Spark plug set 816761Q16 is for use on V-6 MerCruiser engines with Thunderbolt IV ignition systems (1985 through 2003). The Quicksilver brand is the leader in delivering uncompromising engine oils, parts and accessories to the marine industry for over 65 years. Quicksilver is the premier supplier of...

The t-4 system is designed to increase performance from bottom to top, making it easier to ride faster. The stainless steel and aluminum construction offer increased strength and durability; ideal for racing and off-road riding. This system is also tunable, meaning you can remove the spark arrestor...

SPARK PLUG

Increased performance with World's smallest Iridium Center Electrode (0.4mm). To increase ignitability, the important point is to let the flame kernel produced by the spark to grow unobstructed. Normally, this can be accomplished by widening the spark gap. However, this causes spark voltage to incre...

NGK Standard Spark Plug is manufactured to enhance the performance of the vehicle. It is constructed from durable material that is corrosion and abrasion resistant. The spark plug insulators are made of 99 percent pure alumina silicate, allowing for longer insulator noses for reduced fouling. This s...

Designed specifically for the performance enthusiast, Iridium IX offers extreme ignitability, improved throttle response and superior anti-fouling. The 0.6mm laser welded fine iridium tip ensures high durability and a consistently stable spark and the tapered ground electrode minimizes electrical qu...

10 millimeter half-thread size, 19 millimeter (3/4 inch) reach, 11/16 inch (18 millimeter) Hex size, gasket seat, resistor, stud terminal nut, .035 inch (0.9 millimeter) gap, heat range: 16.

MFG# 113-4985 1134985

NGK (6544) IMR9D-9H Spark Plug - Pack of 1

NGK 5044 Iridium Spark Plugs - BR8EIX

Rugged, tough and reliable, invincible marine offers top of the line boating products and marine accessories at affordable prices, and is well-known for their hardworking nautical line. For freshwater and saltwater boating, invincible marine designs products for avid fishermen and weekend boaters. Q...

Manufactured from case-hardened chromoly steel. 'Parkerized' surface treatment provides rust and corrosion resistance, leading to longer overall sprocket life. The same great quality that the OEM's have trusted since 1946.