Spark plug bushing

[pbb]

I know a guy that has a 34 D. It has a bushing screwed into the spark plug holes in the block. It has small spark plugs screwed into the bushing. The plugs are small like the ones that goes in a Chevy or Dodge. Its the first time i have seen them in anything. Was it some thing you could get from the factory or was it aftermarket? What was the purpose of having them?The only thing i could think of would be a greater varity of plugs you could use.Just courious.

 

[Walt in Jaxn Tn.]

I think they were origionally meant for engines that burned excessive oil. They were popular a few years ago to adapt the old plug size holes to more modern plug types but, you have to be careful not to try to use resister plugs as they are said to cause early magneto failure.

 

[PopinJohn]

Here's the company that makes the adaptors, especially sizes for use with older John Deere. He also has a chart that lists spark plug brands and equivalent part numbers. I've used several myself with good results.
R E A M Corp
PO Box 311
New Lothrop, MI 48460
Phone 989-743-9148