Hi all. First post.I'm actually posting this for a friend. The bike is a 2002 F4i and it keeps popping the spark plug wire off its base.

-Friend keeps putting the wire back on but it keeps popping out again. Friend says that it happened during a slow acceleration from 1st gear where the engine made a popping sound and then ran rough which makes sense as it was firing on one less cylinder. Upon trying to put the plug wire back in as best as they could, it still keeps shooting off at startup.

-Could this be a telltale sign that there's a more serious problem with some pressure leakage causing the plug wire to come off like that?

Friend is actually roadside right nowwithout any tools to get the fairing off so it's going to be towed. In the meantime, I wanted to see if anyone has had any experience with this or knows of potential problems.

Thanks in advance!

 

What exactly popping off, the ignition coil pack or the electrical connector going to the coil? F4i's don't actually have spark plug wires since it's coil-on-plug ignition. If it's the coil popping out, is it blowing the spark plug out with it?? If not, he may want to pull the plug out and make sure it has the sealing washer on it and that it's properly torqued down. If it's blowing the plug out though... he's got problems. Helicoil time!

 

Thanks for the quick response! Actually not sure which item (the ignition coil pack or the electrical connector going to the coil) it is but I assume it's the one connected nearest to the cylinder because my friend says the pressure is popping it off. Kinda hard for me to say since I'm not actually looking at it but hope that helps a bit. I'll try and find out more though.

 

that would be the coil pack...he's got a leak coming from around the plugs.

 

...And would this leak be the sealing washer?

I've had this issue when I changed to higher octane fuel. The far-right cylinder's coil would loosen a bit and pop up like OP described. Weird sound.

 

Hey all, thanks for the responses. Just wanted to update the thread.

So the bike was taken to a honda mechanic and they found that the spark plug had actually backed itself out for one reason or another. No idea why. Fortunately there's no damage to the thread, cylinderor the plug itself but new plugs are being installed as I type this out. Our concern was the thread might've been stripped or worse, something had gotten into the cylinder and scored it. Fortunately not the case.

BTW, for all who said it was the coil pack, it must've been because everytime my friend kept pushing it down, it would pop the entire thingback out. It makes sense now because of the plug being backed out. I don't know how far out the plug was but I did hear it popping wildly over the phone. Maybe just enough to let some pressure out? Either way, situation being resolved. Cheers