Jump to content

Spark plug lead replacement


vfr200

Recommended Posts

I got caught in torrential rain on the motorway the other day on my 1999 VFR. One or more cylinders must have stopped firing properly because it felt like someone had attached a heavy trailer to the back of the bike, i.e. it took what felt like twice as much throttle to maintain my speed. It was also running seriously rough and every once in a while the power would kick in again for a brief moment.

 

While this was happening I noticed that the engine temperature reading dropped from 78 degrees to about 70. Given that the temperature sensor lives behind the front cylinders I'm guessing that it was one or both of them which had stopped working.

 

Shortly after the rain stopped the bike went back to normal as though nothing had happened. I rode through another spot of slightly less heavy rain later and the problem briefly came back.

 

I'm assuming that the problem is HT lead-related given the symptoms and the fact that they're 24 years old and live sandwiched between a hot engine and road spray, but I'm reluctant to pay £150-odd to replace the front two leads and plug caps with new OEM stuff. My current thinking is to get a used set off eBay for next to nothing, check the caps for cracks and replace the cables with generic new leads. I've had a search but can't find any threads on here about it; has anyone else done this before and could you give me any pointers?

Link to comment
Share on other sites

  • Member Contributer

H2O could have gotten into the fuel tank also. It doesn't take much. 

Link to comment
Share on other sites

  • Member Contributer

I've driven through similar and never had these symptoms, my bike is a 98. All on that side is original.

Did you look at your injectors as per your other post? It was you wasn't it? If not my apologies 😇

Link to comment
Share on other sites

1 hour ago, Bren said:

I've driven through similar and never had these symptoms, my bike is a 98. All on that side is original.

Did you look at your injectors as per your other post? It was you wasn't it? If not my apologies 😇

 

So have I and never had problems until just now. The fact that it happens fairly abruptly when the going gets soaking wet and stops as soon as it dries up screams electrical to me, and the front HT leads are the obvious suspect since a) they're the only electrical wires that routinely get drenched and b) I'm pretty sure a short elsewhere in the ignition would kill the bike stone dead instead of just making it drop a cylinder or two.

 

Don't think the post about injectors was me; I haven't posted here for a couple of years and I can't remember what that was about!

 

2 hours ago, bmart said:

H2O could have gotten into the fuel tank also. It doesn't take much. 

 

If that were the case I doubt it would clear up within a few minutes of the rain stopping.

Link to comment
Share on other sites

  • Member Contributer

Never happened before...isn't that how all things happen? 

Link to comment
Share on other sites

  • Member Contributer
19 minutes ago, bmart said:

Never happened before...isn't that how all things happen? 

 

Yep.  Just like you always find something in the last place you look.

Link to comment
Share on other sites

  • Member Contributer

Just wondering if the HT lead unscrews from the plug cap? 

Perhaps a local reputable Auto Parts store may be able to help you out and make up some leads for you. Take the two originals along with you, see what they say. Just a thought!

Link to comment
Share on other sites

  • Member Contributer

I had this happen once riding in torrential rain as well on my '98. It would intermittently bog and then run okay again for a bit, then bog down again.  I took everything apart, and found some water had gotten into my airbox.  Replaced my air filter and it hasn't run rough since in rainstorms or dry weather.

It might still be your HT leads, but that was just my experience.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.