watery condensation on the floor under where down pipe No.1 joins the collector box. This wasn't there before I started it up from cold but noticed it the other day also when starting up. Last time I took it out I did about 100 miles and thought that would be plenty of miles to burn off any condensation in the pipes.I have had a quick feel along the collector box and the silencer and cannot find any drain holes so I'm assuming the water collects as bike is cooling down and can't find it's way out till I start her up again. Should there be a drain hole somewhere and why didn't this happen last year ?. I had system off over the winter and other than fitting new exhaust packing between 1 and 3 and the collector to the silencer, nothing has changed. Any ideas?

Ta in advance
Julie x

[Nurse Julie]

It is definately sooty water, not oil or fuel

[tom400f]

Hi Julie

I know your silencer is a pattern one but may be they replicated the pinhole just behind the collector joint on the silencer itself. There is no drain orifice in the collector or the downpipes.

After a run I wouldn't expect any water to be in the system. It is hot and there is no combustion so no water vapour. When you start from cold though, of course the water vapour condenses in the cold exhaust system giving the white puffs and doubtless some puddles from that pinhole. It's tiny but it's there (on OEM units anyway). Make any sense at all?

[tom400f]

... though looking at your pic may be your downpipe joints are blowing...

[Tiny Tim]

The motad on my 550 does the same thing until it's warmed up. The leak appears to come from where the down pipes slide into the exhaust itself.

[petersy]

The motad on my 550 does the same thing until it's warmed up. The leak appears to come from where the down pipes slide into the exhaust itself.

Yes, my CB550 does the same on starting up.

[motad_uk]

The motad on my 550 does the same thing until it's warmed up. The leak appears to come from where the down pipes slide into the exhaust itself.

don't know how long your system has been on- but I would expect any weeps to be sealed within 500 miles as the joint carbons up. May be worth just checking that the pipe is snug into the collector and even (rarely needed) a wipe of exhaust paste on the joint after removal just to stop any tiny movement

[Nurse Julie]

Hi Ian.
I have probably only done about 300 miles since refitting the system. I will have to be a bit more patient I expect 

Regards
Julie

[UK Pete]

When i done my F2 and started it for the first time i was horrified at the amount of water that came out of it, if it were watercooled i would have sworn it had a leak, but after it was run for a while it never repeated the huge puddle just the odd bit here and there, i wonder why they do that
pete

[Trigger]

It is definately sooty water, not oil or fuel

Can't you toilet train your bike 

[Lynx]

My 400 is exactly the same. I've never understood why so much water comes out the exhaust on these. If I've had the bike idling for a while, say to balance the carbs, it is especially bad.

[mickwinf]

My bike has a little wee every time I start, I think its true that for every gallon of petrol burnt a gallon of water is produced, so not suprising that some leaks through any small gap until the engine and exhaust get hot enough. Many exhausts have a small hole at the lowest point to let it drain out, just looked at my 500/4 nos exhaust in my bedroom(!!) and they have them.

[Clem2112]

Yes, they all do it from a cold start.
Following cars you often see the tailpipe piddling on the road for a while.
Could it be made worse by the water that the ethanol in modern petrol absorbs ?

I expect more weeps when I fit the replica Motad headers and collector to my bike.
Those 4 joints appear to use no gasket/collar.

Oddly my modern bike doesn't seem to wet the floor but it has an upswept exhaust and fuel injection, cat etc. No joints or holes in the lower pipes though !

[Johnwebley]

on my 500,all 4 pipes have drain holes,in colder weather they puff steam from them,and the tail pipes,

 because of the expense of replacing them,I try never to do short journeys,and always find an open road to get the motor
a blast,normally to over 8k rpm in 3rd,hoping the heat will dry the insides,

[Nurse Julie]

on my 500,all 4 pipes have drain holes,in colder weather they puff steam from them,and the tail pipes,

 because of the expense of replacing them,I try never to do short journeys,and always find an open road to get the motor
a blast,normally to over 8k rpm in 3rd,hoping the heat will dry the insides,

Yes John, that is exactly what I have just done. I'm now assuming the condensation forms when I start the bike up and that by the time I have had a good ride, the water has all been blown out and then the exhaust is dry until I start her up again. It was marginally better today so hopefully it won't be much longer before she stops peeing herself