Jump to content

Radders

Spark plug cap

Recommended Posts

Hi, after some advice please, had my 4rt out the last weekend and it wouldn't start, went to take the plug out and the ht lead came straight out of the cap, I managed to bear some of the rubber back and ram it in the cap then sellotape, yes sellotape, it in...I managed three hours solid riding without it missing a beat, now can I just get a new cap or do I need to get one with a ht lead connected to it since bearing the wires back slightly?

Share this post


Link to post
Share on other sites

Typically the replacement caps have a threaded point that screws onto the lead into the center core where the conductor is. Nothing too complex unless Honda has some special weirdness I don’t know about.

Share this post


Link to post
Share on other sites

Last time I replaced a lead cap it was just a screw on job...

I would check the cap you have now and see if it is a screw on type.  If so and you have enough extra length on the current lead you should be able to just cut the lead end flat and screw the cap straight on.

  • Like 1

Share this post


Link to post
Share on other sites

I would recommend that you pull the old cap back off and check it with a multimeter to make sure it’s not a resistor cap as well 👍

If the HT lead is long enough, you may be able to cut it back 1/4” and screw your cap back on to it. Worth a shot :)

Share this post


Link to post
Share on other sites
1 hour ago, jackman290 said:

I would recommend that you pull the old cap back off and check it with a multimeter to make sure it’s not a resistor cap as well 👍

Right, whats a resistor cap and whats it do mate?

Share this post


Link to post
Share on other sites
18 minutes ago, section swept said:

Stops your ignition signal from ruining Coronation Street.😜

Coronation street? Is that part of the cylinder head? 😉

Share this post


Link to post
Share on other sites

Heh heh British television.

The cap has a resistor in it that limits the rise time of the spark current. That reduces the radio frequency electromagnetic waves emitted by the wire. So yeah, the BBC thanks you.

Share this post


Link to post
Share on other sites
7 hours ago, dan williams said:

Heh heh British television.

The cap has a resistor in it that limits the rise time of the spark current. That reduces the radio frequency electromagnetic waves emitted by the wire. So yeah, the BBC thanks you.

So what you're saying is i might not have to pay my tv licence if I'm doing them a favour by not interfering with the reception 😉 

Share this post


Link to post
Share on other sites
On 29/04/2018 at 3:02 AM, dan williams said:

No they’ll charge you a convenience charge for not interfering. That’s how a  bureaucracy works.

Yep and with the money they’ll produce even more dire crap!

Share this post


Link to post
Share on other sites

It is my understanding that the resistance in the circuit will give longer spark dwell time and also protects the CDI from harmonics getting into the module, which could wreak havoc on the engine timing.

I’m not saying it will not run with zero resistance, but it could be a gamble with expensive electronics. This is confirmed by Steve at motoplat 👍 Just wanted to spread the word

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×