525EFI Valve Springs Concerns
 

I just picked up my '04 Fever with the 525efi this fall, before I picked it up I had Merc certified mechanics survey it. The engine has 280hrs. on it, 100+ hrs under 2000 rpms and very little time wot, from what they seen it wasn't beaten on. They performed an engine leak down test and said all off the cylinders had great compression and all were almost exactly the same. So my question is when people suggest replacing valve springs on these motors around 200-300 hrs is it because the valves springs are getting weak which will affect compression when the valves don't seat as good or is the worry a spring breaking and dropping a valve and totally f-ing up the summer. So Im just wondering whats the main concern when these valve springs get hours on them, compression or breaking?

Both. Perhaps the bigger issue is not outright breaking, but springs losing seat pressure over time from heat cycles and compression cycles. If the correct pressure is not maintained, it can allow the lifter to lose contact with the cam lobe and even "loft" over the nose of the cam. That puts tremendous pressure on the lifter wheel and can lead to early failure. You can also have harmful harmonics develop in the valvetrain with weak springs that can lead to damage.

It is possible to check spring pressure with a special tool without removing the head, if you are worried that you may be on the edge. But a good set of springs like the Isky Tool Room series might be worth the investment to set you mind at ease and ensure a trouble-free summer of boating.

I think the concern is the junk parts mercury built the valve train with. There are much better springs and lifters for less money than the stock stuff. With 280 hrs I would definitely look into updating the valve train.

I am going through a valve spring replacement right now on my 525's. I can tell you what I've learned in the process and pass along the info from the pros that I've been speaking to. The 525 OEM springs install at a short height and do not have enough pressure to handle the lift of the 525 cam. The springs are really too light on the seat. Despite the fact that the Merc manual indicates an install height of 1.850, all three of my motors have installed heights of 1.810; all factory stock. Given that the springs lose pressure over time and that they start out being too light, eventually you run into a problem where they cannot effectively control the valve train and then other bad things can happen.. I bought my current boat with 120 hours on it and all three engines had excellent compression and leakdown tests. At 204 hours, I had a rocker arm failure on my port motor resulting in a new long block. My reason for changing the valve springs started out being the result of what I heard about hours but the more homework I did, its more about putting the right components in there period.

On a related topic about the 525, if you have Silent Choice exhaust, you should seriously consider removing the headers and look for signs of reversion in your exhaust ports. I've also discovered this recently and apparently is very common with rear mounted 525's with Silent Choice exhaust. I mention this in the context of valve springs because if the valve train is not being controlled properly, you can also have reversion.

Do a search on posts from Eddie Young about 525 spring / valve train issues. It's not just springs.

http://www.offshoreonly.com/forums/g...ml#post4203256

Our boat has 575's, and a rocker arm was starting to fail (loose needle bearings) and one valve spring had failed both motors at 260 hours. Luckily, I shut it down and took it to Eddie before any further damage. ...and we're picking the boat up in the morning - will be so glad to have it back!

Yup.. I started that thread and Eddie is one of the "pro's" that I was referring to. I am also changing the rocker arms..

River Ratt... aren't you glad you asked?? :party-smiley-004:

What kind of exhaust do you have? If they are CMI. Check them also.

Thanks for all of the info fellas, I can learn so much so fast on this forum, it rocks! I am glad I asked. Yep I've got the CMIs which are currently sitting on my toolbox in my garage, I pulled them off before putting the boat in storage to pressure check them this winter. If they pass I will be pressure checking them after every cruise and be replacing them with Stainless Marine exhaust the second I don't like what I see. I don't have silent choice which I'm glad. Now the question is since Im pretty mechanically inclined do I do the springs/rockers my self or pay the big bucks for someone else to do them? I know there is a way to do it with the heads on the motor by pressuring up the cylinder with air to hold the valves then swap stuff out but Im not sure how complicated it is? Since my headers are off now would be the time. Decisions, decisions......

I am pretty mechanically inclined as well but was initially afraid to it myself. But I did a little research, talked to some friends with experience and bought the right tools and it's pretty easy to do. I am doing it with the heads on the motor, pressuring each cylinder to swap the parts. You also need to set the valve lash after changing the springs whether you replace the rockers or not. You also need to measure the installed height of the springs as they are now before you replace them..

My 525 is in the shop getting new stock springs, retainers & keepers installed. Leakdown test was good. Not going to second guess Mercury on their choice of springs. How many years has the 525 been in production now?

im not arguing with you but quite a few members tried to steer you in the right direction.mercury marine buys parts to get the engine past the warranty.they will use the cheepest parts that will accomplish this.the bean counters dictate what parts merc selects,not the engineers.if you talk to bob madera he will confirm this.yes the merc replacement parts will work but they are not the best choice. imo you could have got better parts for less money just by picking up the phone and calling bob.

Mercury uses Crane valvetrain parts on the 500's/525's, and etc,etc.. Crane is an aftermarket company. Therefore, you know aftermarket companies offer many different variations of the same part. Many valvespring choices, etc,etc.

With cars, boats, sleds, bikes, etc,etc somethings, yes, the factory parts are better. With somethings, the aftermarket parts are better.

90% of the time if a person or mechanic is not sure if factory or aftermarket is better, than going with factory is a good decision to make.

I couldn't agree more with you Mike. I've spoken at length with Bob and other very well respected performance engine guys and they all agree about the parts used in the stock setup and if one takes the time to really listen to what they are saying.. it's very scientific and makes complete sense. And the truth is that there are enough failures out there to back up their claims. In all three of my engines, the valve spring installed heights are not even up to the spec that is in the Mercury manual and they are bone stock. What does that tell you? It means, they were assembled to "good enough" tolerances..

I still think the 525 is a great engine, but it has weaknesses and it's a choice to make on how much risk to assume. I'm going to do anything I can to prevent another catastrophic failure and that means upgrading the valve train. Not trying to start a debate, just saying what my choices are. For the record, I've gone with Isky Tool Room springs and Crower stainless rockers.. overkill?? maybe... but what do you tell yourself if you cheap out and then the motor grenades on you....

toolroom springs and crower ss rockers is what merc should have went with but then they would sell a lot less parts down the road.i have never seen an engine fail because someone used better than stock parts.

Used this same combo a few years back on my 500's when I had them done. Overkill, maybe but you do get what you pay for with these manufacturers. Part number of the spring you used?

valve train issue are the #1 failure in these engines, almost always starts with the springs, rockers right behind, anybody that has run these 500/525hp's should be very aware of the ticking bomb over 250hrs, also merc does not make valve springs, as a matter of fact there are only 2-3 manufactures of spring period, many companys sell them, few make them, PAC, PSI are 2 that do and have very good product, when doing the replacement new retainers/keepers should be part of the job as well, also set the installed height correctly...not hard but may just throw them on...kinda that pull and pray deal...the last thing if you are redoing the whole engine DO NOT restrict the oil to the top of the engine(this was a oil drag race trick even I used to do to keep more oil down low) but the oil spray is the only COOLER for the spring that get unreal heat build-up..remember breaking a spring or rocker can cause the retainer to come off dropping the valve and it's not pretty nor cheap after that..

I should have said stock spec parts (Isky). My engine showed no problems after about 350 hours and I run it at 5,400 on top. I do not see how adding more pressure and stress to the valve train will help things. I'll stay with Mercury's choice of spring pressure.

Which part # spring did you go with? What is your install height ?

I'm at work now and don't have the part numbers here. Maybe Brian Orlandi will see this and answer or I will find out later. Normally I would do this myself but Brian did a leak-down test and a visual of the combustion chambers with a scope and there was no sign of reversion. He will check installed height. Also, I have silent choice and it is fine if you only use it at idle. I pulled the headers and will pressure test them before re-installing.

Isky tool room 9905 springs.. Crower Enduro SS rockers..

Silent Choice and 525's are NOT a good combination especially if the motor is close to the transom. This is what 525's do when you have Silent Choice. And before anyone chimes in and says this is from leaking headers, it's not. I've done extensive pressure testing on the headers with not a single leak. Using the Silent Choice is NOT the problem; the problem is that the reversion is caused by the tails being short and the water dump being too close to the collector and the exhaust pulse sucks the water back in when idling. This is a known issue with 525's and silent choice and another one of Mercury's dirty little secrets. Don't believe me? Call Mercury and ask them about Silent Choice and 525's and see what they tell you..

[ATTACH=CONFIG]533769[/ATTACH][ATTACH=CONFIG]533770[/ATTACH][ATTACH=CONFIG]533771[/ATTACH][ATTACH=CONFIG]533772[/ATTACH]

I've seen that on a few 525's that I've worked on.Your not alone.

Do you have the proper Z shaped divertors? They dump the water further downstream then the standard Y pipe does. I haven't had any issues and the Mercury 525 service manual says that Q&Q exhaust can be used up to 2,500 RPM. I only use mine sometimes at idle. Since my headers never get hot I also left the water flow restricters in place.

The Isky part number for stock spec replacement springs is 8005A.

http://i763.photobucket.com/albums/x...s312Medium.jpg

did you happen to notice a ramp to reflect water some what.couple I did,had them.

Yep... my setup looks (looked) pretty much the same as yours. If you're not getting reversion, consider yourself lucky but it's something to really keep an eye on. I had absolutely no indication this was happening. I had been pressure testing my headers every 10 hours and had no reason to think there was any problem. Then I pulled the headers to do my valve spring replacement and this is what I found. I should also note that there wasn't a single speck on the exhaust ports of my center engine and that one does not have Silent Choice. I'm pointing this out to you for your information to hopefully save you and others from very costly repairs down the road. I'm having custom dry tails made and removing the silent choice; I've already replaced two long blocks in the last two years. I lost one on my 38 Fountain to leaking headers and one this season on my 47 to a rocker arm failure; trust me.. it sucks...

I can tell you this for sure: Merc. and CMI didn't offer the Silent Choice. Fountain, did that one their own. This was due to customer request, if you look at the down diverter tube, you will see, it's going in the opposite direction, than the normal install from what I see in your picture.
A friend of mine worked for Merc Racing for 32 yrs and was active in the project. He stated to me, they didn't want silent choice on that package and also speaking to someone else, highly involved at Fountain, stated to me the factory added the silent choice.

[ATTACH=CONFIG]533794[/ATTACH] This is a 47, I sent to Acapulco. The boat has CMI Aft Fire Mufflers, from factory. I think; Fountain, may have changed their thinking at some point.

Hy5, Is this caused from salt water usage? I get the reversion issues but the pics look like ports are all pitted. Again I get the reversion issues but the pitting is from salt water yes? My pics are not real clear so maybe I am not seeing it correct. The reason I ask is I also have a 525 / 47boat & 2 years ago I did not have these issues.
Thanks

That looks like someone added dry tails and mufflers... proving my point I think..

OzarkDevil, yes, this from reversion in salt water. The ports are not actually pitted. What you are seeing in the pictures are dried salt crystals; they are just exaggerated by the magnification in the pictures. If this was fresh water, the reversion would still be happening, it just might not have been as obvious. The salt makes it stand out like a sore thumb.

It's in the official Mercury HP525 EFI service manual that silent choice is OK to use with the 525 but only up to 2,500 RPM. I also see it as kind of a safety device that will dump any water that may get past the flapper down the down tube and not over the hump. I don't see how it can cause reversion. When you look at my pic you can see that you really can't dump the water any further downstream. There must be another factor at work on the boats getting reversion.

Have you considered the fact that the manual might have been written a number of years ago before these issues started to surface? Call Mercury now and see what they tell you.

The issue is that because of the silent choice, the water dump is forward of the hole in the bottom of the tail that goes down to the Y-pipe. That places the water dump inside the pipe too close to the collector. The duration of the lift on the 525 cam causes there to be suction and because of the proximity of the water dump to the collector, that water gets sucked back in. Think about holding a garden hose in your left hand and then holding a vacuum hose in your right perpendicular to the garden hose but only a few inches away, turn the vacuum on and chances are some of that water coming out of the hose is gonna get sucked up in the vacuum... that's what's happening... it's not the use of the silent choice causing the problem. This really only occurs at idle because at higher RPM's, the exhaust pressure blows everything out the back. This is pure physics.. I've explained it several times and I've confirmed with reputable engine guys that they are seeing this problem frequently. I'm spending about $5000 to fix this problem with new custom tails; if I wasn't 100% sure this was being caused by silent choice, I would not be doing that. It's because I've chased down all of the possibilities.

I've posted it here to help; if you choose to ignore it, that's your choice.

Here's what my setup looks like..

[ATTACH=CONFIG]533848[/ATTACH]

I did do a lot of research on this before repowering to the 525 and I was ready to give up the Q&Q but enough people convinced me that I could keep it and I have not had any issues. My mechanic just put a scope in every cylinder and did a leak-down test and everything is fine after 7 years and 300-350 hours. I will call Mercury and see what they say about Q&Q now. My manual is 2007 vintage. I paid a lot of money for those diverters and to have the tips relocated and it's been working fine. I am sorry that you are having these issues. I really am.

Update: I did a leakdown test on both back motors and got pretty bad results; 70-80% leak down on two cylinders on the starboard motor and 25% leakdown on the port motor, which is a new long block with 18 hours on it. Cylinders 3 & 4 on both engines are the ones affected; those are the shortest runners on the headers. So what started as a valve spring and rocker arm replacement project has turned into that plus pulling both motors, valve jobs on 4 cylinder heads and brand new exhaust.

Back to the topic of the thread. In tearing down the engine, I found this rocker.

[ATTACH=CONFIG]534545[/ATTACH]

Note the wear on the inner part of the rocker near the trunnion. This is caused by that nice stock spring's not being able to control the valve movement properly and the rocker's moving side to side rubbing against the poly lock. This is from a stock motor with 220 hours on it. Only a matter of time before this rocker explodes and shoots needle bearings everywhere.

That sucks man!!

Wonder if the valve seats are getting pounded from lack of spring pressure.

I had some crane rockers that were showing similar wear to the body like that. The rockers themselves felt fine with no excessive play. I was scratching my head. Then I noticed with the rocker installed and valve in closed position, there seemed to be a lot of side to side play. I happened to measure the polylock. Mine were .550 diameter. Looked up what polylocks go with the crane rocker, and called for .600 polylocks. Ordered a set of those and it eliminated the excessive play. The polylocks I had came with the engines and I simply never though to check that. You'll see on the crane rocker trunnion, they are machined in a way that the nut needs to fit snugly. Mine are not merc engines, but just thought I'd share that info.

Good luck with your rebuilds!

this could also be caused by stud deflection at RPM, ck with Bob M. as they have placed camera's under the valve covers and run on a dyno...results were scary of what they saw...

Eddie Young said mine looked like that when he tore down my 575's a couple of months ago. He didn't send me any pictures, but based on the track record - I expected him to find that.

Mine are getting a all new valve train as well. Also found some cracked leaking tail pipes. All headers are good. Just another thing to babysit on these motors. Starting to feel bad for you hyfive, I would of set my boat on fire by now if I had all the problems you've had.

[ATTACH=CONFIG]534548[/ATTACH]
This is what a cracked tail pipe looks like for those of you that don't know