Hank36

Hello Guy's,I have a set of 525 sc's that will have close to 300 hours by this seasons end that have never been apart. I was wondering what kind of maintenance that I need to look at over the Winter to ensure that they continue to be trouble free except for the obvious impellars,plugs,fuel filters,oil change,drive inspection,etc.The engines run great and use no oil between my 30 hour oil changes and hold recommended boost @5000 rpm.The only issue ive been having lately is the port engine hesitates alittle when throttling up from idle and has backfired a couple of times and died.I believe thats in the carb and will look at having it rebuilt this Winter.Ive been told by different people to do leak down test on each cylinder of both engines,Change valve springs,Have blowers gone through,etc.I don't want to spend the $$$ if don't have to but i want to continue to have trouble free running time.Im not hard on my engines and rarely run over 4000 rpm's!!Your feedback in this matter would be greatly appreciated.Thanks Hank36

johnny b good

I know a guy at my rack storage marina that says he has 700 hours on his and they never been apart, They are in a 38 S.C. Fountain.

Hank36

WOW!!!!Thanks for the reply Johnny B Good.

GO4BROKE

Have you ever changed the blower gear oil?

Hank36

Yes,I change the blower oil every 30 hours when I do my engines.Hank36

Griff

Sounds like you're doing the same maint intervals that I did. I went throught the top end on mine at 340hrs, but ONLY because the Gil exhaust cracked and pitted an exhaust valve. I also added a roller cam for some more hp. The stock valve springs don't have issues and should be fine. Its only a .530/.551 lift flat tappet cam.

Mine had 475hrs when I sold the boat and over 500hrs when the new owner pulled it for bigger power. The blower was never rebuilt. Most people had to get them rebuilt at 200-300hrs. I changed the lube frequently(25-30hrs) and thats probably why it was fine. Make sure you are changing both the front and rear lube. They are separate. You could send the blowers in to the Blower Shop to be checked, but they should be fine.

Also, make sure to change the fuel pump lube regularly. Mine would become fuel diluted. I changed it about every other oil change.

The hesitation off idle is probably just the accelerator pump.

A leak down won't hurt, but as long as everything is running fine and you haven't lost any rpm, you probably don't need it. Also, you're not using any oil so the cylinders should be fine. Mine used a quart every 15-20hrs.

Do you have the Merc/Gil exhaust or CMI's??? If Gils, I would pull the risers and check the tops of the manifolds where the cylinder dividers are. Look for white crack lines. Thats where mine cracked.

Has the boat ever seen salt???? If so, I would pull the intake manifolds and inspect the water passages. Mine saw some salt before I bought it and the water passages where they meet the heads where in bad shape and had to be welded.

I have posted a lot of 525SC info over the past years. If you do an advanced search with my screen name and 525SC you'll find a lot of info.

johnny b good

Your welcome, but like everything there is always exceptions to the rule, I do know this guy with the Fountain is very meticulous with maintance and doesnt beat the crap out of his boat.

Hank36

Thanks for the info Griff.Mine came factory with CMI Headers and corsa silent choice which is good.I just got back from a 3 day weekend at Ky Lake and my boat ran great except for that little bit of hesitation that i mentioned on the port engine with the carb.I put 2 new fuel pumps on this winter due to one leaking throught to the inspection tube from the diapram.Ive got 8 lbs of fuel pressure and my boost on both engines is the same as is r.p.m.s.Did your engines turn over 5,000 at w.o.t?That's all mine will turn with 28 labbed bravo 1's on a outlaw v bottom hull.My manual said they will turn 5200 just wondering.I don't ever run them that hard anyway just curious.Thanks Hank36

mr.clod

A few things come to mind on your performance concerns. Typically, a manufacturer will give numbers under ideal, hard to duplicate, conditions. A waxed hull, near empty fuel tank, cool temps at or near sea level with blue printed engines and drives is not what you have. You should be proud you're getting what you have. Few people would justify the expense and inconvenience of rebuilding with the "hope" of gaining that 200 rpm. If you want to upgrade, that's different.

Hank36

I wasn't looking to rebuild or anything like that to get 200 r.p.m's.Just comparing to a fellow 525 sc owner who seemed to have alot of knowledge about the style of engines and wanted to make sure that i was doing the proper preventive maintenance on my Boat.Thanks hank36