No compression

[Dave Neptune]

Marty, same plug but the "R" stands for a resistor plug a plus for the A-4. I always used the RJ12C which is a resistor style and marine grade with the copper core ie the "C".

Dave Neptune

[JOHN COOKSON]

Originally Posted by Quentin_D

After that, when we tried to start it, it ran pretty fast as if it almost started but then, after 20-30 seconds that we had begun to push the starter button, it brutally slowed down while we were still pushing on the starter button.
We tried 3-4 times and always the same behavior.
Do you think it is just because of the low battery or it can also comes from the ignition system ?NO THERE IS A THIRD ONE

Maybe this has been mentioned already.......
Have you checked the wiring? The end connectors need to be clean and bright and no corrosion of any kind in the wiring itself. This includes the battery terminals. Check both sides of the circuit - hot and ground side. The hot side will be a red wire ~ big around as your little finger. Maybe bigger. Check all of this wiring battery -> starter. The ground side will be a black wire of similar size most likely battery->engine. Give this a look see also. You may need to disconnect the wires to check them adequately. Please note if the wiring can not carry adequate electricity to the starter it will appear as if the batteries are discharged.
I guess you know to determine if a battery is fully charged you can take a specific reading?
The starter may be pulling so much current through marginal wiring there is not enough electricity left to correctly fire the spark plugs.

TRUE GRIT

You're getting closer to a running engine. Stay with it. Aren't boats fun?

[Quentin_D]

I didn't check the battery terminals. I will do it this weekend !

Yes boat are fun ! But it will be even better when the A4 will run and we'll be sailing

Hopefully it will run this weekend !

[Ken Rockwell]

First try hooking the battery to the coil, if it doesn't work try filing the points, also bring a spare coil. I think you have enough spark to make it fire. Try draining the float in the carb before you crank it. I think you may have a carb issue. The starting and running fast and dying might mean some kind of air leak. Maybe someone took it appart and ripped the gasket. Disconnect the fuel line going into the carb and make sure it's pumping fuel. Also see if the carb bolts are tight maybe it's something simple. Maybe someone put the float in upside down, I've done that more than once. Wet plugs could mean flooded. In fact make sure the needle valve is sealing. And make sure the floats aren't full of fuel, this is uncommon but it happens.

[Marty Levenson]

To recap: First we confirmed compression as the mechanic had found it very low a few months ago. Seems good now. Put some MMO in all cylinders to sit for a couple days.

Now we are working on getting a good spark. Initially there was none - so changed ugly rotor and got spark on some plugs. Changed cap and wires and have weak spark on all. Battey was too low to continue, so returning to the boat today with two charged batteries. Have a spare, good coil, so if no good spark at the coil primary wire today, we'll change the coil.

If no start will look at timing, though wire sequence is correct and no reason to distrust it yet.

Once spark and timing are good we'll work on the gas if no start. We smell gas on the plugs, so know gas is getting there. The carb was professionally rebuilt by the PO last year, but I have a good spare carb to swap out to help diagnose issue there simply. Also will test the quality of gas by taking a sample from the Racor. Will also put a new filter on the Racor. If still no start will try new gas using an external tank.

That's the plan! Am I missing anything?

[JOHN COOKSON]

Don't forget to confirm the choke is closing all the way.

TRUE GRIT

[Marty Levenson]

Wired up the recharged batteries, checked one plug for spark, saw it was yellow. Tried the primary coil wire, saw it too was weak. Changed the coil and she fired right up. Ahhhhh.

Had an issue with stalling below 1500 RPM, so reset the carb mixture control. Perfect!

Next question is trusting the temp gauge, as it didn't seem to move after ten minutes running, five in gear. Next weekend they have to move the boat about two hours away, where she will be on a mooring, so a bit of a rush now. I have a cheapo infrared temp gun to loan them - would that be good enough for the journey? Can't see why not.

Thanks for all the support - writing and feedback help me clarify how to proceed. For the new boat owners it has been a quick, effective learning curve.

[JOHN COOKSON]

Marty
You handled this situation like a true Afourian.
It is good to have high caliber people like you on board.
You can work on my engine any time.

TRUE GRIT

[Marty Levenson]

Thanks, John. It really is fun, and they are nice people, but really the hook is solving the puzzle! (plus I brush up on my troubleshooting skills).

[CalebD]

Good job Marty. You get good karma points while brushing up your troubleshooting skills. Win-win.

[Marian Claire]

Good karma is right. Well done.
I have an inexpensive oven thermometer as a back up, the flat base is wedged in between the head and manifold. It reads about 15 to 20 degrees above my gauge. The temp sensor for the gauge is mounted at the exit of the manifold.
http://www.moyermarine.com/forums/pi...&pictureid=611

Dan S/V Marian Claire

[sastanley]

Marty, I do not see any reason why a handheld temp gun would not be sufficient. I recommend getting some readings before the journey (tied to the dock), so they know what to expect, or to see anypotential issues before departing.

[Marty Levenson]

To get a good idle we had to adjust the carb's rich/lean screw all the way in (rich). I was wondering if that would indicate that the distributor needs to be turned clockwise slightly?

If so, would the procedure be to turn the rich/lean screw out a full turn, start the engine, and then rotate the dist until able to find a good idle?

Never understood why retard/advance od the dist affects richness...?

Thanks!

[JOHN COOKSON]

Originally Posted by Marty Levenson

To get a good idle we had to adjust the carb's rich/lean screw all the way in (rich). I was wondering if that would indicate that the distributor needs to be turned clockwise slightly?
If so, would the procedure be to turn the rich/lean screw out a full turn, start the engine, and then rotate the dist until able to find a good idle?
Never understood why retard/advance od the dist affects richness...?
Thanks!

Retard/advance does not affect the rich/lean/speed idle setting on the carb.
The best way to summarize is to say is carburetor rich/lean/speed setting will compensate for problems or settings in the ignition system. Said another way sometimes it is necessary to increase to increase idle speed/richness to get the engine to idle when there are problems in the ignition side.
The first step is to get the ignition side correct or as correct as possible. Then play idle speed against idle richness until you have a satisfactory idle. If you can't get a decent idle this way you need to look a bit deeper. Maybe there is crud in the carb idle circuit or something not right with the distributor. Be sure the advance is working correctly. Often over looked.
I was able to get my idle down to ~ 600 RPM this way. I can shift on to and out of gear at idle and the engine does not die. I'm so close to the edge if I don't get the dwell setting absolutely correct the engine will not idle at all. It dies when I try to idle it.

TRUE GRIT