Engine will not start 525 sc
 

I am running 525 scs. Just received the boat on Sat and it ran great Sat and Sunday. I went to go out Tues and started having problems. Motor started initially and then stalled when we where leaving the dock. I was able to restart with much difficulty and return to the dock. It started with much difficulty but would not stay running. Did not spit or sputter, just would not start. I am now unable to restart. Heres what I have eliminated so far.
New plugs, because I fouled the old ones trying to start.
New distibutor sensor.
Swapped distributor caps, rotors, amplifier(?), coils, and the new sensor, just to be sure.
New fuel seperator, did not appear to be any water in it.
Checked front float, no hole.
I am getting fuel to the carb (pulled line and pumped fuel into can), and am getting fuel when I pump the throttle, I also have 8# of pressure according to the gauge.
Electric fuel pump is brand new.
That said I am not sure what I am overlooking.
I have put a charge on the battery as I ran it down trying to start it.

Other motor fires up on first try. Engines have about 300 hours on it and where recently serviced.
Any suggestions ideas would be greatly appreciated

Does it have a choke is it open all the way

No chokes.

Are you sure you are getting spark to plugs,

Weak spark with the battery low on charge.

Has to be electrical are you sure distributor did not move clamp not tight?

Clamps tight. Rotor is spinning. No misifiring. Seems to be spark related to me, but not sure what to check now.

After turning it over for about 15 sec or so pull a plug. It will be wet if you are getting fuel into cylinder. They probalby are. If plugs were firing at all it'd sputter some.
Does all cylinders sound even compression when turning over? I agree it sounds electrical/ignition related.

I did pull 1 plug, it appears to be getting fuel. Its not spittering or sputtering at all, although that would be exciting.

You have checked everything that I would have checked.
I would check the wiring harness that plugs into the ignition module for corrosion. Also make sure the ground for the module and module and module case are good.
I had a similar issue with my 525SC and it was the coil.
I would agree that it is most likely ignition related.
Do you have 1 kill switch or 2???

I had a few times when mine got flooded and was hard start. Try holding the throttle at WFO when trying to start it.

what ignitions are you running ?

I had 2 boats do the same but it was two
differant problems, one was the comoutor
and the other was a very cheap fix. It was
the kill switch over the key, wasnt being held
in enough buy the plastic clip.

I am running thunderbolt IVs, I only have one kill switch, I have twelve volts at the + side of coil. Thanks for the help so far. I will check the wire harness for corrosion.

No corrosion, that would be too easy I am running out of ideas. Any suggestions? Thanks so much.

It sounds like you are extremely rich. Can't remember if the 525 carbs have power valves but mine go bad from time to time and leak fuel into the intake and the motor won't run or stumbles/loads up. Check the carb when running/cranking over and make sure you can not see fuel coming from the main jets, etc. You shouldn't be able to see any fuel with the throttle blades closed. Don't stick your nose in too far in case of backfire. If you got it to start after much difficulty the plugs are firing.

Oh also needle and seat could be stuck.

Missed that comment. So, after you got back to the dock no fire whatsoever???

,,,,

Where is your ignition module mounted?????

The troubleshooting guuide in c deezy's is a good start. A weak or bad ground on the module or module case will end with the "replace Ign module" also though.

Thanks for the manual. I have spark, its just really weak. Manual helps quite a bit. Lets see what I can find out. Thanks again.

Yeah I meant to add that as well. Check and double check all of your grounds. Give them a little tug too, they make look like they are connected good but could be loose in the lug.

Thanks for all your help. turns out that there is an overspeed assembly ( rev limiter) installed in the wiring harness, swapped them and the engine started immediately.. YEEHA! Bad news is its a $600 special order part. I am going to attempt bypassing it until the new part comes in.

Somebody probably has one of those used laying around. It is the same rev limiter/overspeed assembly that was used on the carbed HP500's. Many people switch to MSD's and get rid of them. I've never even heard of one of them going bad.

For $600, I would seriously consider switching to MSD's.

I had that exact same thing go bad a couple weeks ago. But for some reason, only one of the motors had the rev limiter so I moved it to the other motor and the problem followed.

If you want, you can just modify the harness to work without the rev limiter. That's what I did and it works fine. I can get you a pic tomorrow evening if you would like.

Yes please a picture would be great. Snake Dance rides again!

I know i am 12 years late, but do you still have a picture of the bypass wiring?