spark plug boot replacement

Got a problem. Been diagnosing my engine problems and found a badly torn spark plug boot on the right front cylinder. Must have happened with previous owner. Do I have to replace the whole coil or can I replace the wire/cap?

I believe you have to replace the whole coil. Unless somebody has figured out a way to replace just the wire, they are not designed to do so. In my opinion, that was a terrible design on Yamaha's part.

I believe you have to replace the whole coil. Unless somebody has figured out a way to replace just the wire, they are not designed to do so. In my opinion, that was a terrible design on Yamaha's part.

Is that a 2 gen thing? Don't the plug caps and wires just screw out? I thought they did anyway.

Yes, it's a second gen thing.

Wow, integral HT lead and coil? reeeeally? That doesn't sound very Yamaha-like

How does the 2nd gen do with COPs?

If it is just the cap, it is replaceable, they screw on. they are 10k resistor type Plug Cap Assy

4XY-82370-00-00

Yep! Just the cap. Thanks!

Yep! Just the cap. Thanks!

Look here maybe you can save some dough, the ones from Yamaha are $30.00

https://www.ngk.com/Motorcycle-Plug-Caps-c543.aspx

Look here maybe you can save some dough, the ones from Yamaha are $30.00

 

https://www.ngk.com/Motorcycle-Plug-Caps-c543.aspx

Wow that is more then what I paid for plugs, caps, and wires....

I tried that link and it returned a message that said, "sorry, we found no plug caps for your application". Did you find something else there?

I did, it had several pages listed, I did not go through them all because I do not remember what the Venture uses exactly.

I will try the link again.

My bad, I thought the page was updating as I input the various info to define the search so you could scroll through the list, but, you are correct when you hit the search button it responds as no matches found.

I was pretty certain that someone here on the forum had found those caps on the NGK web page in the past.

I had posted in the past a way to replace the wire and cap. I had done it on my 79 XS1100 and cut one of the coils off of my 05 Venture to show that it could work. I'm away for the weekend but I'll try to find my original post.

Hope this works.

http://www.venturerider.org/forum/showthread.php?106638-Gen-2-coil-frustration.

Sorry, I'm at a conference and only have minute to reply.

if you buy new ngk plug caps you need to talk to sales person as lower sealing cap lets water in. i replaced all mine that was the only thing that you have to do. they should have them. i talked to them about it. dont know if they followed up dont forget to get different bottom the one on it is around 25 thousand to small

Yeah, it's probably a design improvement having the whole cap/wire/unit sealed. Because as most of the 1st gen owners know moisture gets into the cap/wire joint and corrodes the wire and eventually causes a problem. The good part is that caps are $2.60 ea at NGK.com and copper wire is cheap. I suppose we should be using a touch of dielectric grease on the joints.

Just a thought... what do people think of using shrink tubing or some sort of sealant on the torn boot? Is this a suitable fix or should I move forward with a replacement?

Yamaha chose to make the wires a permanent install to the coils on my 1984 XJ750RL as well. This is not a new choice and procedure for them. I don't understand why they couldn't make the coils/wires/caps the same install as on the VMX12 line? Totall serviceable.

With my XJ back in approximately 1986 or so, I found and purchased NGK caps only and installed them on the original wire ends easily. I can't recall if they had resisters in the caps, or not. I may have removed them though. The resistors are to suppress cross channel noise with regards to CB radios etc. I've been told. The cap I found are two right angle shorter read for the outer cylinders and two longer reach/deeper much like the Venture and VMax units. They've worked great for the 30 some odd years I've used them.

ill post a picture when I get outta bed.

Just a thought... what do people think of using shrink tubing or some sort of sealant on the torn boot? Is this a suitable fix or should I move forward with a replacement?

That could work, not sure what the dielectric rating of the heat shrink is, if it is not rated for high voltage it may allow leakage voltage to "jump" through the areas where there is a gap in the original boot.

If you try it I would suggest getting the shrink tube that is adhesively lined that way it will be fixed to the boot and give a better moisture seal.

Clean the outside of the boot with rubbing alcohol and allow it to dry completely before applying the shrink. I would suggest having the boot installed on a spare spark plug when you shrink it that way it will not shrink down to far and collapse the boot. Depending on how stiff the finished part is and how much build up you get, maybe a second layer of shrink will be helpful.

Also coating the spare spark plug you use as a form for with a light coat of some sort of dielectric grease before installing, that way grease will act as a release agent in case any of the adhesive squeezes through the gap in the boot.

If you try it let us know, with pictures how it all works out.