Engine won't start

[MightyMike]

Hello,
I have not been able to start my motor this season. First I thought it was a fuel issue, because I left fuel in the carburetor over the winter. I was able to start the engine, but it would only run with the choke out and at idle. It would die as soon as throttle was increased.

Based on what I’ve read here, I removed and cleaned the carb and reinstalled. It’s the first time I’ve done that but it seemed to go back together well. I also changed the Racor filter and installed new plugs

It seems to me the cylinders are getting gas. When removing the plugs after trying to start they are wet and smell of gasoline.

I’ve moved on to the spark. I did the static coil check as shown in Don’s video. The primary coil is showing 3.8 ohms and the secondary coil 10.71. I am assuming that is 1071 but at the wrong scale. There is a spare coil left by the previous owner and the results are similar on that one.
I have been unable to do a live spark test.

When I removed the distributor, which is quite a trick on this boat, I found the rotor contact dirty with carbon and what appears to be burns on each side of the contact in the plastic. The contact slides around a bit from side to side,

I am thinking I have found the problem, but don’t want to order parts until I am sure. Should I replace just the rotor or also the electronic ignitor as well. The distributor cap seems fine except for the dinged up screws.

Thanks for your help.

[Dave Neptune]

Replace the cap & rotor as a set always. You will need to check for spark. Then look for why there is no spark in the wiring, voltages and such. Only after confirming the spark from the coil and still no spark to the plugs would it be time to look at the igniter itself. The trigger in the EI is what energizes the coil to send a spark through the distributor. The EI is the last check.

Dave Neptune

[JOHN COOKSON]

Take voltage reading at coil + with the key on. Let's be sure there is power to the coil.

For sure replace any parts that don't look serviceable.

If you have questions about the parts send picture.

ex TRUE GRIT

[Peter]

Mike - the 10.71 in the secondary is 10.71 kOhms which is in the normal range.

I am a little confused by Dave’s suggestion that “ Only after confirming the spark from the coil and still no spark to the plugs would it be time to look at the igniter itself. The trigger in the EI is what energizes the coil to send a spark through the distributor. The EI is the last check.”

I think if you get a nice spark from the coil the igniter is fine. Am I wrong?

And finally, to be perfectly clear, you were able to start the engine (although it would not run well) before the carb rebuild but not afterwards? If that is the case, why are you thinking that you now have an ignition problem? If the engine ran before the carb rebuild, does that not suggest that the ignition is ok? Definitely check for spark before ordering any parts.

Peter

[ndutton]

When I removed the distributor . . . . .

Possible red flag here. Did you carefully mark the rotor position prior to removal? No movement of the crankshaft while the distributor was removed? Distributor reinstalled with the rotor and distributor housing positioned precisely as before? Unless all three of these protocols were carried out you are in for a start from scratch timing exercise.

[Dave Neptune]

The coil can be fine and throw a good spark when doing a coil check. If there is a good spark from the coil it does not mean that the igniter will trigger for a spark to be sent through the distributor to the proper plug.
Coil good and a bad igniter no spark to the plugs.
Igniter good and a bad coil also equals no spark to the plugs.

The igniter tells the coil to throw a spark when the rotor is pointing at the plug at the top of the compression stroke. Either one can be bad or very rarely both. these are separate parts in the same system.

Dave Neptune

[MightyMike]

Take voltage reading at coil + with the key on. Let's be sure there is power to the coil.

For sure replace any parts that don't look serviceable.

If you have questions about the parts send picture.

ex TRUE GRIT

Here is a picture of the rotor.

I will test for power at the coil + when I go out to the boat later.

Thanks.

[MightyMike]

Mike - the 10.71 in the secondary is 10.71 kOhms which is in the normal range.

And finally, to be perfectly clear, you were able to start the engine (although it would not run well) before the carb rebuild but not afterwards? If that is the case, why are you thinking that you now have an ignition problem? If the engine ran before the carb rebuild, does that not suggest that the ignition is ok? Definitely check for spark before ordering any parts.

Peter

Thanks for confirmation on the secondary coil values.

My troubleshooting methodology does seem suspect.
I left out some intermediate steps after cleaning of the carb. I also changed plugs and filtersbefore cleaning the carb. After reinstalling the carb I had to solve leaking at the sediment bowl and scavange tube. Once I solved for those I was clearly getting fuel in the cylinders and the moved onto the spark. Perhaps too soon.

I think it makes sense now to focus on the spark with all the good suggestions here before working back to the carb.

Thanks

[MightyMike]

Possible red flag here. Did you carefully mark the rotor position prior to removal? No movement of the crankshaft while the distributor was removed? Distributor reinstalled with the rotor and distributor housing positioned precisely as before? Unless all three of these protocols were carried out you are in for a start from scratch timing exercise.

I did not turn over the engine with the distributor cap off. The rotor appeared to drop back in the very same position. Something new to worry about, I guess.

[roadnsky]

I did not turn over the engine with the distributor cap off. The rotor appeared to drop back in the very same position. Something new to worry about, I guess.

Hi Mike-
I think to be clear, Neil is concerned that you removed the ENTIRE distributor as opposed to JUST the cover and rotor.
Can you clarify?

[MightyMike]

Hi Mike-
I think to be clear, Neil is concerned that you removed the ENTIRE distributor as opposed to JUST the cover and rotor.
Can you clarify?

yes, to confirm, I just removed the distributor cap, not the entire distributor.

Thanks.

[JOHN COOKSON]

The rotor is scrap.
Quick question: Did you reconnect the spark plug wires in the correct firing order 1, 2, 4, 3?

ex TRUE GRIT

[capnward]

If you have to choke it to run, it is running too lean. Sounds like your distributor is ok, once you replace cap and rotor. EI is likely ok, if your spark is ok. Carb is probably ok as long as you reamed out the idle jet and other spots with a thin wire. If the idle jet was clogged, it wouldn't idle, but your problem is it won't accelerate. A clogged main jet would restrict fuel. Clogged ports in the side of the throttle throat will restrict acceleration.
Timing may be an issue. Sometimes turning the distributor a bit will enable it to start. Turning it clockwise retards the timing, and richens the mixture, from what I understand.
Did you reinstall the carb with new gaskets? If there is an air leak at the manifold gasket, the engine will run too lean, which could explain why it only runs with the choke closed. Also, make sure that your idle adjustment screw is one turn out from its seat, to begin with. Turning it out makes it run leaner. Always be sure of your firing order.
This forum never ceases to impress me, you are at the right place. Happy sailing!

[MightyMike]

We are back to the carb

I was able today to test out the coil.

With power on, I was reading 11.2 volts at coil +

With someone available to push the starter button we were
definitely getting a strong secondary pulse from the coil by holding the center coil wire near the block, as in Don's video. I only tested one plug, but we were getting a strong spark there as well.

We then tried to start the motor and we were able to start it after opening up the idle jet another full turn to 21/2 turns it ran for about 90 seconds with the choke open. The it just stopped. I then realized that I hadn't opened the fuel line.

We tried a few more times, but couldn't get it to kick over again.

I did not use a wire on either jet, but I did blast them both with carb cleaner when I had it apart.

I am going to play around with the idle settings tomorrow. Any other suggestions would be much appreciated.

By the way, I have a late model carb, but it does have an adjustable main jet.
I have experimented with different openings on that,from 2 to 4 turns out. I am not sure if that would impact starting, though.

Again,thanks for your continued support and advice.

[Dave Neptune]

The screw you are adjusting is for the "idle air" so open is lean and closed is rich.

Were you careful with the float setting?

Dave Neptune