Engine help
 

I need a little help with a problem with my 525 efis with around 90 hours, in my 2005 42' EX. When I bought the boat we had to have the port motor top end rebuilt due to a bad #8 cylinder. The piston was damaged and the cylinder walls were scored. Never did find a definite answer to what caused the problem. Tested everything including the injectors, pressure tested the CMI headers, no obvious problems. Might have been caused by reversion?
Now the starboard engine #8 cylinder has the same problem. Damaged piston and definite water reversion. We did find a broken/cracked ceramic on the spark plug on this one. Maybe was not firing and sucked some water back. You can see a definite water track from the header port into the exhaust port on the head. Any ideas from anyone with similar problems?

Did you have the C.M.I exhaust pressure tested? Heard there was a weld problem in 05.

That's just what I was thinking, check the headers. Good luck.

Not just in 05 but every year they were made. They're terrible!! Def check the headers!! They leak all the time.

Headers, they all leak at the rear cylinders, some only leak warm and will really fool you.

Didn't think about them being warm and expanding and leaking. Makes sense, the mechanic pressure checked the set on the first engine before they put it back together. We had planned on checking these, too. If they leak when they are warm, then there really is no way to tell if the pressure test is okay.

did it break when you where comming down on the throttles??

I don't know when it broke. Never a problem, everything was normal, no lack of power. After we got back from the casino trip, my son who is a Harley mechanic was helping me clean it and flush the engines and while the hatch was open he said that the engine had a knocking noise in it. Sounded like it was coming from the back of the motor, and was not too loud. We went out the next day and when it was under a load you could tell it was worse. Cleaned the boat up again, flushed the motors and brought it over to CLPBS.

Do all headers exhibit this problem or just CMIs? I was thinking - do the Stellings have the same problems?

does not sound like the headers to me

I had same problem with cmi's and silent choice on rear cylinder(s). My engine man claims the water got injested when starting the boat on silent choice, and was adamant that it be eliminated on any motor that has radical camshafts. I'm eliminating the silent choice per his instructions, when the motors are finished, but can't tell you yet if that is fact or myth.

I would think you could warm them up with a torch while they were under pressure and see if that changes anything. If I'm not mistaken here, most claim the leaks are at the flange where the pipes are welded up. Seems like that area would be fairly easy to heat up. Does your boat have the silent choice option?

I really interested in this, seems like it pops up all the time in relation to the 525's with the CMI swept back style headders. I'm shopping for my next Fountain now and everything I'm looking at is in the '04 to '06 range and has the 525's. Hate the thought of having to deal with this after spending 150 - 200K on a boat. Anyone know if it is for sure the headders or is it the silent choice???

I don't have silent choice on this boat. The 525's do have a fairly radical cam though. I did have a broken/ cracked spark plug on that cylinder. If it does not fire, could the cylinder suck water back.

Does anyone know if there is a better set up for the exhaust tips than those cheap flappers to prevent any water coming back through the tips when coming off from plane or backing up.

In our area where Gerrit and I boat, here is what has happened this boating season with 525 efi's built around 2005 time frame.
1. I lost 2 engines where valves stuck and popped the piston at 112 hours. Issues started at 90 hours though.
2. 1 Formula lost 1 engine at 130 hours.
3. 1 Formula lost 1 engine at 75 hours.
4. Gerrit has lost both engines at about 90 hours.

None of the above came up with a clear cut answer as to why. My headers do not leak. My repairs consisted of increasing valve guide to stem clearance, upgrade to Crane severe duty lifters, and removal of Corsa Capt. Call exhaust. There is something going wrong with 525 efi's in our area but after I spent 15 weeks of downtime researching, did not get a decent answer for any involved (Merc. Racing, Corsa, Boat builder, etc.). After several thousand spent, I'm just hoping it doesn't re-occur!

I have only had to fix a pinhole leak on one of the STBD header tubes on my STBD engine with no actual engine issues as of yet. The header was sent back to CMI who fixed it and supposedly pressure tested it before sending it back. I am following this thread with interest.

I had a similar problem with my CMI's, the weld by the flange. Hair line cracks where the pipes were welded to flange. Found them when I put them under pressure with a hose. I took them to a local welding shop, we heated the pipes and they expanded to show the cracks and had them grind off old weld and then re-weld. Seemed to be alot "thicker" weld than from the factory. Cost me $90.00 and seems to be holding fine. Just my .02....

I would think that it could suck water back, in the absence of any combustion there would not be the normal cylinder / exhaust pressure, might well let it pull water back.

There are thru hull tips that have an internal flapper/baffle set inside the pipe itself. You also run the external flapper with these and that gives you somewhat double the protection. The other option would be the Drew Marine Shotgun Silencers, they also act as a baffle/flapper, On my Velocity I ran the internal baffles combined with the Shotgun silencers.

I really don't understand the CMI problem, I had the CMI Elbow Tops on my 525 SC's in the Velocity, put them on in 1997, sold the boat three years ago and the guy is still running them, neither of us have ever had any issues. I was fresh water only, but he runs salt water some. That's ten seasons of use, admittedly our season is shorter up here, but still it's a long time.

Question here........... are all these failures at the #8 or #7 cylinders???

Are the 525's normal BBC firing order??

Tom

As for as I know, and I have to talked to some of these guys, all are stock non-modified 525's. We are developing a picture that might have to do with the type of water, fresh vs. salt, but we need more information. Seems few of the failures come from fresh water users.

you have any pics of the broken parts? head, piston, ect...ect...What did your internal flapper look like on your exhaust tip?

I don't have the piston out of this engine, yet. The heads and valves look normal and the damaged piston in this starboard motor has a similar chunk out of it. Here are pix of the damaged piston out of the port motors. I will have to check the internal flappers on the tips, far as I can tell everything looked fine. Notice the 2 chunks out of the edge. Never did find a defintie answer to this damage. The boat ran 83 mph with no signs of a problem and no noise on Lake Michigan when we test drove it. The only way we found this damage was by a compression and leak down test.

I was told by Merc. Racing that the 525 efi is the most susceptible engine they build for water reversion issues. The blowers motors do well because of the increased exhaust flow. Therefore, when any mild issue such as spark, fuel, injector, header leak, increased back pressure, etc., occurs, problems start to happen. I think in our area, the issues surface quickly due to the warmer water with added salt conditions. I was running the external and internal flappers when mine failed so I don't think this is a cause or resolution. Hope all of our failures down here are just isolated cases. ps: My 15 weeks of downtime research file is too thick to post here. We beat up all lot of possibilites that could have caused this. However, as consumers, I found it to be very difficult to get info. from the engine mfg. or exhaust folks. You can see where my #8 cylinder exh. valve struck the piston in pic. Good luck!

Why would they be any more susceptible to reversion issues than the 525SC, 575, 600's etc. I thought they were all based on the same 502 GM block? Is it the cam lope? Slow idle? Maybe that would be an excuse for blowers?

It was explained to me by an engineer. I'm sure folks on here can explain better than me. But, it has to do mainly with idle. Blower motors normally have less compression inside the cylinder than normally aspirated (efi, carb, etc.) engines so when the boost begins to kick in, you're not over compressing the cylinders where head gaskets would blow, etc. (the 525SC was 7.5:1 where the stock 454 was 9:1) The 496 HO doesn't quite have such an agressive cam profile, so doesn't create as much water reversion potential. You are making more than 1 hp per cubic inch in the 525 efi. One of my earlier boats had a 330 hp 454. I installed a cam, intake, ignition, etc. and it dynoed at 424 hp with all the performance increase parts. The 525 hp is derived from 502 cubic inches. It is a very radical internal set up even though it idles very well. The cam is probably as far as it can be taken and stay just on the edge of not creating water reversion with the CMI's in "new" condition from the factory. I think 75 to 130 hours is creating wear issues on something and that's all it takes to get the reversion or engine failure in warm salt water.

Problem is not limited to 525's as mine are 555's on carburetors with cams with lots of lift, duration and overlap. I think the silent choice just compounds the problem as the water is able to come in through the lower units whereas it has less opportunity to get through at the transom, but as has been attested it can get there through the transom as well. I'm going back with milder camshafts with less overlap and duration and eliminating the silent choice for my own piece of mind but haven't a clue other than the engine builders word that I won't have further problems. I don't know what the cam specs are on the 525's but I would suspicion similar high lift, high duration, and substantial overlap that helps the motors get the performance they enjoy, also help with reversion if water comes back through the headers when the exhaust valve is open, and it doesn't have to be running for an exhaust valve to be open.

I had a similar problem with my headers, a pinhole leak where the 4 pipes meet at the collector. (an easy fix) But I bought another fresh set just because... I run in salt all the time, so I flush with salt away and when I'm done, I unscrew the draincocks and drain the headers as well, so they stay dry when stored. A little over 40 hours on them and no problems since.

headers
 

I had the same problem on a customers 2001 42 with 525's. The port engine outside pipe started leaking by the mounting flange. I talked with a rep at cmi and they told me this was a problem they had and was caused when the headers were welded and they had since changed the design. I ordered a completely new pipe and it was a little different near the flange. The cmi rep told me they were aware of the problem but would not warranty anything. I heard this guy just lost the starboard motor to the same problem.

I know 3 of the 4 boats down here are not CMI related. Don't know yet about Gerrit's.

Tommy, I spoke with Norm and he said the exhaust valve guides were leaking on his engines and that is why they failed? I don't think anything in his conversation implicated the exhaust system. As you know I also have 525/CMI units in my 42 and knock on wood so far so good, saw an easy 83 mph in Conroe yesterday with the props just back from Mike Hood propshop, and just ran great. But we have been in fresh water all summer. Fixing to bring the boat back to Seabrook for the winter when the water comes back.


So lets itemize the facts here as much as we can. Do we KNOW that the CMI's are a factor? What exactly has been proven? You had bad lifters, right? Whats funny is all these failures happen on both engines at about the same time.

I have one of the newer 525´s (built April 2006) with nearly 160 hours on it, driven hard and fast. I do not have silent choice, but internal flappers, and run clamp on CMI Sound Eliminator mufflers sometimes.

No problems so far from the power unit, although a reoccuring problem (at around 30 hours) with the water supply (s-hose between xr and transom) caused the guardian to chime in and stop the fun when running at full throttle a number of times. This caused the CMI´s to get heated up and turn brown. Once I had found the solution, which was simply to to put some silicon grease onto the s-hose and the belows, there was no further sign of any issues. The water pressure spikes and dips that are experienced when running a relatively small hull at WOT in big waves, were causing the hose to jump as it expanded and contracted under pressure!
The CMI´s polished up good, and the last 100+ hours have shown up no weaknesses at all.

What I´m saying is that I´m impressed with how robust both the motor and the headers have been up until now.

The raunchy sounding idle (created by the hot cam profile) does sound like it is just asking to suck water back into a cylinder, though.

Andy,

As per my reply, I said I don't think the problem on 3 of the 4 boats down here was CMI related (in regard to leaking headers). I had 3 potential failure causing issues, not just the lifters. Capt. Call, lifters, and valve guide clearance. Anyone one or a combo of all could have caused my issues. I do know that Norman did change to the Crane severe duty lifters though (like I did). I compared the old to the new, and the Crane looked like a much better lifter. All of the 525's I know about were built in 2005. Just wondering if anything changed during this timeframe on internal parts? Maybe some engine folks on here may have looked at the internals of 2004 and 2005 525 and can provide some feedback.

Tommy

Thanks, Wild Card, I remember when you put that engine in your boat. Do you go more in fresh or salt water? And if salt what is your flush procedure? What speeds do you get with a 25 ' hull?

Tommy, I have 2005 525's as my boat was put into service 3/4/05. Merc racing says rebuild/refresh on them averages at 6-800 hrs, so they are "good, long lasting motors when they are not abused", whatever that means. He said the '04 and '05 motors were essentially identical.

Port motor update
 

We got the boat back Friday. Here are some pictures of the damaged piston from the #8 cylinder. Also a side by side with the damaged piston from the #8 cylinder on the port motor. Ed, Darrell, and Brent from Clear Lake Power Boat did a great job. Did a sea trial and the boat runs better than ever. We didn't push it too hard, but it has all of the power and performance back.

Here is what we found. Pressure tested the CMI headers and no apparent leaks. #8 had a cracked spark plug. The mechanical fuel pump was bad. Tested the injectors and all were within flow specs. Found some signs of reversion in the #8 header port. Found 2 missing internal flappers on the exhaust tips, but the one from the #8 cylinder was intact. We replaced all of the exhaust tips with new ones with internal and external flappers. Completely rebuilt the top end of the motor. Pistons, rings, valve job, etc.

No defintite smoking gun as to what caused the piston detonation. Did one of the above problems cause a reversion issue or did a reversion issue cause the problem? Your guess is as good as anybodys. I just hope this is the end of these issues for a while. Good to know that I have 2, basically rebuilt motors. The bank book is a little lighter now. We are glad to have " Perfect Timing " back.

I would think the bad flappers did not help at all.....:(

Good to hear your going again

Thanks for your reply Gerrit. Can't wait to see you out again.

Want to know something interesting? My boat was put in service 3/4/05 and it has the new style "cool collar" CMI headers on the port engine and the old style welded-at-the-flange headers on the STB engine!!

It appears the problom is a combination of factors.Some of the candidates that create reversion> Cam profile, to low of an engine idle, stationary idleing, exhaust pipe geometry and exhaust design. I am skeptical about all the talk about valve guide issues and even faulty lifters. When a specific
fault can not be determined you will find that everything gets placed on the table. Also some piston failures are due to hot spots around the cylinders and detonation. The former caused by a cooling sys prob within the block and generally takes time to take its toll. I am also becoming concerned about fuel blends? We are already seeing how the change in fuel blends is negatively affecting automotive components.

I agree with you, Frank. The biggest sticking point for me is that EVERYBODY, without exception, had both their engines fail either at exactly the same time, or very short time between. What factors affect BOTH engines at the same time? And it also seems to be worse in salt water. We have been in fresh all summer without incident, and I called the biggest Fountain/Formula fresh water dealers I could find in Austin, Havasu, Texoma and Great Lakes and nobody sounded like they had what we have going on. So I wonder what "combination of factors" is leading to all the trouble?

Andy:
Their is no doubt that with a more aggressive cam like we find in the 525s the sequence between exhaust pulses can allow for a diff pressure that can facilitate flow reversion.This coupled with the other stated factors causes the problom.
Now, once the water enters the engine and depending
on the quantity the dynamic changes. The salt water variable remains unclear other than pure coincidence. If the tipping point is header-metallurgy related than the corrosion factor of salt water becomes a compelling subject. With that being said their are cases of these probloms in fresh water enviros. In your case you may be lucky, at least up to now. Things as simple as the attitued of the boat in the sling or the trailer can let water flow into the engine. As I said
earlier fuel blends are becoming a player in engine probs>> IE detonation. Knock sensors should pick it up and momentarily retard timing, if eng mgt is working? Ethanol is creeping more and more into the blend, not to mention what is being removed. Phase seperation is going to be an issue not to mention the sulpher changes in diesel fuel. Low sulpher in diesel translates into less energy (lower power) and less lubricating abilty to pump and injector internals.
never fear>> its nothing money can't fix.

Frank

Frank, we ran all of the codes in the ECM's on both engines and there was nothing unusual. Just some random stuff. No knock sensor codes or anything that showed the engine had malfunctioned. I am beginning to think it may be a fuel issue. Although we ran our boat almost every weekend and bought the fuel from the same place, I am wondering if this fuel is just poor quality.

Gerrit

Knock sensors will not set a history code unless thay have failed. By the look of your pistons it appears that the scoring may have been do to irregular heating. Normaly when we see detonation damge due to uneven combustion over the top of the piston we see actual physical damge across the top of the piston before it takes out the side or ring area. The problom is more prevalent on cast then forged pistons. I think the 555 marine pcm has the capabilty to look at spark advance per each cyl and how it relates throughout the power curve, providing you have the diagnostic software. Take a good look at *CYL IN-LIENMENT> IE>injector pulswidth which is the amplitude and the duration of the injector or how long between on and off. Is the injector spary pattern what it should be? It should be conical in shape. Check for the right fuel pressure and the right fuel trim. Fuel trim is set by the PCM and is always changing. all these factors can be undetecbale by the boat operator but can lead to piston failure. Both the auto and marine indystries are very concerned on how FUEL BLEND CHANGES are going to affect their non FLEX-FUEL engines and fuel systems. And like I said prior>detonation in todays cars is becomeing a bigger and bigger problom even when the fuel mgt sys is working. Now we are seeing the same thing in marine engines