Valve Tap and No Spark Sparkplugs

[chrisoelder]

Hi All!

I have an interesting one here. On 10/14 I decided to go out for a sail. It had been a month since I had been down to the boat so when I started up the engine she needed a little extra TLC to get her going but once she was warm she ran well. I started hearing a clinking sound out from the back of the engine, I knew it right away. My valve tap issue in the 4th compartment has returned. I let the engine run for another 25-30 minutes hoping that the movement of the engine would shake the valve free. When I ran her a month ago she was in good shape. At the 30-minute mark, the engine cut off, like someone turned the ignition switch. I took a look at my Moyer handbook (aka A4 Bible) and my suspicion was confirmed - sparkplugs. Got my extra set of sparkplugs out and swapped them. To my surprise, she wouldn't start up. I got on my rubber gloves and tested the spark plugs with my remote starter switch - no spark. I'm assuming this issue now deals with the coil or distributor but I'm no expert or electrician. I have broken down each issue below.

Sparkless Sparkplugs:
When performing the sparkplug test, I placed the sparkplug on the engine (away from the plug hole) to ground the connection and used rubber gloves to hold the cable that goes from the distributor to the plug. Made sure it was dark so I could see the spark but no luck. I did refer back to the A4 Bible and started to take a look at the distributor. I have images linked below for reference to each section:

Distributor Cap >
Level One of the Distributor >
Level Two of the Distributor >

The second level is pretty dirty and rusted. Not as bad as the example in the A4 Bible but do you think that could be the issue?
Does anyone know an easy way for me to test my coil and distributor to see where the issue is?

Valve Tap:
I've fixed a couple of valve taps over the past 5 years but this one looks and acts differently than I remember the others. Currently, I have the same compression in 1 and 2, 3 is about 3-5 PSI less, and 4 has zero compression (which makes sense). On the 14th I was hand-cranking the engine and sprayed a bit of WD-40 in the plug hole, while hand-cranking you can see the valve popping up and down sporadically, and doesn't seem to close. I have included a video below for reference:

Last valve movement while hand cranking (liquid bubbling is the WD-40) >

When I went down today (15th), the valve now doesn't move while hand-cranking but does move when I use my remote starter switch. Is that normal or concerning?
Does this issue look like a normal valve tap or is it a broken spring?
Could this be a part of the reason the engine won't start? I've been told the A4 can run on as little as 2 chambers but not 100% sure.

Oil Change Question: After this is all said and done, I'm planning on performing an oil change. I read in another thread that some of you add MMO with the oil change. Do you pour it into the Oil Filler?

Thank you for the help and advice! Apologies for the lack of proper terminology.

- Chris

[joe_db]

You need to start at the start.
Pull the wire from the center of the distributor that runs to the coil. See if that sparks. If so, the problem is downstream of the coil. If not, it could be the coil itself or upstream from it.
FYI - I can't imagine all 4 spark plugs going bad at the exact same time. That is a gradual process, not sudden.

[Dave Neptune]

First thing to check as the shut down was all of a sudden is for voltage at the positive side of the coil with the key on.

The distributor looks terrible. I would suggest since you should be replacing the cap, rotor, points and condenser that you opt for an EI. The biggest reason for the EI suggestion is all of the rust under the cap. This causes excessive wear on the distributor cam that operates the points and setting the points properly can no longer be done correctly with a feeler gage so a dwell meter should be used. And for the same money as the above parts and a dwell meter you can upgrade the whole system.
The (2nd) underside of the distributor looks even worse. The entire centrifugal advance assembly should be cleaned of all the rust and the slides of the advance assembly should be buffed and lubed so they move freely and I would replace the springs if you go to the EI again I strongly suggest that.
It looks as though the "felt" (under the rotor) is still in place for lubricating the counter shaft which is what the centrifugal advance moves as RPM's increase. It can be cleaned and should be oiled periodically so the shaft rotates freely. When converting to an EI a coil should come with the kit. Once you confirm power at the coil then check for spark as per Joe's post.

As far as the valve is concerned allow it to sit with the WD-40 or better yet some MMO. Once you get the engine running use some "top oil", I suggest a 2 stroke synthetic WC-3 rated added to the fuel at 100:1 or you can use MMO. After running for a while the valve will probably shake loose and work properly.

Dave Neptune

[Sam]

You have good advice from Dave and I am going to make a few specific suggestions that you may find helpful.
The condition of the distributor and components indicates to me that you may not be comfortable with periodic maintenance in the ignition circuit. My guess is that you would not get a good spark from the distributor to the block which is why you are not getting a spark from the plugs. {Watch Don's video on "flicking the points, discharging the coil and checking for spark]. I am comfortable with points [I 'm pretty old and grew up with them], but I do some maintenance/check twice a season here in Chicago. Recommend you might want to consider going to EI. Specifically:
- order new advance weight springs, cap, rotor... points/condenser or an EI conversion Kit.
- disassemble & thoroughly clean and lubricate the distributor components below the points plate. Again, for less maintenace requirements I would go to EI.
- recheck the timing and adjust points if used.
- Based on distributor condition I am going to guess new plug wires and new/spare coil may be a prudent purchase.

You may find that a plug[s] without/week spark leads to fouling leads to carbon buildup leqds to valve sticking. Personally I have hesitated with the EI conversion because I like to tinker but may do it next season. Last dozen years have converted 2 friends' boats in the harbor to EI because they don't. * Hope this helps.

[chrisoelder]

This is all great information! Thank you! I am somewhat new to owning a boat and A4s and made the mistake of not checking up on the distributor and keeping it clean/ lubed - Now I know . I'm leaning towards the switch to EI. I'm going to clean the distributor and test the coil today.

I appreciate all the help and advice! Will report with the status and next steps shortly.

Thanks!
Chris

[chrisoelder]

Dumb Question Alert

Hi All!

Thanks again for the advice. Went down last night and got good volt meter readings from the Coil and a nice spark. I started working on cleaning the distributor. I did some research but could not find a clear answer. What kind of oil/grease do you use on the cam felt under the rotor and the weights/springs (the centrifugal advance assembly I believe it's called)?

1. For the cam felt under the rotor: Would Liquid Wrench Machine Oil work for this?
2. For the weights/springs: I saw online that using stp moly ep grease would work but I'm not sure if that is current or correct.

Any advice or tips as to what is best from your experience? Even if I go with EI, it is great information to have in the old noggin. Using this as a learning experience

Thanks for everything and your patience with my ignorance!
Chris

[Sam]

Without over thinking the issue both recommendations are fine. Years ago I would lubricate distributor componets with spray lithium grease - got a little messy over time. My go to is regular use of PB Blaster Multi -Lube. For the felt I have a little can of standard "3 & 1 oil" in the engine compartment, the small tip makes it easy to administer.

[chrisoelder]

Success but wait...

I was able to get the distributor all cleaned and put back together and now I have a great spark from the sparkplugs, The engine still won't start up though.

That will have to wait for a moment because I believe there is a bigger issue. I added some MMO into the chamber with my valve tap and let it sit while I worked on the distributor. When I checked the spark plug hole after fixing the distributor last night, the top of the valve was sitting right where the spark plug would be - that can not be good. Seems more than a valve tap now and Im not sure what the next steps are. I think I will need to either take off the cylinder head and/or the valve panel so I can replace the valve. I have a video linked below of the valve after it fell back into place but it is moving a lot. Thank god it didn't fall into the piston!

Video of Valve going crazy >

What are your thoughts?
Thanks!
Chris

[Dave Neptune]

Hard to tell for sure but the valve looks bent or possibly broken. Time to pull the head and valve galley cover to see what is going on.

Dave Neptune

[chrisoelder]

Used Valve Compressor for sale?

Hi all!

Alright, I got to the valves and I have a broken and bent valve. Now, I am at the point of replacing them but I need a valve compressor. Before I buy a new one from Moyer I wanted to quickly see if anyone has a used one they are looking to get rid of or a third-party one they prefer.

Thanks!

https://moyermarine.com/product/valve-spring-compressing-tool-tool_02_165/

[Dave Neptune]

FWIW, I ground a notch into the base of a large "C-clamp" and it worked just fine. I did grind a bit of the underside of the base away too to make easier access for my fingers.

Dave Neptune

[hanleyclifford]

You have good advice from Dave and I am going to make a few specific suggestions that you may find helpful.
The condition of the distributor and components indicates to me that you may not be comfortable with periodic maintenance in the ignition circuit. My guess is that you would not get a good spark from the distributor to the block which is why you are not getting a spark from the plugs. {Watch Don's video on "flicking the points, discharging the coil and checking for spark]. I am comfortable with points [I 'm pretty old and grew up with them], but I do some maintenance/check twice a season here in Chicago. Recommend you might want to consider going to EI. Specifically:
- order new advance weight springs, cap, rotor... points/condenser or an EI conversion Kit.
- disassemble & thoroughly clean and lubricate the distributor components below the points plate. Again, for less maintenace requirements I would go to EI.
- recheck the timing and adjust points if used.
- Based on distributor condition I am going to guess new plug wires and new/spare coil may be a prudent purchase.

You may find that a plug[s] without/week spark leads to fouling leads to carbon buildup leqds to valve sticking. Personally I have hesitated with the EI conversion because I like to tinker but may do it next season. Last dozen years have converted 2 friends' boats in the harbor to EI because they don't. * Hope this helps.

Like you I was one of the last holdouts before going to EI. The inescapable fact is that lobes on our distributors have been worn down to the point that we have to get into single number point gaps to get the dwell we need. The result is burned points and lots of tinkering. I went to EI and am living happily ever after.

[Dave Neptune]

While you have been troubleshooting have you perhaps left the key on? Leaving the key on can absolutely fry any coil. I post this as advise since it so often happens when troubleshooting. It often happens when an engine shuts down and the engine is not turned off too. Perhaps this happened in your case.

Converting to an EI or FWC are the best things you can do with these old A=4s.

Dave Neptune