A Bit of Bad Luck

[ElmaBay]

I'll endevour to keep the circumstances leading to my incident brief, however it may be of interest to some as to how it came about. Also it provides history to the event.
After a day of sailing with my family (crew) we were approaching the marina, which has a somewhat challenging entrance to say the least. The entrance is a channel of some 300 feet in length and 20 to 25 feet in width. We were entering the channel at high tide - giving me adequate depth mid channel for the 6.5 feet my boat draws. We were some 50 feet into the channel when a power boat approached from the opposite end and was hogging mid channel. I continued with my forward motion as I had the right of way, but the power boat was not giving me any width. Long and short of it is that I moved over to the port side slightly and hit bottom - not serious as it is gravel, but hard enough to get my crew excited. The power boat passed by with a smile on his face. In the process of trying to get the sail boat off the gravel it required more throttle than I would normally use. The boat did eventually come off the gravel with a little help from pushing with a pole, however in the process my throttle cable broke - resulting in the engine over speeding for what seemed to be forever, although I doubt if it was for any longer than a few seconds. It took that long for me to determine the cause of the over-speeding and to react by shutting the ignition off. We were able to get the boat out to deeper water, spent the night anchored out and got towed into the marina in the morning.

Current situation is that the engine will not start. This is where I need some assistance in figuring out what has gone wrong. So far this is what I have determined.

Good spark to the plug ends. The rotor spins. No water in the oil. Fuel to the intake side of the carb. I have not had time to check the outlet side. I believe fuel and spark to be alright.

Compression? This may be the problem. Compression test on a cold engine as per the following: 55 - 55 - 61 - 63. Up until this incident the engine has started first crack, usually without choke.

I've had a few guys look at the engine and all they can say is "Install a diesel." I don't believe this is the best answer. I think with assistance from you guys and some parts from Don, I can get this little engine up and running again for a whole lot less money and hazzle.

Looking for words of wisdom and suggestions.

[msauntry]

What do those guys say when they look at a diesel with problems? Install an Atomic 4?

You've got the right mind set. You can do this yourself with a little help from Don and the forum here.

Maybe give the distributor a careful look. Check the rotor and inside the cap for any damage. Put on a spare cap if one is handy. Are there points or electronic ignition? You've got spark it seems, so it can't be too bad. I'm thinking the high revs might have damaged or stuck the distributor flywheel springs. Check to see if the rotor springs back and forth a little bit as it should. Is it possible the timing has somehow been changed so that its just severely retarded or advanced? Mechanical fuel pump or electric? Perhaps the high revs damaged a mechanical pump's gasket and its not getting fuel. I'm guessing here...

The compression seems low. Maybe the valves have been thrown out of whack enough where they need to be reset. Best of luck!
Micah

[Marian Claire]

Check out the “non-starting check list” referred to by Roadnsky in the thread before this. Good info on the compression #s. Have you replaced the cable? I wonder if the connection to the throttle shaft could have slipped and changed the throttle valve position. Or is not opening the valve as it should. Good luck. Dan S/V Marian Claire

[Don Moyer]

ElmaBay,

While it's tempting to relate the incidence of over-speeding with the non-starting, the Atomic 4 is historically quite forgiving of these over-speeding episodes. I would also say that while your compression values are rather low, in our experience, the engine should still start. so I'm hoping that there is yet some other explanation for the non-starting we simply haven't thought of. Do you have recent (higher) compression values which support the assumption that the low compression is indeed resulting from the over-speeding?

One of the more relevant steps in the non-starting checklist (particularly since you have compression and ignition) is the check for raw fuel puddling in the bottom of the carburetor intake throat after trying to start. With the choke fully closed, in just 15 or 20 seconds of accumulated cranking there should be a puddle of fuel in the bottom of the intake throat. If the intake throat remains bone dry, the reason for the non-starting is almost surely a lack of fuel getting through the carburetor.

If we do end up looking for a connection between the over-speeding and the low compression, I'd start by removing the valve cover to check for broken valve springs.

Don

[roadnsky]

however in the process my throttle cable broke - resulting in the engine over speeding for what seemed to be forever, although I doubt if it was for any longer than a few seconds. It took that long for me to determine the cause of the over-speeding and to react by shutting the ignition off.

Hmmm, the line that jumped out at me was that the ignition was shut off while the engine was at high RPM.
Was that indeed the case or did you throttle back first?

Can you give a little more details as to the engine not starting?
Does it turn over strong or weak? Just not catching? Catches, sputters and dies? Any strange or unusual noises? Etc...

Follow Don's advice to see if you have fuel in the throat. That will answer the fuel delivery question. Part 3 of Spark, Fuel, Compression.
To save you time, I'll attach the NON STARTING CHECKLIST here. Read it through and see if something rings the bell...

[ElmaBay]

All good points. I have no previous histouy of the compression readings as I have only had the boat for a couple of months. The caus of the over speeding was the breakage of a cotter pin from the throttle linkage. I had no control of the throttle from the control panel, and so shut the engine down with the ignition switch from the control panel.

I have not been able to get to the carb to check for puddling of fuel, although I do realize this to be an important component of the search. The previous owner must have removed the screen (with difficulty) a few times as one of the screw heads is pretty much rounded right out. I will need to work on this before getting access to the carb throat.

I do believe that the problem could be fuel related. After cranking the engine for some time, and removing the spark plugs - expecting the top of the pistons to be soaked with fuel - they are all dry. I would have expected the engine to be flooded with much fuel in the cylinders. There are no strange or unusual noises - no loose parts rattling around within the block. All sounds normal.

The engine has two fuel pumps - one mechanical attached to the engine in the normal location as well as an electrical pump located on the engine side of the racor, perhaps five feet from the engine. The electrical pump works well as I am getting fuel to the carb - a good strong flow.

Too late to get to the boat today. Will check the carb throat tomorrow. Fuel - Air - Fire its got to be one of the three.

Thanx

Doug

[tenders]

> The previous owner must have removed the screen (with difficulty) a few
> times as one of the screw heads is pretty much rounded right out.

This isn't going to fix the immediate problem, but to address this particular issue you're going to need this handy bit of Moyerama:

http://www.moyermarine.com/images/fuel26.jpg

which is fifth from the bottom of this page:

http://www.moyermarine.com/cgi-bin/shopper.cgi?search=action&category=FCAR&keywords=all&template=Templates/B000_storebuilder.html

I am guessing you've boinked the diaphragm of the mechanical fuel pump by revving at high speeds. However, this is a wild guess; I don't even have a mechanical fuel pump.

[Don Moyer]

As coincidence has it, we are in receipt of yet another over-speeding report (that has not yet made it to the Forum) which suggests that over-speeding may lead to valve spring failure. In this other report, the electrodes of one of the spark plugs were smashed in the aftermath of the over-speeding event. As all of you know by now, the only moving parts directly under the plugs in each cylinder are the intake valves. As the saga unfolded, we also learned that spark plugs with exceptionally long threaded sections were being used which put the electrodes precariously close to the intake valves each time they opened.

During this other over-speeding event, we concluded that the valves "floated" upward a small amount (beyond the height that the springs would normally allow) until the one in the affected cylinder took out the electrodes on this one plug. Why was only this one plug affected; presumably because its spring was already slightly weaker than the others.

Prior to this individual contacting us, the damaged plug had already been replaced with one with an identical threaded length (too long) and the electrodes were taken out on that new plug as soon as the engine was started, indicating that this particular spring is now not only weak but probably broken as well. I'll try to report the conclusion of this other episode as soon as all the facts are in.

No matter how any of this turns out, we should all be careful when using any plugs that don't cross reference very close to the electrode depth of the O.E.M. plugs (Champion RJ8 or RJ12). From a photo we received of the damaged plugs in the above episode, the threaded sections of the plugs were glaringly too long.

Don

[ElmaBay]

Finally made it back to the boat tonight after work. Checked the carb throat for fuel after cranking for 15 to 20 seconds and there is in fact a small puddle of fuel in the throat. One thing I did notice, which I blieve to be a recent development since I've been tinkering around with the carb and manual fuel pump is that the sediment bowl appears to be leaking. The thumb screw at the bottom has been damaged by the previous owner and is somewhat difficult to loosen to examine the components. Will endevour to remove tomorow evening. Could be sucking air, but as mentioned, I believe this to be a more recent casualty of my exploration of the engine and not the root cause of the engine not starting.

As a side issue, I need to examine more fully the priming lever of the mechanical fuel pump as I suspect it is not working. I definately do not feel any resistance when activating it. Will remove outlet pipe ttomorrow and see if in fact it is pumping fuel.

Interesting story about the other chap with similar problems. Everybody else watch out, bad things happen in three's.

Doug

[knitchie]

A Bit of Bad Luck

Doug,
I don't want to be insulting, but it sounds like you may be new to the marine engine world. As you are turning over the engine repeatedly, keep your raw water thruhull closed so that you don't end up flooding you engine with water on top of whatever else is wrong.
Good luck,
Ken