Hyosung GT650 Comet. Oil in the airbox?

**Monkeynz** · 5th March 2012, 20:54

I have started to race a GT650 Comet and have found a lot of Oil coming out of the overflow pipe that has been connected to a small box attached to the airbox. When I took the airbox off I noticed a huge amount of oil sitting in the bottom. I see that the crankcase breather hose runs up to the airbox and there are a couple of other tubes that run down to a couple of pumps? (not sure what the hell they are).
It seems to chuck out a heap of oil, any ideas?

**nzspokes** · 5th March 2012, 21:03

Make a proper oil catch can and breather. Probably high revs is over pressurizing what the stock system can handle.

Either that or your rings are stuffed.

**DrunkenMistake** · 5th March 2012, 21:31

Drain the oil...
I have a sneaky feeling you may have over filled the poor beasty.. Korider.com is the Hyosung forum, they may have some ideas, but be warned they are slow to reply, just like the bikes.

Are they two little pumps on either side of the frame? connected to the front cylinder and the other to the back? those are the air injection system,
You can disconnect them and put block off plates where the connect to the cylinders its Hyos pear valve.
Removes a little weight, and im sure it has some miniature gain in something.

**ducatilover** · 5th March 2012, 22:44

It'll be throwing oil up off the gears

I wouldn't get worried about it, my bike does it and it's a real bike

**DrunkenMistake** · 6th March 2012, 11:07

Originally Posted by ducatilover

It'll be throwing oil up off the gears

I wouldn't get worried about it, my bike does it and it' s was a real bike

fixed that for you

**Monkeynz** · 10th March 2012, 19:34

Originally Posted by DrunkenMistake

Drain the oil...
I have a sneaky feeling you may have over filled the poor beasty.. Korider.com is the Hyosung forum, they may have some ideas, but be warned they are slow to reply, just like the bikes.

Are they two little pumps on either side of the frame? connected to the front cylinder and the other to the back? those are the air injection system,
You can disconnect them and put block off plates where the connect to the cylinders its Hyos pear valve.
Removes a little weight, and im sure it has some miniature gain in something.

Nope definitely not, checked before I rode it and it was more on the low side. I did wonder what those thingys were on the each side. Might do some more research on those things then and see how important they are.

**Monkeynz** · 10th March 2012, 19:37

Originally Posted by ducatilover

It'll be throwing oil up off the gears

I wouldn't get worried about it, my bike does it and it's a real bike

Shit, that's a heap of oil getting chucked up into the system. Must be something else, I lost about half a litre in a couple of races.

I'm not worried....

**ducatilover** · 11th March 2012, 13:00

Originally Posted by Monkeynz

Shit, that's a heap of oil getting chucked up into the system. Must be something else, I lost about half a litre in a couple of races.

I'm not worried....

That's a pretty good effort!

**DrunkenMistake** · 11th March 2012, 15:38

Originally Posted by Monkeynz

Nope definitely not, checked before I rode it and it was more on the low side. I did wonder what those thingys were on the each side. Might do some more research on those things then and see how important they are.

Not at all important, I cant remember the technical jargon but basicly, when they do emission tests they do it at the end of the exhaust, the AIS (air injection system) shoots air into something or somewhere, causing it to 'dilute' the emissions. like adding water to syrup sort of thing, put a race can on the bike and button off the gas and it will go POP, thats the AIS.

**FROSTY:Me** · 26th March 2012, 16:09

monkeynz for racing I don't recommend having any kind of oil breather running back into the airbox. I know in some cases as long as the box is sealed up its concidered to be a catchcan but in this case even if hyo 650's do drink a bit of oil in race conditions having oil and oil mist floating around the engines air supply isn't going to do performance a lot of good.
I'm also reminded of an old xj900 I used to have. same symptoms as yours.The bike would continue to blow oil up the crank breather into the airbox as long as there was already oil in there. Wash it out. clean out the pipe and it stopped pumping

**killapotatoe** · 27th March 2012, 22:11

Over flowed with oil?
Rings are on the way out?
Piston was replaced and honed out with to much gap. because didnt go over sized?
Hose pushed onto wrong place?
Electronic valve not working?
Dirty /blocked air filter / trying to suck through breather hose? Change air filter or use k&n recharge kit

My idea's

**DrunkenMistake** · 27th March 2012, 23:00

Well I had a similar issue, on the left hand side (sitting on the bike) I had oil coming out,
Turned out the crank case breather hose's connect to a small oil mist catcher below the air box, one of the hoses were disconnected, so after my oil change when I put a few 100ml too much in, it backed the oil up into the mist catcher but instead it filled from one hose and pissed out of the open hose.
Could be worth checking the mist catcher, if its not empty or cleaned out it can keep happening.

**Haggis2** · 28th March 2012, 11:10

Thats normal - its to stop the airbox rusting

**DrunkenMistake** · 28th March 2012, 11:19

Originally Posted by Haggis2

Thats normal - its to stop the airbox rusting

I see what you did there

**Monkeynz** · 29th March 2012, 18:29

Thanks guys some good info there, I have done nothing on the bike as there hasn't been any racing going on down here and have had other things that have needed attention.
Will investigate further. I wonder if there is some sort of system I could attach to the crankcase breather that would still allow the crankcase to breath but let the oil drain back into it?