Engine dies after warming up

[Supersport18]

The breaker tripping would lead me to believe you have a bad coil or ballast resistor. Shouldn't trip throttling up or down.

[thanksdad]

Question for Tranquilo. How did you rig your auxiliary tank for fuel testing? A friend is having a very similar stalling problem and we want to test fuel issues completely. fuel testing is always tricky so any thoughts would be great.

Also, how bad does fuel have to be before it should not be burned. I know this is a tough question, but most old/dirty fuel issues can be solved by adding fresh. clean filters and burn, burn burn, But there must be a limit to this. His fuel is pretty dirty, but not the worst I have seen. Thoughts?

Thanks, Scott

[ericinga]

I had the same issue last summer. The PO had cobbled up the components in the ignition system.

Based on your comments, the ignition module is overheating. You should be able to put your hand on the module at all times. It should be luke warm. Mine was scalding hot. I took the FastJeff approach and installed a Mallory high performance resistor and high output (42,000 volt) coil. Never had a problem since. My 39 year old motor starts faster and smoother than all my friends with newer boats.

Here's what I learned. (I'm going from memory).

If you're technically inclined, take the following steps:
1. Check the resistance across the ballast resistor. There are four posts. Test the resistance (ohms) across the two poles at a time. One set should read 0.5 ohms and the other should read 5.0 ohms. If this test is failed, replaced resistor.
2. Test ballast resistor voltage. Check voltage at the red wires into the resistor. It should be within 1 volt of battery. If this test is failed, replace resistor.
3. Verify voltage at the coil. Test the voltage into the coil. Put the positive lead on the coil and ground to the engine. The voltage should be within 1 volt of battery. If this test is failed, replace the ignition module.
4. Verify coil resistance. Connecting multi-meter to + and - on coil, the resistance should be 1.4 - 1.8 ohms. Then connect multi-meter to coil positive terminal and ground to engine. The reading should be 12K - 18K ohms. If this test is failed, replace the coil.

If you're not technically inclined, buy a new coil, ignition module and ballast resistor.
1. Replace all the components - OR -
2. Take a friend with you and run to failure. Replace components. Start with the ignition module.

Extra credit work:
- Verify the resistance of each spark plug wire. Each wire should measure a perfect circuit.
- Pull the distributor apart and lube the advance weights.
- Clean the rust from the reluctor (paddle wheel)
- Check the air gap between the reluctor and ignition pick-up coil.

At Auto Zone, the component part numbers are:

Stock ignition system:
Ignition Control Module: CR109 $24.00
Ballast Resistor: CR105 $4

FastJeff Approach:
Mallory 700 Ballast Resistor 700 : $25
Accel High Output Coil 8145 : $54

On Amazon.com, the cap and rotor are the following:
Cap - Wells AL950
Rotor - Wells AL937

I don't buy the Sierra ignition products. I've found the caps have tracking and bad springs. The rotors crack and fall apart.

If you get into the middle of the job and want some help, give me a call, 770-402-8897. After drifting in the middle of the Lake Lanier on a few ocassions, I can do most of this from memory. If you're in the Atlanta area, I can stop by and figure it out.

Eric

[bill]

Tranquilo wrote:
"Pretty bummed because I just painted it and drifted into a tug!"

Could you please put where your boating area is in your signature!

So far you have recieved alot of good advice. Now its just the process of elimination.
A little easier with twins

Just saying don't buy Sierra caps or rotors made in China. Wells are still made in the USA

Good Luck
bill

[Tranquilo]

Updated Sig! - I am a BIG made in the USA guy:)

The advice about the ignition system feels right in my mind (I was an electrical tech back in the day but all industrial equipment and planes)

My fear is a cracked head from the overheating incident last week. But since I never drove it before (just bought it), I have no historical reference.

I'm heading down there this afternoon to dig into the system with a mechanic I'm told is good.

Fingers crossed!

PS the fuel thing is super easy! Just get a new line and run it in place of the tank line, into a 2 gallon can. Keep the hatch open & don't smoke

[Tranquilo]

Eric - Thank you VERY much!

I may take you up on the call!

[ericinga]

Anytime. It's not like you can take a Marinette to a local shop and expect them to know the boat. I talked to my marina about our boat and the mechanic asked me if it was made of wood.

One thought on the dirty fuel tank. I had that problem. As a short term solution, I placed an in line filter before the spin on water seperator and one before the carb. It was cheaper to change out the $3 filter than a $20 filter. I changed it once a month for three months last summer. I ran the fuel tank down to 1/4 full to create sloshing and work out the gunk.

Now, I don't have any issues.

[Tranquilo]

OK - So it looks like the coil is bad per the readings. I'll order the parts tonight and install tomorrow.

I did notice something really alarming while running it today. My oil pressure is pegging at 80psi. It wasn't doing that before (was around 40psi the first ride before I lost the impeller) - I ran it till it died again but not sure I want to run it anymore till I figure out what the hell is causing that.

[Tranquilo]

I ordered my ignition parts today and will get them tomorrow for install.

I put a mechanical gage on the oil pressure sending unit spot and got 60psi at idle (700rpm) and 70psi at about 1500rmp

Its lower than my electronic gage but still a bit high as I expected it to idle at 30 to 40psi.

Is this a problem??

The engine has been sitting for about 6 years so I suspect sludge build up. I'm going to do an oil change and toss in some mystery oil to see if it fixed anything. The oil on the stick looks new but I have no faith in the previous owner to think he did anything other than top it off.

Any experience would be very helpful.

D