What kind of spark plug do I need?

[brileywayne26]

I’m trying to get my great grandads old model engine collection running again starting with this bad boy and being new to this hobby and this being an older machine I have no idea what spark plug to put in this. any help or information would be greatly appreciated

 

[GreenTwin]

I am trying to get into some gas engine builds, but still learning on that front.

I did find some spark plugs that are small, but I am not sure if they would fit or not.

You will have to figure out what your threads are.

There was a thread about this not too long ago; I will see if I can find it.

.

 

[GreenTwin]

Some info here:

https://www.woodysengines.com/shopping.htm#!/Spark-Plugs/c/31990222
and more info here:


https://modelflight.com/product/spark-plugs/
.

 

[brileywayne26]

Some info here:

https://www.woodysengines.com/shopping.htm#!/Spark-Plugs/c/31990222
and more info here:


https://modelflight.com/product/spark-plugs/
.

Thanks for the info just ordered the one I needed it was the (3/8x24) I’ll be sure to post a video of it running soon

 

[Aerostar55]

View attachment 151020View attachment 151021I’m trying to get my great grandads old model engine collection running again starting with this bad boy and being new to this hobby and this being an older machine I have no idea what spark plug to put in this. any help or information would be greatly appreciated

At first glance it appears to be a Philip Duclos design called the odds and ends hit or miss engine from home Shop Machinist magazine. I can’t remember what spark plug he used in that engine. Looks larger than 3/8-24 which is used in many older model engines. You could try a small weed eater plug, or plug from A chain saw.

 

[AndrewW]

Thanks for the info just ordered the one I needed it was the (3/8x24) I’ll be sure to post a video of it running soon

Just for info. The odds n ends engine drawing shows a Honda cm-6 spark plug which is M10 x 1. Mind you, when I made mine I used a 1/4" x 32 plug cos that is what I had kicking around.
I hope you get it running soon.
Cheers
Andrew