525 SC Problems - Help!
 

Hi guys,

I bought a 1995 38 Special (Baja) about two weeks ago. When I went on the sea trial with the guy the boat ran great. I guess it has some sort of intermitten problem that is driving me crazy. The one engine will run great and just die at any given time and then not start agian. I first thought it was loss of fuel but when I checked the carb and it seems to be getting fuel just fine. I then started to check out the the ignition system but I'm kinda lost. To tell you the truth I'm a noob to boat engines and could use some advice. Oh, one more thing. The engine will start just fine after it sits for 10-15 minutes. It's so odd.

Chris

Re: 525 SC Problems - Help!
 

Sounds like a question in the tech section right now. Check out the coil.

Re: 525 SC Problems - Help!
 

sounds like a coil doesn't it. swap coils?

Re: 525 SC Problems - Help!
 

Yeah, I took the coil from the other engine and the problem didn't follow... I also replaced the pick up sensor on the distributor. That gave my engine about 2-300 more rpm (odd)than before but no fix on the stalling-

Re: 525 SC Problems - Help!
 

yes, sounds most likley the coil next time it happens feel the coil if hot thats your problem or you can try just swapping them as suggested.....you can do a resistance test but this is easier

Re: 525 SC Problems - Help!
 

Watch the tach very carefully when it fails. If the tach drops VERY quickly or wobbles before the engine dies you likely have a bad ignition module. They will overheat internally and stop sending signal to the coil. Takes about 10-15 minutes to cool down and away you go. :D

Re: 525 SC Problems - Help!
 

When I watched the tach the needle "bobbed" like the engine was running out of gas or something. It would try to go back up a couple times then after that the engine goes dead -

Re: 525 SC Problems - Help!
 

Swap the module or put in a new one, they're cheap.

Re: 525 SC Problems - Help!
 

Awesome - Is that the blue looking box near the dist? It is called Mercathode or something?

Re: 525 SC Problems - Help!
 

Whoops, I take that back, I just looked it up. That sucker is expensive, swap them first to see if it's the problem.


An newer module will look like this one

And an older one looks like this

Re: 525 SC Problems - Help!
 

I would check your fuel supply again. If you have a stock fuel pump set up it is run from a small cam which is part of the sea water pump assembly. If you unbolt the fuel pump there should be gear lube in there. If you find water and or fuel and the cam and lever on the fuel pump are worn that could be your problem. I have three of the same vintage and they all needed to be replaced. Do you have fuel pressure guages?

Re: 525 SC Problems - Help!
 

sounds like a module failure to me.

Re: 525 SC Problems - Help!
 

Try what Cool Trips suggested. I have seen that same problem and symptoms your having.

I just purchased a 42 Lightning with triple 525SC's and am having the same problem on my center motor. It will start up and run fine but as soon as I try to run the motors above 3.5K the center motor will start to die. Right before it dies the tach will dance around between 0 and 1,500 RPM a few times and then just fall to zero. After the motor sits for a few moments it will show signs of life but die. This last weekend at the lake it only restarted after the other two motors were running and we were headed back to the ramp. I then tried to take it for a quick cruise to cool off and get some time on the water so I kept the motors RPMs under 3K and it ran ok for a few moments.....until it stared to overheat due to a hose that came off the oil cooler. The last mechanic that worked on the boat must have forgotten to tighten the hose clamp....because it's not there any more.

Can anyone verify that this problem has been typically related to the ignition module? The carb was always full of fuel and running around 6PSI of fuel pressure, and during some brief diagnosis time spark was intermittent.

I purchased a new 1997 baja 212 islander with a 454 mag that had the same problem as you are describing. The thing would just shut off while flying across the lake and restart once I came to a stop. It turned out to be the main wiring harness from the ignition switch causing the problem. They replaced the harness and solved the problem. I would monitor power to the coil while running to see if you are losing power from the ignition switch.It may also be a ground issue somewhere with the ignition system.

x2 heats up and bang you are dead in the water cools down comes back! See it all the time on cars...... Check for spark next time it dies i am sure you will have zero!

We did and it would come and go. I just wanted some more feedback before I order a $350.00 module.

fixx
 

common problems are ,,the hall effect in the distributor,my friends tach would bounce then die,,replaced the 50 dollar part and took care of it..

same problem on another friends boat and it turned out to be the alternator back feedint a/c power into the module and causing it to get hot and die,then would restart after it cooled off..oreplaced the alternator and it took care of that problem..alt was putting out between 16-19 volts..

You should start the suspect engine and while idling giggle every purple primary ignition wire you can find. They go to the coil, kill switches, ignition switch, alternator and module. Also giggle the ground coming out of the module and the connector into the module. If you can get it to do it again, you found the culprit.

I had an jumper wire with me when out on the lake and wired the coil directly to the battery and still had no spark. The thing that gets me is it would fire up for a split second and then die followed by no spark again for 4-5 minuets. And then it started up and ran just fine once the SBD and Port motors were running. I pulled the module and revlimiter today and from the outside they both appear to be ok, but that is just a visual inspection.

Does anyone have the 525SC tech manual flow chart for checking out the ignition system on this motor?

If one of the purple wires is shorting to ground it will short out your jumper wire too. Do the giggle test. My first areas to giggle would be the wire between the harness plug and alt and the ignition/kill switch area.

Moving wires around does nothing. It's only when the motor has a load on it above 3,500 RPM will the problem resurface. This problem cannot be duplicated on the hose.

Go out and run it again till it does the no spark thing. Then giggle the wires. See if you get spark again. One ign wire is shorting to ground probably when it or the surface gets hot. That or the dist or module ground is weak.

Don't GIGGLE the wires. JIGGLE them..:evilb::lolhit:

I DID THIS WHEN I HAD NO SPARK AND THE MOTOR WAS HOT!!! I don't know how much more clear I can make this point to you. The problem is not in the wiring. Screw it I'll just spend the cash and replace parts. Thanks for the help...not so much.

Please remind me to never try to help you again with my experience of problem I've already had and solved. Your an ungrateful asshat.

Giggle, thats funny. :o)

wow,a pizzing contest about advice.to the origional poster,i had a 96 baja with a pair of sc525s,the port engine developed the same simptoms you are having,the problem was the hall efect unit in the distributor,i did some research and found that it was a common problem,this is what i would change,worked for me.

I got a hold of a diagnostic flow chart and found that the sensor in the distributor was the problem.....not loose wires. :-P now I just need to replace the elegid defected pickup and see if it runs.

fixx
 

when you get the new one make sure its the updated one..i for get what the diffewrance is,but it is almost a totallly sealed unit and i think it has wires attached to it..

You would be far better off to pull and toss the POS Thunderbolt ignition system and replace it with a complete MSD system.

I would definately disagree. The TB is far more reliable than a MSD and unless you need an MSD for incresed spark or tunability options, there is no reason to spend the $800+. Plenty of TB ignitions out there the 15+ years old. I doubt the same can be said for MSD's.

I agree I know a guy that switched to MSD a few years ago, everytime he turned around he was fixing problems with it.. He finally took it all out and put the TB ignition back in and, since he did that he has been running without problems!!

Is that why there called [ Must Soon Die ]

I know there are PROS and CONS for everything, but I have ben running MSD ignitions for years and I cant count the number of MSD ignitions that I have installed in other people's boat with the same problems as mentioned...and none of them have ever had an issue. All the ignition problems were solved and some were installed back in the mid 90's. With the MSD distributor, I put the black bushing in giving 20* advance in the distributor and then 12* or 14* on the crank, making a total advance of 32* or 34* at 2500 rpm. My question then is how do you get the advance out of the Thunder Bolt past the ECM to get a decent advance timing when one installs a better cam or parts in the motor? With a MSD system...all that ECM stuff goes away and if you have to have a rev-limiter, then you can put a chip in the ignition box. If you look at alot of the pics of the big Pro-engine builders, you will almost always see MSD ignitions on them. I dont see the PRO's using MSD ignitions if they all give problems.

Precsion.... was that you on Clinton on Saturday? I seen you guys had the wrenches turning on it. Nothing like going to the lake trying to enjoy the day and having to get the socket sets out.

Yeah that was me. I had actually went out just to try to duplicate the problem again so the wrenching was totally expected. The good news is I was able to properly diagnose the problem and now the motor is running. Althought it would have been nice to run around with everyone I was just glad to get the it diagnosed.

Last thing that I need to worry about is the port motor has a potential fuel pressure problem. After running for a few moments the pressure drops to around 4-5 psi, and when the motor retuned to idle the fuel pressure gauge reads erratically for about five minutes. After that it reads normal again. I'm going to swap sending units but I'm afraid that the check balls in the fuel pump are sticking.