Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

ZZR250 - Strong Petrol Smell

Discussion in 'Technical and Troubleshooting Torque' started by MitchnZara, Oct 5, 2013.

  1. Greetings,

    As title suggests I have a strong smell of petrol in the garage after the bike has been sitting for a while (a few hours / overnight).

    I have noticed that I get a small amount of fuel coming up through the lock barrel on the fuel tank cap. Which I guess could be normal as it is a place for the tank to breath / vent? (Maybe? Maybe not?)

    Today, however, I was going for a ride and happened to look down whilst stopped at lights. There was quite a bit of fuel around the flap hinge on the fuel cap - I had been going over a few nasty bumps so I wouldn't be surprised if it was just from the fuel splashing around and trying to get out through the top.

    Lastly - She (Her name is Zara) has been a bit hard to start for the past week-ish. Will just sit there with the starter trying to kick it over but it just won't go. At first I thought this was due to a bit too much oil - I changed the oil and filter and only added 1.6L of oil (Manual says 1.9L if filter changed) and I was already over the full mark in the sight glass. So, I drained a bit out after a couple of days but the problem remains.

    So, Are there seals in the fuel tank cap that need special replacing that I can't see? Or, is this a carbie issue where they're just so dirty that they are actually venting fuel to the atmosophere and causing the crap starts?
  2. I think you may have summed it up in one mate, Id be taking the carby/carbies apart,good clean and new gaskets,then follow lines back to tank and change anything that looks suspect.
  3. Sounds like the tank vent is blocked. It should be a small hose under the tank somewhere that's NOT connected to the fuel tap. I'd expect to see it near the back underneath.

    Alternatively, check the cap seal on the tank. Might be perished.

    Other vents are from the carbies through a hose down under the bike. I think it would be on a t-piece between the carbies. It might be time to give the carbies a good clean and treat her to a new set of plugs.
    • Like Like x 1
  4. Yeah, was thinking it was going to be the carbies. Can anyone throw out a rough price range that they or people they know have paid in the past?

    I'm going to get as many qutoes as I can but a ball park figure that people have had always helps :)

    In the interim does anyone suggest use of those fuel additives for carb cleaning? I know it's not going to fix it but if it makes it slightly better leading up to a full clean then it'll be worth it.
  5. no idea mate, however if you ring a carby o/haul shop they will recommend what additive they thinks is best, failing that, the local speed shop,although with them Id specify what you want the additive to do. Email local dealers and ask for a P&A on carby replacements, in new or change over as too much info isnt a bad thing.
  6. About $15 for a can of carby cleaner and some time. It's not hard to do yourself. Tank off, seat off, side covers off, undo clamps on carby ends, unbolt airbox and move it backwards in the frame. Pay attention where everything came from. Just DO NOT disturb the balance screw between the two carbs if you're set up to re-balance them. The balance is critical to those engines.

    Replacing the carbies is going to cost stupid money for a ZZR250 and is most likely completely unnecessary.
    • Like Like x 1
  7. It doesn't sound right that fuel is welling up through the fuel cap.
    I would check that out first. This is also likely the easiest to check and cheapest.
    If you're going to strip the carbies, check the float needle valve hasn't got a ring worn it it.
  8. As for fuel coming up out of the cap ... you know to stop filling at the bottom of the filler neck and not go right to the top, yes?
  9. IIRC, ZZR250's vent the tank through the key hole (the key hole goes all the way through), and there's another airlock vent that gets plugged when you close the cap. Are you over-filling, then parking somewhere warm, where the tank heats up, and the fuel expands out the key hole? OTOH, because of the key hole going all the way through, vapour will escape, making the bike stink. My old ZZR stank, but I just assumed it was just the way they were.

    When mine didn't want to start, I cleaned the sparkplugs with a spray of carby cleaner, let them dry, put them back in, then it would start first attempt.

    Good luck!
  10. Hey Guys, Just an update - I will be pulling apart the carby myself. God help me... Nah, watched a youtube clip (All praise the mighty YouTube) and it took the fear out of me. I'm relatively mecahnically minded but have never pulled a major component apart like this before but the clip made it look very straight forward.

    As for the full coming up through the lock barrel. It happens regardless of how much fuiel is in the tank. I don't go past the filler neck when I fill too. I've checked the tank breather hose and it is clear of obstructions and not kinked or crushed. I think it might just be that the lock barrel is a second breather hole and shouldn't cause too much worry.

    Will pull the carbs apart and clean over the next two days. Will advise how I go with it all.
  11. Just another quick update. Have pulled the carbies out. Have only looked at one so far - being the left one which should be the dirtiest if side stand is always used... But anyways, it's very clean, only a small amount of rust in the float bowl and the jets look good. Even the side holes on the jets are clear. Yay for me. But I have found what I'm thinking is the problem. The gaskets are pretty much non existent as in. It's not solid all the way round, has no height to it etc etc.

    Could this be the cause of my dramas or is there another root problem? Also, replacement gaskets or gasket maker? I'm thinking gasket maker. There's some good permatex ones.

    Also, there was a short rubber hose that was just loose between the carbs and the frame. Looks like the fat end of hose could attach to front of air cleaner box but I don't know what the other end is meant to be connected with... Anybody? I've got a pic but I can't find the option to upload to this thread. The hose is 10cm long and has a right angle at one end and the other is a 180 degree turn. Anybody?
  12. Have to see it in context to be sure, but it sounds like the carby breather hose. Be careful not to disturb that adjuster screw between the carbs.

    The "Upload a File" button is between the "Post Reply" and "More Options" buttons below the bottom right hand corner of reply text box.
  13. Can you point it out on the diagrams below. You may not have enough posts to upload images yet.

    ZZR250Fuel1. ZZR250Fuel2. ZZR250Fuel3.
  14. Ahhh... there's a post count before I can post images. Makes sense now why I couldn't see the option to upload.

    The hose in question is the item in the bottom right corner of the last image Looks a bit like a question mark. By the diagram it looks like it's meant to be INSIDE the airbox? If so, how did it end up outside? Eeeep.
  15. Nope, not inside. It connects to a spigot on the right side of the airbox. I'd say that's the drain line. Better if it's in place but not going to cause real damage if off for a little while.
  16. Beautiful, thanks for that.
  17. Well I've just been searching all about gasket makers. And the best they can do is say that they are 'gasoline resistant'. Not sounding too crash hot considering this is my fuel system here. Time to get me some real gaskets... Which means she'll be off the road even longer :banghead:
  18. Which gasket are you talking about?

    Carbie gaskets usually come in gasket kits. Finding one for a 250 might be difficult as most emanate out of the US.

    So you are stuck with OEM.

    Also, from your description above, the carbies would not have been the first place I would have looked. So don't be suprised if this carbie activity doesn't solve the problem (or at least not all of it).
  19. I'm after the float bowl gaskets. I've found some in America, the UK and Germany. Cheapest is Germany for $24 for the two incl shipping. Stuff from the states has ridiculous shipping prices :(

    What would be your suggestion as to what to test out ibast?
  20. German price seems reasonable. Better get used to bike part prices.

    I've seen over $120 quoted for carbie kits, per carbie. That does include all o-rings, gaskets and usually a float neadle. $24 for 2 gaskets delivered isn't bad however.

    Reading you OP again, it may be just the gasket. See how it goes.