Spark Plugs, Mystery Engine, and Decades of Gas Engines

Reader letters about introducing high school students to gas engines, identifying a mystery engine, and spark plug cleaning.

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courtesy of Groveton High School

57/2/5: Another decade in the books

Mr. Ben Blodgett’s Energy Tech class at Groveton High School in Groveton, New Hampshire, has been going for 30 years! This photo was originally shared in the December/January 2012 GEM. Collector Mark Bacon (on far left) brought his Fairbanks-Morse to show the class. They also focus on hot air engines and old tools. Bob Roby also likes to assist with research and projects.

It’s great to hear another decade of high school students have been introduced to gas engines. Thanks for the share, Mark! – Editor

57/2/1: Continuing the spark plug conversation

I am a 68-year-old retired small engine mechanic. When I first started, I was 8 or 9 years old.

I made this my life’s work and did a lot of it as a Briggs & Stratton factory dealer. At that time we worked on a lot of B&S 5S engines that were on reel mowers being used every day. Later I taught small engine repair as an adult education class at the high school where I graduated. I taught two, 10-week semesters for almost 20 years. From my training directly with the B&S factory we were taught to NEVER use a sandblast plug cleaner on any small engine. The blasting grit gets caught up inside the plug and will remain there until the shock and heat of combustion loosens it, and it falls into the engine doing what it does best to the piston, piston rings, and cylinder bore.

New spark plugs are a small investment to make after spending all the time, effort, and money on a restoration.

That having been said, I have experienced less than a dozen times in my life when a new spark plug actually fixed the problem. If the existing plug is not damaged and is gapped correctly, it will usually be serviceable. Spark plugs are the least likely cause of any problems.

Thanks for the great magazine!

David Emond

This has been an ongoing conversation over the controversial technique of spark plug cleaning. The use of a pneumatic air spark plug cleaner was first suggested in the June/July 2020 issue of Gas Engine Magazine. Thank you for your experienced weigh-in on the topic, David. It’s great learning from reader experience on topics such as these. — Editor

57/2/2: Remember this mystery engine?

black gas engine from the front

In the October/November 2021 issue of GEM, Landis Wehrmann asked for help identifying this mysterious engine. Here are some of the responses:

Your engine is a Briggs & Stratton model FI. It’s missing the shrouds, fuel tank, carb, and intake. It’s an earlier version, as it has slant cylinder fins.

Tom Schaech
Pennsdale, Pennsylvania

The engine you posted in Gas Engine Magazine is a Briggs & Stratton model FI. This is the only overhead valve model they made back in the day that had a rocker arm on both of the valves.

Loren Ressler
Lititz, Pennsylvania

I would say for sure it’s a Briggs & Stratton. It looks rather like an FH model. I would need a closer look. I have two FHs, one is a rope pull start and the other is a pedal start, like this one.

close up of the front of a rusty gas engine

Jeremy Fryman
Marion, Ohio

57/2/3: Seeking information

I am looking for information, copies of owner’s manuals, brochures, or anything pertaining to these three diesel engines:

• Automann 2-cylinder vertical engine No. 1230, made by Mansons Auto International, Bombay, India
• Lister 3-cylinder engine model ST3 A30 engine No. US2521
• Bernard Moteurs type Brerete SGDG W51 engine No. 508944, S.A. Bernard Moteurs, made in France

Readers, send any information to Chris Porkholder, 1669-B Weeks Road, Panama, NY 14767. Thanks! — Editor

57/2/4: Help with Jumbo

I need some information on a Nelson Brothers 3hp Jumbo, the serial numbers match on the hopper ID tag and pulley flywheel, CC 6299. It has solid flywheels. I would like to identify the year.

Robert Cole

Please reach out to Robert, via email, if you can offer insight on his 3hp Jumbo. – Editor

Please send your questions and comments for Flywheel Forum or your contact information for GEM Experts to Gas Engine Magazine, 1503 SW 42nd St., Topeka, KS 66609-1265 or email

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