Hyosung GT650 Comet. Oil in the airbox?

[Monkeynz]

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]

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]

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]

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 :bleh:

[DrunkenMistake]

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 :bleh:

fixed that for you

[Monkeynz]

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]

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 :bleh:

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. :doctor:

I'm not worried.... :baby:

[ducatilover]

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. :doctor:

I'm not worried.... :baby:
That's a pretty good effort! :blink:

[DrunkenMistake]

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]

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]

Over flowed with oil (http://nzairfilter.co.nz/powersport-oil-filter/)?
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 (http://nzairfilter.co.nz/motorcycle/du-1006.html) / trying to suck through breather hose (http://nzairfilter.co.nz/breather-filter/)? Change air filter (http://nzairfilter.co.nz/motorcycle-air-filter/) or use k&n recharge kit (http://nzairfilter.co.nz/cleaning-kits/99-5050.html)

My idea's :shutup:

[DrunkenMistake]

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]

Thats normal - its to stop the airbox rusting :bye:

[DrunkenMistake]

Thats normal - its to stop the airbox rusting :bye:



:laugh::laugh: I see what you did there

[Monkeynz]

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?:bash:

[mellowyellow]

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?:bash:
i asume your being funny, but incase your not, build an oil catch can. you can either have it drain back into the crankcase or vent into the atmosphere, or both.
to be honest, i'd rip the air injectors out, chuck in an oil catch can vented out into the atmosphere and drain it after each race/meet.
keep in mind i first sat on a bike last friday, but bike engines work like cage engines, air/fuel/compression. any cage engine pumping oil into the intake usually means to much crankcase pressure. throwing in a good oil catch can prove to be a good band aid that works well.

heres why i think a oil catch can is all you need.
under normal load and revs, the compression ring blow by is able to be countered by crankcase breathers and baffles.
ramp up the load and revs and you are increasing the compression ring blow by and the occurance of the blow by. so now the crankcase breathers and baffles cant handle venting it all at the designed pressure, causing oil mist to be sent out the breathers and filling the baffles.
basically, you have too much crankcase pressure, you need to filter it and vent it more efficiently i.e oil catch can :yawn:

[Monkeynz]

I have finally solved the problem. :banana:The engine has had work done on it before I bought it and they didn't connect the breather pipes to the correct outlets/inlets on the airbox. It took a lot of research on the internet to work it out. :brick: But finally found some pictures that showed me where the pipes are meant to go, no wonder I was having problems with oil filling the airbox. :oi-grr:
While I was at it I removed the AIS system which I also found out about while I was doing my research.
And I have ordered a jetting kit.;)