| Author |
Message |
    
krossfire
Member
Username: krossfire
Post Number: 6
Registered: 06-2022
| | Posted on Sunday, February 25, 2024 - 08:05 pm: | 
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I have two 3 hp St Lawrence singles, and now a 6hp St Lawrence twin, and there are 4 different spark plugs in them�. What would be the proper spark plug for them? I�ve tried searching through this website but can�t find an answer� |
jim_parrott
Senior Member
Username: jim_parrott
Post Number: 227
Registered: 06-2009
| | Posted on Tuesday, February 27, 2024 - 06:44 am: |
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With buzz coils just about any plug that fits the hole will work. Put the two that are the same in the twin.
Jim |
bcm
Senior Member
Username: bcm
Post Number: 146
Registered: 11-2009
| | Posted on Tuesday, February 27, 2024 - 08:59 am: |
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Before about 1940 plug used 1/2" NPT thread. Autolite 3095 is ok and available at auto parts stores.
After 1940 plug used 18mm thread.
Champion D23 is a good choice, is very hot and is available but requires a search effort to locate source.
B |
krossfire
Member
Username: krossfire
Post Number: 10
Registered: 06-2022
| | Posted on Thursday, March 07, 2024 - 03:48 pm: |
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Surprisingly enough I bought some Autolite 3095, and they wouldnt fit, I checked the plugs that were in it and they are 18mm thread, so either I have an oddball or someone put later heads on an early model, its serial number 583, so that puts it pre 1920, so Ive ordered some D23s |
chris_spring
Senior Member
Username: chris_spring
Post Number: 286
Registered: 02-2019
| | Posted on Saturday, March 09, 2024 - 06:11 pm: |
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I found the same thing with my 3 hp St.Lawrence. A 3095 would not fit. A Champion 525 would.
Cheers! |
krossfire
Member
Username: krossfire
Post Number: 11
Registered: 06-2022
| | Posted on Saturday, March 09, 2024 - 07:02 pm: |
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Funny, I have two 3hp St Lawrence�s, and the both take 3095s�� |
