View Full Version : Gimmee a boot---

brian Rupnow
03-29-2013, 10:17 AM
No, not that kind of a boot. The last 3 i.c. engines I have built all use either NGK or Honda CM6 sparkplugs. These are really nice little plugs, with an M10 x 1 thread that are the perfect size for the models I build. however, they have a weird shaped top on them that a standard sparkplug boot doesn't fit. And after multiple electrocutions, I have decided to put boots on them----And I can't find them. Neither can any of my local part stores. Can someone out there tell me where I can buy a rubber or silicone boot to fit these plugs, please.----Brian


Black Forest
03-29-2013, 10:21 AM
Try a shop that fixes chainsaw and string trimmers.

03-29-2013, 10:23 AM
Can you give us the diameter and length of the metal and ceramic parts? I make tooling for a place that makes custom plug wires for car, boat and cycle racing engines. I can check and see if they have anything that will fit. I have some extra leads lying around. If there's one that will work I'll send it to you for free.

03-29-2013, 10:23 AM
Or for a quick fix just get some shrink sleeve and call it a day.


03-29-2013, 10:40 AM
Try a shop that fixes chainsaw and string trimmers.

Yeah good idea.
If it's a Honda plug I'm sure they'll have a boot in their catalog to fit that plug.

03-29-2013, 10:41 AM
Just ask anywhere that fixes or sells small garden equipments, mowers, chainsaws brushcutters etc.
They almost all invariably have a plug cap which has no supression parts and is just a bit of bent metal with a rubber boot you slide over afterwards.
NGK do a cap made from rubber as well (tb05em for eg) as the more usual hard plastic ones (lb05f etc).

03-29-2013, 10:44 AM
Apologies my first post was under the impression you wanted sillicon instead of plastic to slip over the connector you already have, the bizarre plug shape just sank in and it occured to me you want a snap cap to suit your plugs.

Anyway, these guys have cm6 plug caps, about 3/4 down the page.

And ebay too

Weston Bye
03-29-2013, 10:51 AM
Brian, A resourceful guy like you should be able to make a split aluminum mold with a core pin for the wire passage intersecting another core pin at right angles for the plug passage. Inject silicone or some rubber compound and let it cure.

You might want to use a 2-part molding compound as RTV and others single-part compounds depend on some air or humidity exposure to cure. Or use RTV and wait a long time.

A.K. Boomer
03-29-2013, 10:55 AM
Chuck it up in a three jaw and turn it down?

03-29-2013, 12:37 PM
Why not bodge something out of some thick walled, very elastic, synthetic rubber tubing? It may not look pretty but if it was sized appropriately it would probably hold tight and prevent shocks.

You might have to modify the connecting wire so that it wasn't coming off at a 90* angle from the plug.

At least it would be a quick fix until you could source the real boot.

brian Rupnow
03-29-2013, 02:43 PM
Okay Guys---thank You---I had ordered parts from S and S engineering 2 or 3 years ago when I built the Kerzel, but couldn't remember their name. I have just ordered 3 boots and plug wires from them. I know that I could make a mold and make my own silicone boots, in fact there is an excellent "how to" right on this forum, but I'm lazy today.----Brian

03-29-2013, 04:20 PM
Ehhh, I would wrap the wire around the end of the plug, put a huge peice of shrinkwrap or some other tube around the plug, then flood the area with silicon.. Or hot glue if im really lazy/in a rush. (then again, hot glue would likey cause the shrinkwrap to shrink..)

Only problem is it will be a pain to remove if you can't take the spark plug with it.

brian Rupnow
04-08-2013, 05:51 PM
The sparkplug boots and wires that I had ordered from Roy Sholl at www.cncengines.com showed up today, and as usual they did a great job, and the boots fit the CM6 sparkplugs perfectly. Thanks Roy, and I'm posting this as a heads up to anybody else looking for this type of sparkplug accesory.----Brian

04-08-2013, 07:31 PM
Ever think about Rajah connectors?

brian Rupnow
04-08-2013, 07:35 PM
Ever think about Rajah connectors?
Nope---Sounds like something you would use on a tiger.

04-08-2013, 07:59 PM
Rajah connectors were often used on race engines, i used them years back, but i don't think they apply to Brians engine as they are pretty exposed, at least mine were.