Quicksilver 805759Q3 Distributor Cap Kit for Marinized V8 Engines by General Motors w/Thunderbolt IV and V HEI Ignition Systems

Great OEM quality and a good price

The 805759Q3 Distributor Cap Kit (and similar OEM‑style distributor cap kits for marinized GM V8 engines) is a solid choice for refreshing your engine’s ignition system. Designed to fit marinized V8 MerCruiser engines from General Motors equipped with Thunderbolt or Delco HEI ignition systems, this kit includes the distributor cap, rotor, and gasket you need to get things running smoothly again. Built to meet original equipment specifications, the durable plastic cap resists warping from heat and vibration, and the brass inserts help fend off corrosion and electrical pitting — important for marine environments where moisture and salt air can wreak havoc on ignition parts. Pros: OEM‑grade fit and materials, corrosion‑resistant construction, restores ignition performance Cons: Requires proper fitment to your specific engine type — check your manual before ordering Bottom Line: A dependable and straightforward way to keep your boat’s V8 running strong. This distributor cap kit gives you renewed spark performance and durable construction that’s up to the challenge of marine us

I always buy factory parts-can’t go wrong 95% of the time-big issue with this product-bone heads at mercury think it’s funny to put bubble wrap around the rotor-place inside the cap so it will stick & jack up the gasket…-25 years and still Doing it…

Replaced my old one with this one and had no issues. It does not come with screws so don't throw your old ones away. It works as it should.

Exact fit and included the paper gasket. Kit does not include new screws.

So, I needed TWO caps and rotors since I have twin motors in my boat.....but there was only ONE Quicksilver OEM set in stock...so I ordered it, and then ordered a Sierra kit as well....and thought I would compare, and see if there is a difference! (Next season as I am on the dry for the season now...) Well right out of the gate, the Quicksilver product seemed better quality! The cap was just about the same as the Sierra, but the ROTOR was definitely better quality! The Sierra had a SCREW that held on the contact point of the rotor, where the Quicksilver was riveted! Also the rotor BASE was more substantial than the Sierra! Heavier, better fit and finish, plus the rotor shaft was BOLTED (Via three small bolts) to the base where the Sierra was held in with three screws! (They didn't even look to be stainless!) I am sure both are "OK" but the BOLTED set up looked a lot more sturdy and better quality! Why four stars? The OEM kit I received did NOT include new cap mounting screws!!!!! Not a HUGE deal...but one of my screws was bent, and I needed to replace it! So, I have not had it on the water yet so I may change my idea either way if one does not perform, but just based on initial quality, and workmanship, I give a nod to the OEM over Sierra! The Sierra didn't look "Bad".....just not to the quality and fit and finish compared to the OEM.......

Works great. Not like the cheap ones but didn’t cost a fortune

When I changed from my Siera cap and rotor, the thing that stood out was my new Quicksilver rotor having 6 slots vs 8 like the Serra. After full plugs and wires...boat ran like trash. Read reviews here and saw numerous people had the same issues months ago. This let me know Quicksilver shipping do not care about checking it's products when they know they have an issues. Now im sure I cant return it since its been installed....not to mention no bolts for the cap and the space is so tight that most bolts will not fit. I'll just buy from west marine in person like I use to.

Had a power and misfire issues…change the part with this one and all is working perfect. My engine is a mercruiser 5.7L black scorpion

Good quality cap has brass terminals,

perfect

I found bass swarf embedded on the inside of the distributor cap, which would cause misfiring. I was promptly sent a replacement.

Pricey cap but works well.