Engine Stops after 30-40 mins
Hi All
I am new to the forum and I have C&C 34 1978 boat with the A4 engine with the crank handle on the front of the motor. I can start the engine on the first time and it runs very well for 30-40 mins then it starts struggling and if try to increase the speed it doesn’t like it, if I lower the speed it slows but still struggles shortly after stops. I have replaced the fuel / water separator filter and the fuel pump. I removed the fuel from the old filter and gas looked great, the temperature gauge needle is showing between 140 - 160. But my problem is still exactly the same. |
Welcome to the forum and welcome to A4 troubleshooting. I have a two-tiered test for you to perform based on your report:
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Reporting back on tests
Removed gas cap and ran engine in gear at 1460 rpm it ran for 52 mins in total.
It started struggling at min 33 to 52 During the run water temp was 178 , consistent white vapour it had smell and was warm to the touch and lots of water through exhaust, oil pressure steady at 40 to 42. Not sure if I performed the spark test correctly, never done one before. Engine stopped I push in my ignition switch ( other wise my points burn out I am told) I went under the stair hatch pull lead off the 1st plug in front of the row removed the very hot plug attached the lead cap to it and cranked the engine handle anti clockwise or to the left I did not see any spark crank 3 or 4 times total. The spark plug had some black residue on it, I haven’t checked the rest of the spark plugs. |
Negatory - - the engine must be cranked the same as trying to start, ignition on, starter turning. The hot spark plug suggests you have spark however meaning this is probably a fuel related problem.
Practice doing the spark test anyway so when you do it for real you'll know how and know what to expect. |
Rerun of problem
I will re run the tests today and post results thanks for info on spark test I wasn’t sure how to do it
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I suggest doing the spark test as you start the engine for practice then again immediately upon shutdown. You'll probably need a helper to operate the starter while you observe for spark.
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https://www.harborfreight.com/12-vol...iABEgL8SfD_BwE |
Results of second test run
This time I left on the gas cap and the engine run was 1 h and 2mins and it only started to struggled in the last few mins of the run .
I performed the spark test with ignition on and got a blue spark. Any thoughts on what I could try next? |
JXP, you stated the plug had a black residue. This leads me to think you are just to rich and after a while (updraft carb!) the engine just floods out. Once it sits the excess fuel evaporates out of the engine and repeat.
Check all 4 plugs and if they are black or sooty check to see that the choke is fully open. If an open choke is confirmed you have a carb problem. Your blue spark and dirty plugs lead me to this. When you were running the engine at 1450 were you in gear or not? Dave Neptune :cool: |
When the engine starts to "struggle" shut it down and put finger on the stuffing box.The stuffing box should be close to the water temperature the boat is floating in.
TRUE GRIT |
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Changed the coil
Engine run in gear for 30 mins sputtering and I tried the choke as per manual. It didn’t change with a bit of choke. So I checked the fuel tank pickup tube and blew it out but nothing came out and the screen was clean.
Next I changed the coil, and re-ran the engine in gear it ran perfectly for 2h 36m, I thought i found the problem, then the engine suddenly stopped. Back to the drawing board. |
do you have points or electronic ignition?
Peter |
I have points
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ANOTHER TACK
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Here is another thought.
This is a quote from Don... "There is at least one other item that behaves in this manner (fails from heat and cures itself when it cools), which is a faulty connection in the primary ignition circuit (some electricians call these faulty connections cold joints, I suspect because they only work when they're cold). Please skip this paragraph if this is more than you wanted to know, but I am told by normally reliable experts that an electrical circuit sees a weak connection on the verge of failure as a localized zone of high resistance which translates into a small amount of heat build-up. As the heat builds up, the expansion created by the heat eventually causes the connection to open up (minuscule though this heat and expansion is, remember that a connection in this condition is on the virtual edge of failing anyway, even without the heat and expansion). To keep things simple, before chasing the entire primary circuit which runs from the large battery terminal on the starter solenoid, through the ignition switch and back to the positive terminal of the coil, you could simply connect a jumper wire from the large battery terminal on the starter solenoid to the positive terminal of the coil. If the engine never shuts down as long as that jumper wire is installed, you will have confirmed that the primary ignition circuit is a cold joint in it someplace. If the shutdowns continue with the jumper wire installed, you can check the remaining short section of the primary circuit which is between the negative terminal of the coil and the points. Sometimes the conductor in this short wire develops a cold joint where it passes under the distributor cap or at the terminal of the coil or at the points themselves." IMPORTANT NOTE: Installing the jumper wire between the starter solenoid and the coil is the very same thing as turning on the ignition switch, so you cannot leave that wire installed except when running the engine or you willburn out the coil or kill the batteries. :eek: You can read the entire post and thread here... |
An interesting side note...
If you do read the entire thread, note that the main theme is hot and failing coils. :rolleyes: Especially in POSTS #3 and #14 Seems the forum was trying to figure out the Rule of 2011 back then too! |
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How do I do this - what gauge of wire and do I wrap it around the bolt on the solenoid and + on the coil. Then do I turn on battery one and pull out the ignition swtich press the starter button as normal and see how long it runs for - then when it doesn’t stop .... stop it by turning off the battery remove the jump wire ? |
Ignition switch
My ignition switch is also playing up sometimes I pull it out and press the starter button and the engine doesn’t start, then I push the ignition switch back in and pull it out again and press the starter button and it starts the engine, I will replace it, is there a post on how to do it?
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Sorry to leave you hanging there. (Work got in the way yesterday :cool: ) Connect a jumper wire (12-14 gauge) between the large battery terminal on the starter solenoid and the positive terminal (+) of the coil. Alligator clips make this easiest. (Remember this is temporary) Connecting this wire is the same as turning on the ignition switch and it will by-pass any problem that may exist in the "starting circuit", including the ignition switch itself. DON'T leave the jumper wire installed very long unless the engine is running or you'll pretty likely burn out the coil. It's the same as having the ignition switch left ON Quote:
Not good for the Alternator. (There are many posts here on the forum about this. We can dive into that later) Just remove the jumper if you want to turn off the engine. GUYS - Jump in here with advice if I'm missing something. |
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Hold the phone... I apologize but I may be taking you down the wrong rabbit hole. I just re-read your earlier posts and the engine sputtering symptoms actually point away from an ignition issue. Now, you may still want to replace that wiring and switch but let's do only one issue at a time. Quote:
Please follow Dave's advice (Post #9) especially verifying your choke is opening and closing and then report back. Again, sorry for leading you astray there. ADMIN BILL - I'll leave the previous posts so JXP still has the instructions and the string in the thread makes sense in the future. Unless, of course, you feel otherwise. -j |
Jerry, No need to apologize. Actually, adding a direct route wire from a good source (battery) to the coil, is an easy thing to do and it will get the ignition switch and wiring out of the equation. The one thing that I would add, is that if there is a resistor in the coil circuit, that's where the +12 volts should be connected. The delux version of this added wire would have a toggle switch in line.
Tom |
Update on my progress as of 13 Jul
When I changed the coil, the problem changed. The engine is longer sputtering at all.
It ran in gear for an amazingly 2 hours and 36 mins, then it stopped abruptly - as if I had push my ignition switch in. Today the 13 jul I installed a new ignition switch, I am going to try and run the engine again to see if I can run it longer without getting and abrupt stop. I will report back on my results. Could just say thank you to all my contributors I am a newbie beginner and I appreciate all of your support. Thks Jen |
JXP - you have a point set up with a later model engine [delco distributor] - I think your current gap setting at "top dead center" would be noteworthy, also brand and model of coil ie resistance. There could be a "dwell" issue here relative to coil overheating and shutting down. Wrong coil could also cause the same heating problem. I would eliminate these two issues then change the condenser
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