ajc7200

Guys thanks for all the feedback. Made up my mind! They're staying stock and going in the bilge asap!

Griff...have you ever had injectors cleaned? What's your top end rpm's? Heard if you clean your injectors you gain higher rpm's?!? Is it hard to do?

Thanks again!

VoodooRob

Bup on here does injector flow testing and cleaning. Very detailed work.

johnny b good

Same here at a touch over a 1000hrs

liquidlounge

iTrader: (1)

I guess you know when you are past the pinnacle when you join the stock motor fan club. Really, the Mag motors are fantastic as they sit. If you think of them more like outboards that just carry a HP designation, then they are the best and most trouble free 400HP I/o ever built. You can enjoy the boating hobby for decades when you are just doing oil changes and impeller swaps. In addition, I would bet that 95% of performance boaters over 50 if they swapped on a B3 from their B1's that they would never change back (or bother to!). I did it just for kicks from a project boat, and I thought how could anyone not love this? No more bow rise getting out of the hole, people can sit where ever they want with no lean, pull into your slip like driving a car, better acceleration, less cruise rpm. I definitely use less fuel. A great match and often overlooked for most Mag equipped boats.

ajc7200

Liquidlounge are you saying us stock guys are old? Lol! Not 50 yet but working my way up there! I've only heard great things of these 502 Mag motors so happy I was able to purchase a good pair. And hearing the engine hours from Griff and johnny b good just helps reassure I made a good decision. I started this thread because I have a set of Merlin Heads from my 454 build (currently for sale on eBay as well as my 454 short blocks) which I was debating installing on my 502's. I got great advise on here and staying stock. Just the thought of any disassembly makes me cringe! Changing a bad coupler started an overhaul process that has now lasted 2+ years. No regrets but want to get back in the water!

I've been on cruisers that have Bravo 3's but never experienced them on a performance boat. I traded my B1's and now have XR's.

Thanks for all the great advise!

Griff

No I have not had the injectors cleaned. I checked after originally posting and actually I'm at about 620hrs on my engines.
I'm going to change the spark plugs weekend and will see how they look. The original sets of plugs had about 350 hrs on them and still ran fine. I actually didn't know they had that many hours on them since I bought the boat with 230ish hrs. the plugs I took out still had black overspray paint on them.
I run 5100rpms at WOT which is just shy of the rev limiter.

ajc7200

You brought up an interesting subject; spark plugs. I was thinking of having them changed before dropping in the engines. What spark plugs do you use? Saw a thread on here and most guys were recommending the AC Delco Spiitfires. I would think the NGK Iridiums are a good choice. Did some research yesterday and these "Brisk" spark plugs popped up on Amazon. https://www.amazon.com/dp/B00862483Y..._cg0azbHR510Z6 A set of 8 plugs run $132.00?!? Your thoughts?

Griff

Just run the stock NGK BR6FS plugs. You won't see any performance gains with the exotic plugs.

ajc7200

Update: Sold the heads!

FYI - have the following parts for sale. If I don't sell them soon I'll list them on eBay.

1) Gaffrig twin throttle controls (4) in color Yellow. Setup pattern is shift - shift - throttle - throttle.
2) Imco PowerFlow Plus Manifolds and through hull risers exhaust with Imco Gatlin Mufflers. 2 pairs
3) Eddie Marine Stainless Steel Flame Arrestors - quantity 2
4) Eddie Marine Aluminum Valve Covers - 2 pairs
5) Mercruiser flywheels - quantity 2
6) Mercruiser flywheel covers - quantity 2
7) Mercruiser couplers - quantity 2

Can provide pics upon request.

Thank you!

F-2 Speedy

iTrader: (6)

put some 16.00 ac delco's in it and go boat, why would you not change, plugs,wires, impeller cap and rotor while the engines are out