720 Spark Plugs

[Ron Muhlenkamp]

What Spark plugs are rec'd for a 720 two cyl.
20 minutes with the dealers parts man got no answer
Ron

 

[coonie minnie]

I use autolite 388s in my 2 cylinders. Autolite 3116 also seems popular.

 

[Hugh McKinney]

Champion J16's will get you by, and they are cheap. My 70 likes them just fine, although they are not much liked on this site, don't really know why

 

[SCATA Puller]

I run D21 Champions in all my Deere's, except my D which takes a bigger plug anyway since its a 1931. I haven't had any problems with the Champions so far been running them since I started rebuilding tractors twenty years ago. I went to NAPA and had them look it up since my 720 is an LP and they said the D21 was correct for all the 720/730 series spark ignition tractors. I thought in an LP you had to run a little colder plug but it seems to run fine.

I also run the D21 in my IHC H pulling tractor and they run fine there too.

 

[buckeye al]

Agreed. There is one hotter Champion 18 mm plug, the D23 which is a very big plug and usually it has to be ordered! It won't fit under the plug covers of an H. Few outfits stock them these days. If you order them you MAY have to buy a whole box. If doing light service and running K1, or a mix of #2 with some gas in an all fuel, you'll have the best luck with the D23. I've never yet had a D23 foul.

Some guys use the D16 in the old A or B because that's what they correctly remember using 50 years ago. But 50 years ago we worked these tractors day after day for all they were worth and then some!

Today fuels are different, oils are different and lets face it, few of us work them as hard today as we did decades ago!

Been a long time since I read the Champion book but what sticks in my mind was Champion listed the D16 as only suitable for extreme heavy service in the letter series JD tractors! I'd not put a D16 in any of 'em today!

 

[Mike Aylward]

I have had at least half of the last Champion plugs I bought be duds right out of the box. I wouldn't put a Champion plug in my lawn mower. On the Waterloo tractors I use 3116 plugs and have for many years. In my opinion they are hard to beat. And, they are a non-resistor plug, unlike the 386 and 388. Mike

 

[kendak]

3116 ....champion fishing weight

 

[fixerupper]

My 51 A and 630 are running Champion D21's because I got the plugs free. They have been running an estimated 10 years and haven't gone bad yet. Until I put the Champions in, the two bangers on this farm have successfully run Autolites for as long as I remember so I feel like a traitor running these Champions. LOL

 

[rick deere]

I use colder plugs on lp tractors'