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-   -   If sparkplugs could talk (https://www.moyermarineforum.com/forums/showthread.php?t=11075)

tmcdonagh 05-04-2019 08:20 PM

If sparkplugs could talk
 
3 Attachment(s)
Now that I am close to retirement, I have decided to take on tasks I thought I did not have the time for as a busy working slob. I tacked the gas filter and oil change. I barely avoided creating a superfund site with both operations. I then took on the spark plug change out. It was a crusty nasty mess but I did not break any on the way out. Please see the pictures of the business end of the plugs. They are arranged from 1 through 4. The last two picks are of 1 then 4. What are your thought?
A little history, she has been inning a bit rough this last year with the engine cutting out unexpectany and has been a rough starter.

Thoughts?

Tom

tenders 05-04-2019 09:21 PM

I'm not an expert on spark plugs but what those tell me is that (1) you have had water in your engine room that has rusted the outside of the plugs (ie, that rust could be an engine problem if it is the head that has leaked that water), (2) the first two plug tips look just about a perfect "toasty" brown, and (3) it is not unusual for the last two plugs to show signs of a richer mix.

So my read would be that you need new plugs, make sure the plug wells are free from water, and probably look to the carb, fuel, or ignition for causes of ill-running.

Dave Neptune 05-07-2019 11:10 AM

Talking plugs
 
Tom, the plugs don't actually talk but they do leave clues to be read.

First, the lack of color on the electrode porcelain indicates a plug whose "heat range" is to hot as there is very little deposited, dark or light. A cooler plug will make more power, run smoother and allow deposits to coat the ceramic which is nothing more than a heat sink.

The darker color on the ground indicates a pour burn inside the cylinder. This poor burn most likely is the timing is to far advanced.

The color that shows is OK for "economy" however more power and cooler running engine needs a bit more color like Jerry mentioned.

Try a set of stock range plugs for a couple of hours and take another "read" of the color. You want to see the beige~tan on the porcelain and about the same on the ground albeit a bit darker. Set the gap to .030 with points and if you run an EI go to at least .035/. The additional gap will idle smoother and start faster too, a big advantage of the EI systems.

Do you know if the plugs shown are in the same heat range or did you go hotter for some "fix-it" reason?

When installing the plugs give the entire outside of the plug a thin coat of dielectric silicone. This aids in both rust prevention and heat transfer through the boots by maintaining "contact' for good heat transfer and the boots won't tear when removing:rolleyes:.

NOTE the boots are a big part of the "heat sink" equation related to plug running temps.

Dave Neptune :cool:

RobH2 05-07-2019 04:49 PM

Awesome info Dave...!

tmcdonagh 05-07-2019 05:40 PM

Quote:

Originally Posted by Dave Neptune (Post 116658)
Tom, the plugs don't actually talk but they do leave clues to be read.

First, the lack of color on the electrode porcelain indicates a plug whose "heat range" is to hot as there is very little deposited, dark or light. A cooler plug will make more power, run smoother and allow deposits to coat the ceramic which is nothing more than a heat sink.

The darker color on the ground indicates a pour burn inside the cylinder. This poor burn most likely is the timing is to far advanced.

The color that shows is OK for "economy" however more power and cooler running engine needs a bit more color like Jerry mentioned.

Try a set of stock range plugs for a couple of hours and take another "read" of the color. You want to see the beige~tan on the porcelain and about the same on the ground albeit a bit darker. Set the gap to .030 with points and if you run an EI go to at least .035/. The additional gap will idle smoother and start faster too, a big advantage of the EI systems.

Do you know if the plugs shown are in the same heat range or did you go hotter for some "fix-it" reason?

When installing the plugs give the entire outside of the plug a thin coat of dielectric silicone. This aids in both rust prevention and heat transfer through the boots by maintaining "contact' for good heat transfer and the boots won't tear when removing:rolleyes:.

NOTE the boots are a big part of the "heat sink" equation related to plug running temps.

Dave Neptune :cool:

Thanks Dave!. Oh, plugs don't talk! I thought they were not listening.:cool:

I replaced the plugs with Champion RJ12C's and gapped that @ 0.04 as suggested on the forum. I will go back and remove, regap at 0.03 as I don't have the electronic ignition yet and spray with the dielectric silicone. Are there better spark plug wires for heat dissipation?
The plugs were leftover by the previous owner and I have no knowledge of why they were installed.

After installing a new gas filter and plugs she still runs rough for 1-2 minutes, coughing, stumbling and backfiring. She settles down nicely after that time. If I restart her right away, it runs normally. If she sits for 4-6 hours or overnight, the histrionics return. I have not been able to pressure test her on the water as of yet.

Thanks again!

Boat 05-11-2019 12:00 AM

your timing looks off to me.

tmcdonagh 05-13-2019 11:12 AM

The Saga continues..
 
Returned to the boat this weekend armed with all the suggestions and best wishes.
Here's what I did.

Tested compression on all cylinders and they all checked out at ~90 PSI.
Re-gapped spark plugs from 0.04 to 0.03 as suggested.
Injected an ounce or two of MMO into each cylinder and allowed to sit for 30 minutes after a few engine cycles.

Engine stated very rough after 10-15 attempts. Coughed, backfired and sputtered for 2 minutes and would not tolerate choke without stalling. After the 2 minutes or so she settled in and I could run the throttle up to max with no problem. Exhaust smoke was minimal but there seemed to be a bit more oil in the water than I generally notice. Applying a load to the engine by putting it into forward gear caused the engine to cough, backfire, sputter and stall.

I pulled the spark plugs and found plugs 1 and 3 carbonized and sooted while 2 & 4 were clean.

No Joy.

Any suggestions?

Thanks, Tom

JOHN COOKSON 05-13-2019 06:32 PM

Is the prop clean and free of fouling?

TRUE GRIT

tenders 05-13-2019 09:51 PM

Are you certain the plug wires are run to the correct plugs in 1-2-4-3 order coming off the distributor? If you can get it running and idling again, pull off one plug wire at a time and confirm that each one is firing. She may not be "firing on all cylinders," so to speak.

Is the exhaust free and clear, ie, not blocked with failing hose internals or a kink? The engine could be choking on its exhaust, which can get worse on loading (ie putting it into gear).

Are the advance weights and springs free to move smoothly underneath the distributor?

tmcdonagh 05-14-2019 07:49 AM

Prop free?
 
Quote:

Originally Posted by JOHN COOKSON (Post 116760)
Is the prop clean and free of fouling?

TRUE GRIT

Pretty sure John. Prop is clean as she was just splashed and nothing is evidently wrapped around the prop.

Thanks,

Tom

tmcdonagh 05-14-2019 07:54 AM

Quote:

Originally Posted by JOHN COOKSON (Post 116760)
Is the prop clean and free of fouling?

TRUE GRIT

Quote:

Originally Posted by tenders (Post 116762)
Are you certain the plug wires are run to the correct plugs in 1-2-4-3 order coming off the distributor? If you can get it running and idling again, pull off one plug wire at a time and confirm that each one is firing. She may not be "firing on all cylinders," so to speak.

Is the exhaust free and clear, ie, not blocked with failing hose internals or a kink? The engine could be choking on its exhaust, which can get worse on loading (ie putting it into gear).

Are the advance weights and springs free to move smoothly underneath the distributor?

Hi Tenders,

Those are all great questions.

WRT The exhaust, I am not sure and will have to check.
The wiring appears correct. I will check spark on all cylinders too.
Digging into the innards below the distributer scares me but it sounds like a dark place I may have to go.
Are the symptoms and remedies you suggest consistent with the motor not liking any choke?

Thanks,

Tom

JOHN COOKSON 05-15-2019 12:03 AM

Quote:

Originally Posted by tmcdonagh (Post 116671)
After installing a new gas filter and plugs she still runs rough for 1-2 minutes, coughing, stumbling and backfiring. She settles down nicely after that time. If I restart her right away, it runs normally. If she sits for 4-6 hours or overnight, the histrionics return. I have not been able to pressure test her on the water as of yet.
Thanks again!

This sure sounds like a sticky valve(s) to me. If you were able to run the engine at cruise RPM for an hour it might unstick it. Do you use MMO in your gas? Some* recommend outboard motor oil in the gas to unstick valves. I don't know the exact recipe.
*I think it was Dave N.

TRUE GRIT

tmcdonagh 05-15-2019 06:25 AM

Quote:

Originally Posted by JOHN COOKSON (Post 116774)
This sure sounds like a sticky valve(s) to me. If you were able to run the engine at cruise RPM for an hour it might unstick it. Do you use MMO in your gas? Some* recommend outboard motor oil in the gas to unstick valves. I don't know the exact recipe.
*I think it was Dave N.

TRUE GRIT

Hi John,

I treated the cylinders for about 1/2 hour with MMO and noted no improvement. I did not try it as a gas treatment as of yet. Thanks, it is now on my list.

Tom

JOHN COOKSON 05-15-2019 10:07 AM

Quote:

Originally Posted by tmcdonagh (Post 116777)
Hi John,

I treated the cylinders for about 1/2 hour with MMO and noted no improvement. I did not try it as a gas treatment as of yet. Thanks, it is now on my list.

Tom

MMO into the cylinders probably did not get the MMO to the valve area.
A compression test on a cold engine would probably give you the most information.

TRUE GRIT

tmcdonagh 05-15-2019 10:22 AM

Quote:

Originally Posted by JOHN COOKSON (Post 116781)
MMO into the cylinders probably did not get the MMO to the valve area.
A compression test on a cold engine would probably give you the most information.

TRUE GRIT

Thanks John, I will try adding it to the fuel. Compression was tested on the cold engine and found to be around 90 psi for all cylinders.

Tom

tenders 05-18-2019 09:42 AM

There are two scenarios that bear mention for sticking valves.

The first is a stuck valve that will not move and that shows diminished or zero compression during a test - your reading shows your engine doesn't have this.

The second might be better termed a "sluggish' valve in that SOME of the time in operation it doesn't move to the fully closed position for each cycle, making the engine run rough. My engine has no thermostat and a completely closed bypass, so it runs relatively cold, and exhibits this symptom very slightly sometimes. I run the bottle-recommended dose of Marvel Mystery Oil in the fuel 100% of the time and it solves the sluggish valve situation 100% of the time. Don Moyer has suggested you can run double the recommended dose without concern. (I think two-stroke outboard oil accomplishes the same thing, with perhaps a little more smoke.)

Maybe this will clear up your situation, and once the valve cycles a few hundred thousand times you won't need the additive any more.

tmcdonagh 05-20-2019 10:46 AM

Progress?
 
Quote:

Originally Posted by tenders (Post 116849)
There are two scenarios that bear mention for sticking valves.

The first is a stuck valve that will not move and that shows diminished or zero compression during a test - your reading shows your engine doesn't have this.

The second might be better termed a "sluggish' valve in that SOME of the time in operation it doesn't move to the fully closed position for each cycle, making the engine run rough. My engine has no thermostat and a completely closed bypass, so it runs relatively cold, and exhibits this symptom very slightly sometimes. I run the bottle-recommended dose of Marvel Mystery Oil in the fuel 100% of the time and it solves the sluggish valve situation 100% of the time. Don Moyer has suggested you can run double the recommended dose without concern. (I think two-stroke outboard oil accomplishes the same thing, with perhaps a little more smoke.)

Maybe this will clear up your situation, and once the valve cycles a few hundred thousand times you won't need the additive any more.

Thanks Tenders for comments and ideas. Here is a summary of what I have done.

1. Checked compression and all cylinders are at about 90 psi cold.
2. Changed oil and found it to be dirty but not water contaminated.
3. Changed out spark plugs gapped @ 0.03.
4. Replaced spark plug wires, distributer cap and rotor. I have electronic ignition.
5. Treated cylinders with MMO for 30 minutes.
6. Checked spark and found to be good on all cylinders.
7. Checked gas for particulates and water from hose going to electric fuel pump. I have no filter/water separator before the pump. I am working on installing a Racor unit. Fuel seemed clean and waterfree

After all this, the motor starts right up without any complaints. I can run the throttle up to max rpm with no load. When loaded she can handle up to 1/4 throttle or so but maxes out at the midrange rpm. If I push the throttle higher I see no increase in rpm and if I push to 3/4 and beyond, the motor sputters, backfires and quits.
I am now investigating fuel quality, blocked fuel tank vent pipe, weak fuel pump and carburetor issues.

Thoughts?

Thanks,

Tom

JOHN COOKSON 05-20-2019 05:54 PM

Quote:

Originally Posted by tmcdonagh (Post 116883)
Thanks Tenders for comments and ideas. Here is a summary of what I have done.

1. Checked compression and all cylinders are at about 90 psi cold.
2. Changed oil and found it to be dirty but not water contaminated.
3. Changed out spark plugs gapped @ 0.03.
4. Replaced spark plug wires, distributer cap and rotor. I have electronic ignition.
5. Treated cylinders with MMO for 30 minutes.
6. Checked spark and found to be good on all cylinders.
7. Checked gas for particulates and water from hose going to electric fuel pump. I have no filter/water separator before the pump. I am working on installing a Racor unit. Fuel seemed clean and waterfree

After all this, the motor starts right up without any complaints. I can run the throttle up to max rpm with no load. When loaded she can handle up to 1/4 throttle or so but maxes out at the midrange rpm. If I push the throttle higher I see no increase in rpm and if I push to 3/4 and beyond, the motor sputters, backfires and quits.
I am now investigating fuel quality, blocked fuel tank vent pipe, weak fuel pump and carburetor issues.

Thoughts?

Thanks,

Tom

Have you checked the advance yet?
Why are you posting the same information in two different threads?

TRUE GRIT

tmcdonagh 05-20-2019 10:31 PM

Advance issues?
 
Quote:

Originally Posted by JOHN COOKSON (Post 116895)
Have you checked the advance yet?
Why are you posting the same information in two different threads?

TRUE GRIT

Hi John,

I will have to research the advance. I posted to the other thread as I think this thread moved away from electrical and was more fuel oriented.

Sorry for the cross post.

Tom

JOHN COOKSON 05-20-2019 11:57 PM

The forum would be able to help you better and more efficiently if you started a new thread detailing the current problem(s).

TRUE GRIT

tmcdonagh 06-10-2019 09:51 AM

An update
 
With suggestions from the forum members and Don, I disassembled the distributor, exercised the advance weights and springs and treated with light machine oil. Before this, I could not hand turn the rotor shaft. The motor runs well not with no issues. Thanks to all that have made suggestions and have encouraged me to keep moving forward on this project.

Tom

Boat 06-14-2019 12:29 AM

have you timed the motor? i havent seen in here where you have. the tan color on the plug should be at the bend in the tip.

tmcdonagh 06-14-2019 05:38 AM

Have I timed the engine?
 
Hi Boat,

Thanks for the suggestion. I have not done this as of yet. I am reading up on the topic and trying to find any marks on the engine to facilitate the process. If I can’t find marks, I am guessing I need to determine TDC for cylinder 1 then go from there. I am new to all this mechanical stuff and the learning is like drinking from a fire hose. I’ll keep you updated! Thanks.

roadnsky 06-14-2019 10:31 AM

2 Attachment(s)
Quote:

Originally Posted by tmcdonagh (Post 117238)
...I am reading up on the topic and trying to find any marks on the engine to facilitate the process. If I can’t find marks, I am guessing I need to determine TDC for cylinder 1 then go from there.

Here are a couple of instructions for finding TDC and Timing
(The 2nd page of the Troubleshooting doc has a simple timing procedure)

Also a couple of good threads here and here for you.


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