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GPX leaking lots of oil (UPDATE: thought fixed but not)

Discussion in 'Technical and Troubleshooting Torque' started by EVOSTi, Mar 3, 2007.

  1. sorry if this is long but...

    my mate brought round his GPX 250 last weekend cause it had a bad oil leak. we park it in my garage and a little bit leaks out but not heaps. so that day i take the fairings off and clean the underside of the engine with carby cleaner and started it up and let it run for a while then left it to sit. up until today no oil had leaked out so i thought maybe it had none (i couldnt see anything through the sight glass) so put about half a litre in, still couldnt see anything so put a bit more in. didnt know if it was empty or over full. started it up and let it run, no oil leaked out.
    so i took it for a run, get a couple of blocks away and pull over the side of the road and oil is GUSHING onto the road. have a quick look and its coming out of the air box on the kickstand side.
    take it home and park it on the street and there is heaps of oil running down the road from the airbox.

    anyone have any suggestions?
  2. Hey EVOSTi,

    I've got a GPX as well. I haven't got any suggestions for you but I think that I did the same thing last weekend when I did a service. I think I overfilled the oil too... well I know that I did cause I couldn't see the oil level in the glass until I leant the bike over quite a bit.

    Now during the week I noticed that there was oil under the bike and was going to investigate today. I reckon that I've got the same problem as you. :(

    I'll be interested to see what other people post in reply. Good luck... to the both of us. :wink:
  3. yes i have the same problem...although it is a brand spanking new one with only 600km on the odo. Service centre said it should be ok until i bring it in for the 1000km service. dont know why the oil would splash up to the air filter and start leaking. the oil seems to be very viscous (like sticky tar) not liquified. At the moment its not actually leaking that bad. maybe 1 drop every now and then. The mechanic said its happened to a few people as well. :shock: He also told me that the problem should be gone when i get the air filter changed. so hopefully there wont be any more of that stuff coming out.
  4. Can't really say much for bikes, but from memory this happens on the Mitsi astron engines when the rings start to wear a bit, or the PCV valve is clogged. Oil comes out of the crank case breather, and into the air intake route.

    Is the oil coming up from the carby or somewhere else? I'm sure it wouldn't be doing the carby any good that's for sure. Oil in exhaust? Check for filthy plugs, black smokey exhaust?

    I guess having overfilled the oil could cause this too.

    Hope this helps a little.
  5. The reason why the airbox is leaking oil is because if you overfill it, oil gets sucked up into the box. <--- I may be wrong on that.

    Now the most important part, how to stop it. And I had the same problem before. Basically I overfilled the bike with oil. Just put the bike on centerstand, drain the oil until it is the oil is HALFWAY up the level check window. The oil should stop leaking.

    What I would suggest is get yourselves a new oil filter, and oil. Just drain all of the current oil in the bike, and put in new one. It certainly wouldn't hurt to change the oil early :]

    Remember guys. Halfway. =D
  6. Oh by the way, try using a torch when looking at the level check. If it's empty, you will see a white thread thingy. If it's full you should see brown / dark brown oil. One sure fire way to check if it's overfilled with oil is to lean the bike quite far on the left and make a mate check it. Careful while leaning - it's heavy.
  7. Yeah, it sounds overfilled.

    Regards, Andrew.
  8. thanks for all the replies guys.

    earlier this afternoon i had another look at it once it had cooled down and decided to drain the oil just to make sure cause i had a feeling it was overfilled. anyway i put a 3 litre milk carton underneath and started to drain the oil into it, once it was nearly full i had to put the plug back in cause it was still coming out quick. checked the level and it was slightly above the top mark on the sight glass.
    so i had put approx 1 litre in earlier, the bike takes 1.9L and i had 3L in the milk carton meaning the bike must have had 4L in it when i got it plus my extra litre.
    the strange thing is my mate said it was pissing out oil but when i got it it was fine, so i guess the bike doesnt leak too bad when its got 4L in it (even tho it surely cant be good for it) but 5L causes it to get drawn into the airbox.

    so yeah, all is good now and after doing my front fork seals on my ZZR250 last week i feel quite the bike mechanic :p
  9. from memory they are about 2 litres in oil capacity, but check ya own bike manual, I am just takin a rough guess. Soooo 4 is definately overfull, 5 is friggin ridiculous, and if its that full it is gunna try sneak out ya breather which may just happen to go into ya airbox.
  10. yeah it says 1.9L on the engine case.

    another update:
    the bike seemed fine when i rode it last as previously mentioned, but after i parked it in my garage and wiped down all the oil, i let it sit from sunday till yesterday and noticed quite a bit of oil on the ground, not as bad as on the weekend but still bad. so i thought maybe its residue from earlier so gave it a good wipe down, checked the level (a bit below the full line) and left it. today when i check it, another substantial amount of oil on the ground. very hard to see where its coming from, dont think the airbox cause its pretty dry. also looked down the airbox and its not full of oil only a bit greasy.

    SO, im back to the original reason why my mate mustve overfilled it, cause it was originally leaking oil from somewhere thats why he topped it up but now i cant see where its coming from.

    any likely places?
  11. take all your fairings off.. and degrease the chasis and fairings.

    then.. regrease the chain and stick the stuff back on..

    hope that helps ?
  12. Yep, rip all the fairings off, but dont degrease it, Go looking for wet spots, you know .............. under the bike, Look carefully around pan gasket, oil filter, crankcase breather, engine side covers, find it and fix it.

  13. :LOL: :LOL: thats what i was thinking!! to put like 4/5 ltrs of oil thats what i put in my car why would you put that much in a bike?! :wink: Hope it hasnt done too much damage well it couldnt have as it had an exit point ...

    hope all is good now! :)
  14. If you got a fair bit of oil in the air box it will take a while to get it all out. The filter will act like a bit of a sponge.

    Also some bikes like 350 deg twins and singles have a check valve or similar in the breather pipe. find out whether the GPX should have one and whether yours is working properly, if it exists.
  15. Yep, it's overfilling the bike with oil that's the prob.

    The crank case breather goes into the airbox (an environmental thing because you can't be pumping excess oil into the world directly), and the motor when running is pressurising the crackcases and the oil goes the only place it can. There's a one-way valve in the circuit, so if this becomes blocked it will also stop the crackcase from breathing and produce the same result.

    It's easy to think there's no oil in the cases when in fact it's over-filled, becasue the sight glass only covers a small difference in level.

    Clean the air filter, of course, so it's just slightly damp with oil.
  16. ok heres another update: it is still coming from the airbox (i thought it wasnt anymore) i know this cause i put a piece of paper under the airbox, cause the engines so oily it was hard to see where it came from. the thing is it hasnt been started since saturday, yet everyday its leaking alot of oil.

    but like ibast said maybe the air filter has been holding alot of oil and slowly releasing it, must hold alot! ill take the air filter out and dry inside the box, then ill leave the air filter out till tomorrow to be sure theres no oil coming from anywhere else.

    thanks for all the replies guys :)