The Buckshot Racing #77 Spark Tester is specifically designed for high-performance and racing outboards including; 2-cylinder, 3-cylinder, 4-cylinder, 6-cylinder, and even 8-cylinder powerheads.
 
Yes, both 2-strokes and 4-strokes such as the Mercury Racing 300R, 400R, and latest 500R. It can even handle the power of a Monty V8 with that super trick ignition. 
 
We've utilized the proven insulated tester body and built the best tester available on the market. Key advantages include:
 
A fully adjustable gap with accurate 1/8" incremental measurement points to record actual kilo volts (cheap sheet included) per hole
 
 Adjustable to a full .550 gap, enough, for example, to measure whether your Mercury V6 2-Stoke outboard is putting out a full 30,000 volts, required for peak performance on each hole 
 
Flexible, yet heavy-duty, 8AWG, marine-grade ground strap with ground clip to protect your ignition components
 
Fully encased and insulated body to protect from shock and possible fire caused by a rogue spark
 
Rubber boot insulators around each probe to further protect you and your equipment
 
Assemble here in the USA
 
Contact Mike Hill at STVracer@yahoo.com