Reliability
 

First let me say I understand high performance and reliability don't necessarily go together.

I read a lot of the 496s being the most reliable engines and I'm good with that, however there are not a lot of 496 fountains out there. I'm looking in the 35-38 staggered range. While I'm not et ready to purchase, I am doing as much research and homework as I can. I have the year range narrowed to 07-09. Really like the new interior.

I know the 525s are faster and I don't need the fastest fountain ever made. I have dreamed of owning a fountain since I was a kid. Finally coming into position where it will be possible without a strain on finances. I am my own mechanic in most cases so not worried about most problems.

My biggest question is as far as the reliability difference between 496s and 525s? I know that around the 200-250 hour mark valve springs need to be done. This is not a major thing and quite frankly not hard to do.

What are other reliability issues between the 2 motors?
Real world numbers on 35 and 38 lightnings with 496s and 525s? Preferably from people who own them or who have good friends who own them. Ive read all articles and blogs and whatnot concerning advertised speed. Looking real world.

As always I certainly appreciate everyones advice, insight and willingness to share knowledge and help a fellow fountain lover.

Mike

i have a 2007 38 w/525's full staggered -boat runs true 95 mph all day long! i would not consider 496 in a 38! however in a 35 with 496's you may see 78-82 mph. Both motors are reliable and virtually maintenance free. good luck in your search!

Thanks for the response ratedx. Appreciate the numbers.

Is there a certain year the header issue on 525s has been resolved. Is this still ongoing with hopes and prayers you don't damage the motor? If the factory merc/cmi's are still problematic is there a solution?

There are a few 42's here on Lake of the Ozarks with 496's run 70 all day long.

I've read so much on the cmi header issues my brain is spinning. Not finding anything recent on this issue. I've seen that Hardin has a replacement header. The thing that scares me most about the 525s is grenading and engine due to faulty exhaust.

Anyone replace thier cmi's?

I see a lot of people pressure test them but who's to say the day after testing it won't crack and destroy an engine?

Wondering what other solutions are out there as I am also not gonna be willing to spend 10000 every few years to replace headers.

Any help is always appreciated.

Mike

Here you go,,,,,,,,,

http://www.offshoreonly.com/classifi...o47331-en.html

That is a gorgeous boat. I had 496 ho and it is a very reliable motor if turn key is what you are looking for. Sounds like it has 1000 horsepower also.

Was on my friends boat yesterday, he has 525's with whipples. And he lost an engine while we were out. And it has bin broken all summer! Moral of that story leave stock mercury power alone!

That is mostly definitely a gorgeous boat. When I buy I want staggered and 07 for new interior. I do not plan on upgrading motors. Stock power is fine with me. Just worried about cmi's cracking which there are plenty of horror stories on here and other sites about.

I live in southwest Florida. Cape coral to be exact. So it will see mostly brackish and salt water. I clean after use and flush.

Just wondering If there was a solution to the cracking cmi headers.

Or anyone with high hour 525s? When I do buy the fountain I plan on having it forever and dying with it. Lol. I'm gonna be the old guy with the old classic boat we all see who has owned it for 25 years. Still tinkering and piddling with it. Hahaha

I've seen 496s held wide open for 30 plus miles and he does it every weekend. The motors dont even burn any oil 300hrs and counting! Blue motors run better but you're gonna need more maintenance around that 500hr mark like maybe head work but head gaskets are common. They are all great motors just keep good fresh oil in them. Leakdown test are great tools use them as much as u can

yes... pressure check them every winter and become or meet a good welder! Not many can't be fixed by a steady hand and a wire fed welder but they are always going to be a problem until someone comes out with a better solution.

I guess my biggest fear is passing the pressure test but be on the verge of cracking and cracking right after the test, then grenading an engine.

I'm still a lil sways away so maybe before I purchase there will have been a proven solution. So far I've found Hardin and stellings make a replacement set. Jury is still out as to wether or not they are any better.

I certainly appreciate everyones responses and knowledge on this.

Mike

i have researched the c.m.i. header issue and have tlked to c.m.i. engineers regarding them. The main reason there has been issues is from low water flow through the headers- if there is not enough flow there is too much heat to the inner welds. make sure you properly flush motors w/enough water pressure! also your impellars are in excellent condition.

496 has cast pistions:evilb:

Cast pistons don't scare me so much as I have no plans to raise compression or boost it. Also If I ever planned to build them the easy fix is a set of forged pistons.

Also I've read the cracking comes in on staggered with lack of support on long tails. Has anyone come up with supports to help prevent this?