Front spark plug drain hole

Someone on Orkut’s SV community posted yesterday, inquiring about the front spark plug drain hole. It prompted me to finally go take a picture of the one on my bike, as this hole is a well-kept secret that can save a lot of headaches.

If you own an SV(S), go out and find this drain hole. It’s a small hole about halfway down the righthand side of the front cylinder.

This drain hole ostensibly drains the front sparkplug well. Unfortunately, the SVs’ front sparkplug seals have a tendency to leak water in heavy rain, which means that dirt and grime can get down into the well and clog up the drain hole. Water then pools up in the sparkplug well, eventually “drowning” the sparkplug and causing misfires (or a complete lack of firing) in the front cylinder.

So: if your SV ever acts like total shit in the rain (or just after a washing/rainstorm), pull off the front sparkplug boot and re-seal it. Then, shove a pipe cleaner up that drain hole and clear it out. Nine times out of ten, this will solve your wacky engine behavior.

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9 Responses to Front spark plug drain hole

  1. Alex says:

    Since I tried to see if my truck can float, the only running vehicle I have is my bike. Pulling into work this morning, I felt like I was only running on ONE cylinder. (SV500S) 😉
    I’ll be out in the parking lot tonight doing just that. Thank you!
    Alex (hoping he didnt foul his plug).

  2. Andrew says:

    Thanks! Mystery solved.
    When I first got my SVS four years ago I was riding to work in a monsoon and ended up on one cylinder on a busy highway. My 650 suddenly became a 325 scooter. It made nasty hairdryer sounds as I tried to coax it the last few miles to work at something beyond walking pace.
    Until now I never knew what caused it (I just figured it was a wiring+water thing) and it never repeated itself — and I’ve been in plenty of worse monsoons since.

  3. sharad says:

    I’ve heard of people using dielectric grease on the front plug connection but don’t exactly know where they put it.
    I’m thinking that a better solution might be to just put a glob of RTV around the spark plug wire where it exits the spark plug hole. RTV should keep water and other road crud out of the hole and is easy to peel off when the front plug needs to be fiddled with.
    Of course, you should probably only do the RTV thing when you’re sure that the plug connection is good and dry; wouldn’t want to trap moisture in there!

  4. David Butt says:

    I’ve been looking for this solution for over a year now! I’ve done the WD40 spray, and dielectric grease, etc., etc. Today, now I know of the drain hole, I cleaned the grundge out, and sprayed WD40 up through the channel. Wish I’d known earlier.
    Note to self: add pipe cleaners to motorcycle repair kit!
    Also buy Owner’s Manual!
    Thanks for the photo showing the location.

  5. Peter Kaldi says:

    Oh, thanks a lot! I had this problem quite a few times, and it’s not funny when my bike switches between one and two cylinder mode in the wet corners!
    Greetings from Hungary;

  6. Brian says:

    Yes! I just bought my SV650 and ended having to ride home in the rain. When it all of a sudden started running on one cylinder I was sure I had just gotten ripped off. I ended up pulling the plugs and taking some 1500 grit sandpaper to the post, but pipecleaners are easier than cutting my hand on that damned radiator! Thanks!

  7. howard says:

    That hole that you shown. How are you actually supposed to clean it. Is the whole for the spark plug for the very front spark plug or is it for the spark plug located under the gas tank. Please if you could email me offlist.

  8. jeremie says:

    wow worked great… tough of selling my baby 🙂 but i’m gonna keep it now 😉

  9. Ian says:

    Thanks mate have been searching for this answer for weeks. Now explains why my spark plug only lasts 4 weeks in the rain. Why don’t the Suzuki mechanics that I have been too suggest cleaning the drain hole rather than saying all SV’s don’t like the wet. Was going to change bikes I was so hacked off with the problem

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