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Spark plug caps


docc

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Having shared my spare resistor with a friend needing one from a fall, I thought it would be good to source some replacements. It's always good to have a spare plug and cap on board just in case.

 

During my plug change, I split one of my original Champion boots using plug wire pliers. I think I have made the rubber very soft over time using dielectric grease inside the boot.

 

I was pretty jazzed to find exact replacements as Lambretta parts on eBay and had them really quickly from Welsh Scooter Parts, Newport UK.

 

A couple years ago, chasing my Nasty Hiccup, I found one of my plug resistors at 5,000 ohms and the other at 20,000 ohms. I'm thinking the state of tune is improved when they are the same and correct.

There were quite a few other contributors to the hiccup (erratic engine popping/ misfire), but the spark plug cap resistance is something simple to check during a plug change.

DSCN2769.JPG

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Having shared my spare resistor with a friend needing one from a fall, I thought it would be good to source some replacements. It's always good to have a spare plug and cap on board just in case.

 

During my plug change, I split one of my original Champion boots using plug wire pliers. I think I have made the rubber very soft over time using dielectric grease inside the boot.

 

I was pretty jazzed to find exact replacements as Lambretta parts on eBay and had them really quickly from Welsh Scooter Parts, Newport UK.

 

A couple years ago, chasing my Nasty Hiccup, I found one of my plug resistors at 5,000 ohms and the other at 20,000 ohms. I'm thinking the state of tune is improved when they are the same and correct.

There were quite a few other contributors to the hiccup (erratic engine popping/ misfire), but the spark plug cap resistance is something simple to check during a plug change.

 

Thanks for the info, Docc.. :thumbsup:

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Good find, I searched all over town looking for red caps and leads, they are unobtanium

 

I finally managed to find some on MG Cycle

 

Can you add the link?

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Good find, I searched all over town looking for red caps and leads, they are unobtanium

 

I finally managed to find some on MG Cycle

 

Can you add the link?

I tried before, here in the States, to find the red Champion caps with no luck outside the Moto Guzzi parts network. I forget how much they cost like that. The parts are made in the UK and cost me around $28US for the pair,shipped, and got them in five days (amazing!).

 

Unfortunately, the link is eBayUK and doesn't figure to last:

 

Lambretta Anti-Vibration Waterproof Champion Red Rubber Spark Plug Cap

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  • 1 month later...

Doing an ebay search, i find 2 different types of Champion red resistor caps... 

 

PRO5U

 

http://www.ebay.com/itm/320873934905?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649http://www.ebay.com/itm/320873934905?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

PRO5M

 

http://www.ebay.com/itm/321061987056?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 

Which (or neither) is correct for the V11 ?  What is the difference between these two caps ?   (my application is the 2000 Greenie)

 

Thanks in advance !

 

Steve Swan

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Same seller, so good question for them - what does the seller say the difference is? (His pictures look identical)

 

The ones original to my 2000 Sport were PRO5U (there is a piece of tape around the shank of the boot with this number). I assume the "5" is 5,000 ohms, but the "U" (or the "M") - don't know.

 

The only other variable I could imagine is whether the cap is dimensioned to capture the plug end with or without the screw on ferule (tip). The spark plug tips stay on with the PRO5U.

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I may be wrong but I believe the only purpose of the resistor is to minimize Radio / TV interference, I don't think it effects performance.

No doubt someone will correct me if i'm wrong. :grin:

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I'm not sure what 5,000 ohms would really do to the, what, 40 or 50,000 volts in the plug wire (?)

 

I did feel better when I found one side was 10,000 ohms and evened them out. Figured it couldn't hurt, but who knows if it really made any difference.

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