When to Freshen Up 525's
 

Happy New Year Everyone,

My Boat has 525's in it with about 170 hours, run in fresh water and salt water, always flush, oil changes every 25 hours on motors and 50 on the drives. Drives pulled and alignment checked 2 times a year.

My questions is when do I need to consider something more than the "routine Maintenance" on these motors?

Thanks,

Mark

Re: When to Freshen Up 525's
 

You're really opening a big can of worms here,,,,,,,,,,,,
200 hours would be a good time to pull the covers and visually inspect the valve train, possibly checking the spring tension.

Re: When to Freshen Up 525's
 

My buddy's have 350 hard hours (4000-4200 cruise), mostly salt water and have had several header failures. At this point each engine had weak cylinders at 7 or 8 or both (likely due to the header leaks). The engines are torn down now and the main parts (block, crank, heads) are serviceable and could have simply been freshened and re-used.

Re: When to Freshen Up 525's
 

Do the valve springs. At the same time you can check the external electrical components, Dizi, starter etc and have a good look at the entire valve train. If it leak down tests OK and oil preasure is ok then you are good to go. Springs, keepers and retainers are cheep, Holes in pistons are expensive. With what we have learned with our race boat, I would change lifters and rockers, But thats me being a little fussy, MAYBE. Jas

Re: When to Freshen Up 525's
 

hey Mark .... checking the Alignment twice a year? ....do you generally have to make an adjustment ?

next question would be dont 525's have solid mounts ?

http://www.mercruiserparts.com/Show_...tes+%2D+Engine

Re: When to Freshen Up 525's
 

What year 525's are you all talking about..sc/sci?

Re: When to Freshen Up 525's
 

Thanks for the info guys.

By alignment, I mean remving the drive and checking the driveshaft alighment and also checking the visible parts for any wear an tear. Checking Bellows and lubricating everything. So far no problems at all.

The 525's are EFI built in 2005.

Will most likely check valve train after this season in Florida along with other routine maint stuff.

Re: When to Freshen Up 525's
 

We have about 280 hrs on ours and are doing the springs this winter. We have also had numerous header problems.

Re: When to Freshen Up 525's
 

with solid mounts there is no adjusting ..not trying to bash your method .. I am repowering and planned to go with solid mounts ... I was concerned about getting it right and at 600hp was discouraged from using them .. Again with no more time it takes to pull the drives its prob time well spent ....

Re: When to Freshen Up 525's
 

I should clarify, My Mechanic/Wrench Guy checks my drives. I thought there was an alignment, apparently not.

Re: When to Freshen Up 525's
 

I'm interested what kind of problems you had with your headers. Mine cracked at the "diamond" welds where the four pipes combine to one. I got some water in my oil which clogged the filter then sent my oil temps high. Only happened on one motor for me so far. Checked the cyliners for scoring and compression everyrhing OK.

Re: When to Freshen Up 525's
 

I have seen these motors fail at 80 hours and make it 200 hours. However, the motors I have seen for more preventative maintenance have the higher hours to show for also.
Your mechanic is probably pulling the drive off to grease the input shaft every 25 hours if the alignment is good and the motors are raced mounted. This is also a good habit to get into. I would start with cylinder leak down on your motors and they should be around 10%-12% with your motor and hours on them. Compression check is more of a waist of time for good info.
Have you used good quality fuel even though they only require 87 octane?
170 hours is getting up there for hours on the cylinder heads with the spring psi and fuels these days. If you are going to continue to run with out doing valve jobs just continue with cylinder leaks downs more often..
Thanks, Cam-shaft/

Re: When to Freshen Up 525's
 

I have seen cracked headers at the collector in which you are reffering to. This later caused a spun rod bearing, in which there was an oil temp issue. The bearing failure was probably due to debtination from water in the combustion chamber. Thanks Cam-shaft.

Re: When to Freshen Up 525's
 

CMI Sport Tubes leak unless they have the "cool collar." If your headers leak, buy new ones. They are $12k.

Been there, done that

Re: When to Freshen Up 525's
 

Hey Mark ... I understand ... I'm no expert and just try to soak up some info .... Some people try to lube the Coupler and U joints in the boat ..but I'm sure removal is the way to go ...Seems the solid mounts are better too ...I lloked and almost if not ALL HP merc motors have had the solid mounts for a while. ......m

Re: When to Freshen Up 525's
 

I have 310 hours on my 2003 525's. No signs of any problems but I believe that preventitive maintenance is the key to a happy boating season.

New springs, retainers, and valve job.
New CMI headers with the cool collar upgrade.
Complete drive overhaul with new gears and bearings.



Jay

Re: When to Freshen Up 525's
 

stop buying tubular headers and get a set of stainless marine...............they are pretty(cmi) but they always seem to give people a problem...................just a opinion .............

Re: When to Freshen Up 525's
 

My S/M dry pipes are 12yrs old, only salt water, I flush them after use 1994 to 2006:D and they sound great loud:p :D