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-   -   496 vs 525 value point in a 35 Donzi? (https://www.offshoreonly.com/forums/general-boating-discussion/337601-496-vs-525-value-point-35-donzi.html)

Indy 05-23-2016 06:56 AM


Originally Posted by Perfect Storm (Post 4442127)
The 525 EFI is a great motor, but besides the normal maintenance schedule on them, there are also known CMI header problems on a lot of these boats.

I know three people that had 525 boats and all three had header issues.

mummaiv 05-23-2016 07:29 AM

10K to freshen up one 525?



Originally Posted by Griff (Post 4442097)
I'd say it depends. Probably 10-25k depending on what exactly has been to the 525EFI boat.

525EFI's with 350hrs and never been opened are going need prob 10-12k+ worth of maintenance soon.
496's with 350 hrs will need nothing for a long time.


freebirdpa 05-23-2016 07:34 AM

10K and then some, don't ask me how I know!

neva satisfied 05-23-2016 08:19 AM


Originally Posted by Perfect Storm (Post 4442127)
The 525 EFI is a great motor, but besides the normal maintenance schedule on them, there are also known CMI header problems on a lot of these boats. I would thoroughly check out the CMI headers for any issues on any 525 boat that you are considering. Many 525 owners have had expensive CMI header repairs/replacement (myself included). The CMI headers are the weakest link on the 525 boats IMO. Only you can decide if the extra performance/speed is worth the extra expense and maintenance that you will have to endure...

I agree. The header problem is something that could come up regardless of how hard you ran the engines. Best bet is to change them out to something else or a set of Gen X. You think top end work is expensive? Go buy two sets of headers.

Sydwayz 05-23-2016 08:37 AM


Originally Posted by Griff (Post 4442097)
I'd say it depends. Probably 10-25k depending on what exactly has been to the 525EFI boat.

525EFI's with 350hrs and never been opened are going need prob 10-12k+ worth of maintenance soon.
496's with 350 hrs will need nothing for a long time.

What he said. You never know what you will find in a 525EFI with 200-300 hours, especially if it has never been touched.
Also, both motors have closed cooling systems. The only difference is the 496HO has the drain valve system whereas the 525EFI does not.

Jupiter Sunsation 05-23-2016 08:51 AM


Originally Posted by Sydwayz (Post 4442182)
What he said. You never know what you will find in a 525EFI with 200-300 hours, especially if it has never been touched.
Also, both motors have closed cooling systems. The only difference is the 496HO has the drain valve system whereas the 525EFI does not.


+1...... unless seller has receipts from a reputable engine builder in the last year/50 hours I wouldn't pay a premium on any 10 yr old 525's. I'd buy the 496 boat and run it until it blows up then repower with new engines.

As far as rebuild costs, compare cost of brand new power:

New in the crate 8.2 HO, $17,500: http://www.proboats.com/pre_owned_de...h=3016095&nv=y

New Merc Racing 520 (2 yr warranty), $24,000: http://www.proboats.com/pre_owned_de...sp?veh=3995570

LAriverratt 05-23-2016 09:16 AM

my 32 sunsation has 496 ho's...I wanted one with 525's but none that I liked and limited for sale at the time... hindsight I'm glad i have the 496's. right at 400 hours...ZERO issues with them!

Griff 05-23-2016 01:02 PM


Originally Posted by mummaiv (Post 4442152)
10K to freshen up one 525?

10-12k for basic top end's refreshed on twins.
Double that for complete rebuilds.

Wobble 05-23-2016 01:34 PM

It sounds like a 300 hour 525 equipped boat that does not have documented top end refresh and documented cmi replacement is not worth the same as a comparable hour 496 HO equipped boat.

ratedx 05-23-2016 07:48 PM

Thank you sooo much! Yes i had a 07 fountain w/525's and had header issues- I own a 07 Donzi now w/496's and it runs perfect(200 hours) with no issues ever- I have a chance to buy a 06 Donzi 35zr w/525's w/325 hours with no proof of rebuild(Repo) but priced very well.


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