Did the 502 mag mpi come with two different flame arrestors stock? I have a 1998 and my arrestor only has a screen in the end, but searching for a new one i found this which has a screen all the way around like some of the upgrade kits with efi stamped on the end??http://www.doublerperformance.com/in...-flame-arresto
this style seems like it would be better than what i have?

My 95 502's have that style pictured in the link. I think they look cooler but who knows if they work any different. For the $400 they list that one for you could have one of these I'm guessing?

http://www.vortechmarine.com/products_03.php

Yeah that price is crazy just used it for reference I'm thinking with all the extra screen area it would be an improvement plus like you said it does look better wonder if its a direct bolt on for me

I think it is a direct replacement? Mine has four long studs that old it on. I really doubt there is any gains to be had between the two other than the aesthetics and probably not any significant performance gains with the K&N types either...

Yeah I've been reading not much in the gain department with the aftermarket flame arrestors but i can get the one like you have for $50 and think it looks better if it breathes a little better that could just be a bonus lol

Gen 5 engine has the screen/mesh on the sides with a metal cover that says EFI on the front. Gen 6 engine has the black rubbers ones with the filter just in the front.

You have the newer flame arrestor (screen on end). I can't vouch for which one is better other than Merc likely changed the style for a reason. My guess is intake flow alignment.

The early 90's EFI engines used a different flame arrestor, such as you pictured, and will not work on your 1998 502. If you have the
serpentine belt set-up like my 1999 502 then you need the style below. The two styles of flame arrestor mount differently.

http://www.knfilters.com/search/prod...x?prod=59-4542

I got my assembly from Dana Marine years ago. I did some testing and lost 9 RPM's at 5000 RPM's using the K & N filter.
I bought the assembly for better filtration since we have a lot of bugs and cottonwood trees around my area.

Weird you lost RPM's that's lame! Was yours an early style OE one or the newer OE version you replaced?

What?????

As stated earlier my engine is a stock 1999 Mercury 502 Mag MPI. I tested with the stock flame arrestor, none, and the K & N.
Using the stock one actually allowed for the highest RPM's but since the numbers were so low I consider it insignificant.