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

[MightyMike]

Originally Posted by Peter

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]

Originally Posted by 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

Here is a picture of the rotor.

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

Thanks.

[ndutton]

Originally Posted by MightyMike

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]

Originally Posted by ndutton

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]

Originally Posted by MightyMike

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]

Originally Posted by roadnsky

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

[idreamOfSailing]

I noticed the cylinders have been wired in reverse from the distributor, meaning the 1-position on the distributor goes to number-4 cylinder, 2-position to number-3, 3-position to number-1 and finally 4-position to number-2 cylinder, so in terms of firing order, correctly I think. If however I were to rewire according to the book, would I simply find the top of true cylinder-1 (first from the flywheel) and connect to distributor position-1 and then follow the usual firing pattern for the other cylinders, or is there something else I should know? My thinking is, since the distributor is firing in correct order there's nothing that needs to change there. Thanks.

[ndutton]

Dream, I didn't see any mention of rotor position in your post. The distributor post that should be connected to cylinder #1 at TDC is the one the rotor is pointing to, then the remainder are connected following the firing order.

[idreamOfSailing]

Hi Dutton. Thanks for yuor response. I think I did mention it though. I said the position-1 on the distributor, which I take it you're calling position-1 on the rotor, currently goes to the number-4 cylinder. So, if I understand, all I need do is move that wire to the number-1 cylinder at TDC and then move all the other wires to their correct cylinder without changing any of the positions on the rotor. I'd have rotor-1 goes to cylinder-1, rotor-2 to cylinder-2, rotor-3 to cylinder-4 and rotor-4 to cylinder-3. Do I understand correctly?

[ndutton]

We may be talking about the same thing but maybe not. With the spark plug wires unchanged yet, when the #1 cylinder is at TDC (top of compression stroke, not top of exhaust stroke), lift the distributor cap and report which distributor post the rotor points to. That is, the post it points to has the spark plug wire going to which cylinder?

[idreamOfSailing]

I see what you mean now. Mine is electronic ignition and I have never opened it so would removing the distributor cap tell me the same story as for a non-electronic system?

[JOHN COOKSON]

Originally Posted by idreamOfSailing

Hi Dutton. Thanks for yuor response. to . Do I understand correctly?

I don't think you do.
You need to do what Neil said - verify the position of the rotor when #1 is at TDC compression.
If you change the position of the wires on the distributor cap, without rotating the distributor, and keep the same firing order, the spark will occur at the wrong time even though the firing order is correct.
Maybe I am not visualizing this correctly?

ex TRUE GRIT

[idreamOfSailing]

I get it. I need to see which post the rotor inside the distributor is pointing to when the true number-1 cylinder is at TDC. That post will be my new number 1 and the rest follow suite. Now, does the rotor spin clock-wise or anti like the flywheel?