Oil Leak smells of petrol

[PaulHarding]

Hi
Just bought a 1966 Arrow, 200cc with 36000 on the clock, which I understand has been used on and off over the years.
Started and ran it for a short while yesterday. Went into the garage next morning and there was a little trail of oil underneath the right side crankcase.
Cleaned it up and started the engine for a couple of minutes, again a few drops of oil dropped from the crankcase. The oil was black and smelt of petrol.
The previous owner said it was to do with the unburnt Petroil settling in the crankcase.
As a newby to this 2T world, appreciate guidance on this.

[nevhunter]

That's what it will Be. Nev

[Simon.Gardiner]

It'll be petroil pooling in the sump. My arrow can also bleed what always seems to be copious amounts of oil from the exhaust pipe joints.
Be aware that these engines don't have a sump drain - too much carb flooding will lead to petroil sitting in the crankcases and it can take a while to burn it off.

(And with admin hat on, moved to 2-stroke.)

SG

[ian williams]

hi paul , they all do that to some degree , youll get streaks on the exhaust downpipes and often oil drips from the pipes on to the floor , youll probably get some oil drips from the primary chaincase too and if the oiler for the rear chain is actually functioning you might get drips from the rear chain case too .
in the back of the crankcase there is a gallery that passes between the primary chain case and the rear chain case which is supposed to have a bit of felt in it and then a small amount of oil can make its way from the primary chain case and into/onto the rear chain .
i think often the felt is either old and blocked , or it has been removed when a rebuild takes place and is not replaced , but it is supposed to be in there to control the "flow" of oil to the chaincase .
i dont know if the chain oiler idea works very well though but i do know my NH has a similar thing with a screw you can adjust to set the oil flow rate to the chain .
if mines wide open though i get oil all over the rear wheel lol.

i think you need to run the 2 strokes and get them hot , and also run the fuel out of the float bowl before you stop the engine when you come to park them up in the garage , then you wont have a problem with oil mix settling in the crankcase .

[PaulHarding]

Thanks for your replies, very useful to a 2 stroke newbie

[Ivor Collins]

Take a close look at the exhaust down pipes. If there is any sign of oil streaks emanating from the joint with the cylinder, it will just be the unburnt 2/ oil.
The simple remedy is to remake the joint using a high temperature RTV.