525EFI Valve Springs Concerns
12-07-2014, 10:43 AM
#31
Platinum Member
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
Thanks
12-07-2014, 10:53 AM
#32
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iTrader: (6)
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.
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.
12-07-2014, 11:53 AM
#33
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.
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]
Last edited by HyFive578; 12-07-2014 at 01:42 PM.
12-07-2014, 01:45 PM
#34
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iTrader: (6)
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.
12-18-2014, 06:31 AM
#35
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.
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.
12-18-2014, 06:47 AM
#36
Registered
iTrader: (3)
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!
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!
12-18-2014, 08:35 AM
#37
Registered
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.
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.
12-18-2014, 08:46 AM
#38
Registered
iTrader: (1)
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.
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.
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.
12-18-2014, 09:15 AM
#39
Registered
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.
