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Wet Hornet = bad running

Discussion in 'Technical and Troubleshooting Torque' started by mattb, Mar 9, 2010.

  1. G'day All.

    I'm having a problem with my '98 Hornet 600 when riding in those absolutely soaking showers. Normal rain is fine, I'm talking about those odd showers that utterly enter and soak every cranny and crevice. So, two times now this problem has occured.

    -The bike seems to run with maybe only three cylinders firing (I4) at it's worst. Otherwise it just runs like it's starving (not saying it is - but it's that sort of behaviour). Jerky running also.

    -This is all at slow speeds: idle and up to 40 or 50kph, stop-start city commuting. I've been in similar storms on sustained rides down the Calder and Hume and it hasn't happened. And when I got a chance to open up to 60kph sustained, it was ok also.

    -One of two times, the rear indicator also wouldn't flash, then came right when things dried out.

    -The problem goes when things dry out.

    -The exhaust blows a lot of white smoke - constantly - in these scenarios, and smells of fuel.

    Diagnosis: I'd assume it's gotta be water getting on the electrics, in under the tank. I'm wondering if maybe a coil is getting wet. Or somewhere between there and the sparkplug. I'm guessing that the water that enters in a lighter downpour isn't enough to soak into the problematic places. (But why is it fine at greater speed, bad at slow speed?)

    The Hornet runs pretty lean normally, I hear, and certainly it's unsmooth when cold, so maybe this is contributing to the problem....(we're talking 5 minute commutes where the issue has occured).

    I guess I'll just have to pull the tank off and check for exposed wire / places where water can seep in. I've got a stone fairing I'll get next time I'm up home: fitting that might stop the water from entering or at least drenching the area. Or maybe I can make some sort of rain-guard at the head stock in the meantime (a kind of bad mofo motorcycle shower cap).

    Any thoughts on this?


  2. Matt, I rode between just north of Cooma to almost Goulburn yesterday in rain of almost Biblical scale and mine never missed a beat. I suspect that you have a crack in the air-intake side of things, and that the water being dragged in is causing a plug to drown, and also the white smoke. Just guessing, though ......
  3. Lashings of silicone grease on all electrical and HT lead connections, condoms on the coils and maybe a mudflap on the front mudguard will see you right. You could be cheap and use vaseline, but it melts and makes a mess of your engine and needs renewing every few weeks.

    It could also be that your HT leads are not in the first flush of youth.
  4. Agree with Hornet about the drowned plug - if it's coming out the exhaust as white smoke (steam, along with unburnt fuel) then it's water definitely going through the combustion chamber, so the question is where is it getting in? Airbox seems likely, especially as it is only happening in deluge conditions (WTF are you doing out in that anyway?). Maybe your air filter is just getting totally soaked? Alternatively, is the fuel tank seal good?
    Indicator issue seems like a separate matter IMO. You might as well check the wiring but I doubt that's it.
  5. +3 on water in the plug recess. Check if there are drainage holes and blow them out.

    Also check for cracked leads and plug caps.

    Indicator coincidental.

    Probably a regulator on the way out (joking).
  6. Yup. First gen SV650's run only on the rear cyl in really bad rain, the front cylinder is evidently angled perfectly to collect water :) I got the silicone grease out and never had any issues. This was fixed on the later models with a plastic flap.. go suzuki ingenuity lol..
  7. I had the same thing on the TRX when I didn't seal the spark plug rubber back up properly, check em out seem if their not seated correctly or cracked.

    That's where I'd start,
  8. spot-on from Patb, too on the mudflap on the front guard. I have a Fenda-Extenda on my front guard; that may have made the difference I spoke of earlier. The Hornet front guard is almost decoration, rather than function.....
  9. I can't provide any additional thoughts or help but I do feel compelled to say that the above posts are a prime example of why I joined Netrider the collective wisdom, experience and knowledge is priceless.
    Sorry :oops: please carry on as if I wasn't here.
  10. Yeah, we are awesome. Modest too. :D
  11. Thanks guys. I'm changing the spark plugs in the next week or so - will use the chance to inspect everything and, whether or not I find what looks to be the problem, I'll also get the silicone grease into action. I'm intending to get some rubber and extend that fender anyway, as I don't dig the dirty water covering the pipes all the time. I guess if an inspection and greasing shows nothing but the issue continues, I'll try to get at the air filter while things are playing up and have a look. I reckon the stone fairing will help also, as well as looking bitchin'!

    Will replace the HT leads anyway when I get some spondooli aside to do a few similar things (like replacing all the hoses).