 | PM |  | | Quote | | | Reply | | | Full Topic | |
| Joined: | Sat Apr 29th, 2017 |
| Location: | |
| Posts: | 73 |
| Status: |
Offline
|
| Mana: |  |
If you need a colder plug, try NGK B9HS. They also make a B10HS and I assume it's one step colder. (NGK goes opposite the other mfr's; their plugs get colder as the numbers increase. NGK B8HS is approx equal to Autolite 411).
Your post says you have a Mc91B1. I believe that's the first Mc91x to use 12mm (.472") reach plugs. Look closely and you should see tiny text cast right into the head, next to the spark plug hole, saying to use 12mm/0.472" reach plugs.
Mc91B and earlier Macs use 9.5mm (3/8") reach plugs, and there is no text cast into the head. For those, McCulloch recommended Champion J2J (coldest), J4J (middle), J6J (hottest).
J2J crosses over to NGK B9S.
J4J crosses over to NGK B7S or B8S, or Autolite 353
J6J crosses over to NGK B6S or Autolite 303
I heard that some guys keep things simple by running Autolite 411's in all of them.
| Close Window | |