When will thes 525s require work?
 

I'm in the process of buying a 2005 Fountain with twin 525s. Dealer confirms boat is freshwater only and regularly maintained. Motor run check showed total 158 hrs of which 88 hrs at idle to 2000 rpm; 45 hrs to 3500 rpm; 18 hrs to 4200 rpm; 6 hrs to 4700 rpm; & 1 hr to wot. Will it be necessary / recommended to pressure test headers, replace valve springs or other preventative measures on these motors. Would you recommend a compression test or leak down? Any information is appreciated. Thx Greg

A compression test is easy but a leakdown would tell you more. With a 158hrs at those rpms I would think the motors would be in great shape. If the oil was only changed once a year that is less than 18hrs per oil change...damn good if you ask me.

As far as the headers...I think there is quite a lot of hype here on OSO about them. I personally think that the problems are with a small percentage of the headers...freshwater anything would make me feel better. I have no data to back that up.

I would doubt the valve springs need to be replaced yet, but really, that is not a big cost in the big picture unless you buy the springs from merc.

That's really low hours for an '05. A compression test is easy and a leakdown test is more to pin down a problem if you do find a cylinder with low compression. I'd bet the headers are fine especially if the engines are side by side without long tails. Some Fountains did have issues with rot in the transom or stringers and I'd maybe look into that too. Good luck, sounds like a nice boat. edit: Compression should be 140 psi with little variance. If done cold it will typically be around 135 psi on a healthy engine.

All boats have had issues with rot on transom and stringers not just fountain

I would at least do compression and to be on the safe side pressure check headers. I'd rather no for sure they are good than to think they are and ingest water.

True. I didn't mean that as a cheap shot against Fountain. Pressure checking the headers is a good idea but I doubt the seller would allow the removal of the headers before the sale.

The last one we looked at the past 2 years was a 2011 year model needed Valve springs at 300 hrs, plus check the heads and clean them up as well and believe it or not lifters at 390 hours. Motor was well maintained by owner but half its life was ran hard. Also needed a new XR outdrive around the 325 hour mark. - gear oil changed every 30 hours as well.

Definitely do a compression and leakdown test. If all checks out and you buy the boat, definitely pressure check the headers. My previous fountain was a 2005 with 525's and 110 hours. My headers were leaking and it cost me an engine. There is no rhyme or reason to whether they fail or not. You're better off knowing for sure.

Is a leakdown test really needed if compression is 135-140 in all cylinders?

If it were my money, I think so. IMO, the leakdown test is more important than the compression test. Good compression doesn't always mean everything is fine. It is certainly a good indicator if the compression results are not good, but a leakdown will tell you if there's excessive blow-by which is a better indicator of current / future problems.

doubt the valve springs need to be replaced yet, but really, that is not a big cost in the big picture unless you buy the springs from merc. http://goo.gl/7cEs61