I have a pair of 525 SC's in the Donzi and i'd like to do some preventative maintenance on them this winter. They have about 225 hours on them and run fantastic with no issues. What would be a few things i should think about at this point. Valve springs? Any blower service? what else? They have had regular service since new and really have never given so much as a hiccup. Just looking to stay ahead of it. Thanks all

What valve springs should i replace the stock ones with? Part #'s?

Weiand 256 blowers? Mine seized up @ 204 hrs. Although I dont know how well it was maintenanced before I owned it. I would say yes to having the blowers serviced @ 225 hrs.

This should be the 177 weiand. I would check the front and rear blower oil reservoirs for fuelish oil smell and if none present, just change the blower oil; 8oz front, 4oz rear. If you smell fuel you need new seals in the blower.

Other than that, it would be good to service the heads with a good wide margin valve job. You should not need new springs, just have the seat pressure checked and set. I would probably swap out the exhaust valves with ferria while in there, but that is just me. Re assemble top end with new arp head bolts and cometic mls head gaskets. Should be good to go well past 500hrs with this service.

BT

Do a leakdown test and repair from there. My exhaust valves leaked excessively @ 168 hours (and before) I did bearings/seals in the blower at about 200 hours. Mostly as a preventive step because I had gas in bearing oil. The OEM seals were a single lip with no garter spring (not so good). The bearings were normal 204's and were stocked at the auto parts store. Gaskets were expensive ($100-Summit) because they give you a whole bunch you don't use. While you are in there make sure you change the drive snout bearing, can't remember the number. If your springs are bad you can get you can get the exact replacements from Crane, they were the OEM supplier, look up the cam on their website, and the cam card will tell you which springs you need.

225hrs is nothin on a 525SC. Cam is low lift and valve springs are not an issue. The blower should be fine as you are changing the lube at least every 50 hrs. It can't hurt to have it checked, but probably not needed. Mine was still fine at 500hrs. Make sure to change the fuel pump lube as well. You could also do a leak down to make sure everything is still good.

Has it had ANY salt usage ever????? If so, pull the intake and inspect the water passages.

525sc, best motors I ever had, ran a triple setup for 500 hours with just light maintenance.

Great info guys.

Yes i believe they are the 177's. They have had regular service since new and i have not noticed any fuel smell. I dont think ( or hope anyway) that i need to get into anything deeply internal just yet, but do agree a leak down test is in order.

Old navy did you have your boat since new? Just curious as some of the things you noted seem out of the ordinary from what i have heard of the 525SC's. Thanks for the info on the blower, that backs what i have heard regarding the snout bearings and seals. I had heard to keep an eye on that stuff. so far so good but maybe an ounce of prevention may be in order.


Griff, no they have never seen salt. Yes all fluids are changed regularly. Like i said so far so good. For some reason i thought marine engines are just inheretly hard on valve springs (not sure where i got that from) i never took into account milder cam profiles. Thanks

They really have been trouble free since new. The first half of its life was kinda hard (but still regular service) and the last 125 hours or so since i have had it have been pretty mild. I tell ya one thing . . . i do like the blower whine these things putt off

I bought my boat used. It had "boatyard" type annual maintenance. I think that the exhaust valves were wrecked due to retarded timing. It just needed a valve job. I did not check the old springs since I put Dart Iron Eagles (308's) on the engine at that point with the same new spring as stock.