ok Im thinking of getting a k&n filter for my 7.4mpi how many of you have put one on one of these motors and what was the results and how much did it cost? there are a ton of go fast products and half of the are all hype
Hey there CRMAX, Have a 2000 Merc 502 MPI MAG that I put a Vortec flame arrestor/filter on. Cant say I noticed any power improvement, but it did get rid of the vaccume cleaner sucking sound at engine start-up, and got rid of that black exhaust mess on the back of the boat. More importantly though I now have clean air going into my engine. A word of warning however!!! Do NOT buy the Vortec product. The one they sent me was a , "Pre-production model" according to vortec and does not have the SAE J1928 imprint on the filter. This leaves me in technical violation of the flame arrestor regulation. I have been fighting with the company going on a year now to get it replaced. They keep promising but no replacement ever arrives. Stay away from Vortec and stick with K+N.
Does the SAE J1928 have anything to do with USCG approval? I just bought by first boat this spring from a private owner. I question him about any upgrades that are possible or any he has done. One of the things mentioned was a different flame arrestor. He told me not to touch it because aftermarket will not meet Coast Guard Approval. I have not looked into it any further--until reading these articles, now I'm very curious. I do get alot of black exhaust on the back of my boat and would love to get rid of that problem not to mention gain a few RPM's(my brothers jet-ski just crawls by me). I have not questioned anyone until now about the flame arrestors, so I'm clueless. What brand(s)? What has it done......for exhaust residue, for RPM's, overall performance, speed? Where can I get one, how much $?
1996 Checkmate Convincor 253
454 Mag MPI (385hp at prop)
G.P.S. w/40 gals gas, single person =63.5mph
This brings up an interesting topic. USCG approval ?! What makes these K&N filters any different from the non approved ? I have both and there's no difference in appearance ?! One is tested and one is not. So charge extra for that USCG stamp on the filter ring. Realize they do not make a different recharge kit for marine filters ?! Hmmm.............................What a racket !
It was big money for the EFI unit, I bought an adaptor from Rex Marine so I can use the 500 efi style K and N ,,,, the whole thing ran me$160 I think,,,, didnt help much, but took away the sucking sound, and it sure does look pretty !!!