Exhausts and Oil

Crestfallen · Borekit Bruiser Joined: 21 May 2002 Karma :

Hi All
I've noticed that my exhaust has oil coming out of the end over the past few days. The bike is a Aprilia RS125 and is only like 9 days old. The oil started off a brown colour but is now black (due to the exhaust carbons polluting it?)
I first noticed this when my bike was parked and i saw a small drop on the ground below where the end of the exhaust is. Is this normal for 2 strokes?
I know that they aren't very efficient at burning the 2 stroke oil properly and part of the exhaust fumes are unburnt oil along with the proper petrol fumes.

Regards

Doddmaster · World Chat Champion Joined: 02 Feb 2002 Karma :

Dunno if its bad or not, but it happens on my nextdoor neighbour's RS too! (it is 5 days old)

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

this is only my reasoning and keith will probably prove it wrong, but with a brand new, ie not run in engine, the piston is much tighter fit in the barrel, so the oil cannot coat the barrel, it just gets scratched off by the piston and only some of it is combusted, leaving the rest of it to leave the engine with the exhaust gases.
also the oil is often turned up on bikes that are running in new engines to ensure it all goes smoothly, so the combination of these two should mean you get some pissing out the back.
as for it turning black that will just be the coke in the exhaust mixing with it.
you start getting worried when lots of petrol come out the back of your exhaust, my 50 did that when i left the tap on.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Fairly normal. 2 strokes dont manage to burn all the oil (or petrol), and you would be in deep trouble if the piston scraped all the oil off the bore

All the best

Keith

batman · Scooby Slapper Joined: 06 Feb 2002 Karma :

ive had my rs since october and the oil will never go!
theres a filthy black mark on the cobble stone at my door from it and my cover is buried in oil-it will stay, the rs seems to piss out a lot more of its unburned oil and petrol than the nsr

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

I suppose it is worth noting that the RS exhaust is meant to be sealed to the engine using a high temperature silicone sealant, which is meant to stay soft. Never managed to find any to use, but that would stop the leak from the engine / exhaust joint

All the best

Keith