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Engine shuts off opening throttle (after wash)

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by dima, Jul 2, 2012.

  1. Hi,

    Yesterday washed the bike and let it dry in garage overnight.

    Today in the morning, started it and everything seemed to be fine.

    While it was warming up I did a quick pre-ride check, put my helmet/gloves on then jumped on the bike.

    Opened the throttle a little bit (still in neutral) and the engine shut down.

    Then I couldn't start it a few times... But when I opened the throttle and tried again, everything came back to normal, weirdly enough.

    So what has happened?
    Did I flood injectors, air filter, something else?

    Should I be worried about it (it hasn't happened before)?

    (couple of months old CBR250R).

  2. Pressure washer or hose?
    EFI or carbys?
  3. EFI, washed in a garage with a hose & bucket of water.

    The only thing that gets to mind is that this time I used the washing liquid with wax instead of a regular one.
  4. Nah, if soapy water is getting in while you're sponging it on, you got much bigger problems...
    And I just noticed you mentioned injectors - sorry for the silly question ;)

    The only problem I have is setting the alarm off when hosing the rear under-guard, if I don't disable it first. I don't go poking the hose up under the tank however - the injectors and spark units are under there for good reason!

    Only thing I can think would be wetting the air filter, but others may have different ideas to consider.
    Wouldn't hurt, and costs nothing to check it anyway.
  5. So using wax-y liquid is fine? I was a bit concerned about the chain, but I though I'd clean it thoroughly anyway after the wash.

    Thanks, I think I'll do it today when I'll get back home.
    Will have to read a bit about it though - would be my first time :)

    Can it be water in fuel or something?

    But I don't exactly understand why the engine shut off and then couldn't start without open throttle...

    My guess (assuming it's an air filter) is:

    1. when I opened the throttle, there wasn't enough air, but too much fuel, so the engine shut off
    2. when I tried to start it, the engine was full of fuel but too little air;
    3. when I opened the throttle, it gave a bit more air which compensated the amount of fuel in the engine

    But not sure if that is the correct thinking...
  6. did you stuff a rag in a vent when you washed it?
  7. Perhaps some residual water evaporated as the engine warmed and then condensed again on a cold surface such as a coil pack and caused the sparks to run to ground through the water. Then as you tried to figure out what was wrong it too evaporated as the engine warmth spread and allowed it to start again? The opening the throttle thing might have been coincidental.
  8. Definitely not.

    Maybe, but I really don't believe in such kind of coincidence :)

    Being curious what the hell was going on...
    After I started the engine and kept it running for a while I decided to shut it off myself and try to start again (yeah, I knew that I just needed to give it a bit of air).

    Strangely enough, I didn't even need to open the throttle. It started as nothing happened.

    Perhaps my bike gets some mood? :)
  9. I'd say you got water down a plug recess. It earthed under load and cleared after evaporation.
    • Like Like x 1
  10. Ok. So far reasons may be:

    • flooded ait filter
    • residual water (probably somewhere around coil pack)
    • water down a plug recess
    • vapor lock (as some of the guys described here).

    But generally it seems that I shouldn't worry about it too much. Right?

    Things I should do:

    • check the air filter
    • check the spark plugs
    • check the correct fuel is used (being using Shell's premium unleaded 95)

  11. just keep an eye out where you splash water next time. Some bikes are worse than others.
  12. Running ok at idle and dying upon opening the throttle sounds a lot like lack of fuel. I'd be checking fuel pump.
  13. shell fuel :-(((
  14. my bet was that when you started it was a cold morining and you did not let the bike warm up enought my bike does the same
  15. Thanks to all of you guys.

    Fuel may be it.

    I tried BP 98 last Saturday and the bike felt great.
    Then filled in with Shell 91 just to try (usually use 95). There you go, got the same thing once in the cold morning.
    And the bike felt so underpowered (even though it is already low power 250cc).

    So I'll probably try to switch to BP 98 and see how it goes + plus give it a bit more time to warm up before touching the throttle :)

    Used shell just because my wife gives me discount from coles on it.

    Feels like shell is noticeably worse that BP for my bike.
  16. In Victoria there are only two refineries, the Shell one in Geelong and the Mobil one at Altona. All our petrol comes from them (not sure if anyone imports it now that the supermarkets have aligned with Caltex and Shell). All the tankers fill up at those two refineries.
  17. 98 might not give you any benefit over 95 (I go for Caltex/Ampol/Mobil).

    I avoid 91 because it is generally crap, with or without ethanol.

    You might have just had some soluble crap or water in the fuel or you just wet one of the sensors or other electrical connections you find in a modern EFI bike.
  18. I have had similar problems with my fuel injected bike.
    Naturally it's intermittent and the bike shop can't replicate it to diagnose it, but there is another theory they came up with.

    Does your bike have a cut-out switch on the sidestand? Clutch?
    Mien has such that it cant be started with the sidestand down (unless in neutral) or if the clutch isn't held in.

    If water gets into these switches it could theoretically lead to the engine cutting in and out as the water sloshes around on the contacts in the switch.

    Just worth consideration.
  19. mmm
    i would start by removing airfilter and make sure everything is ok there,
    air filter is most likely and simple to check and eliminate so thats the best start.