A4 stalls in gear only

[Wavey]

Hello all. She runs fine in neutral. In forward it will bog down and die in about 5 seconds, and a bit longer in reverse.
Been a long week...prop is clean, same result when stuffing box is loosened. Carb is clean(fixed main jet). Points and rotor are clean and counter weights are clean and operating as they should.
I have loosened and tightened one notch until I am nearly out of my mind!
I have never adjusted reverse. It now runs but slips in forward with apparent decent reverse thrust. Then next notch in forward makes her stall.
Though we have a pedestal, I have checked the linkage and forward detent seems to be achieved each time.
What am I missing? Reverse adjustment? Trans or ring replacement?
Thanks in advance folks.

[thatch]

Your symptoms have all of the characteristics of prop-shaft bind. Since you have already loostened the stuffing box have you tried turning the output coupling by hand, while in neutral? If it does not turn easilly, I would suspect a strut bearing issue.
Tom

[tenders]

Possibly a blocked exhaust too. To troubleshoot: disconnect exhaust from engine flange, ignore exhaust pouring into cabin/engine compartment for a few seconds, avoid carbon monoxide poisoning, see if engine runs better.

[Wavey]

Thank you Thatch and Tenders. I will check shaft rotation and the exhaust. Pre-launch, the shaft did turn freely in the cutlass bearing though. She also seems to be pumping the usual amount of water.
Both worthwhile suggestions though.
Thanks

[Wavey]

Well, yesterday the prop shaft turned freely in neutral. Exhaust is clear. Pulled each plug while running and engine began to die when each plug wire was pulled so each one is good and coil appears alright. Wasn't ready for the shocks through insulated pliers and latex gloves though! Lots of spark jumping! Lol
So she still stalls in gear unless I have the forward adjustment ring sets where she slips which is no good.
Any other suggestions? Adjust reverse then forward? I'm lost.

[ndutton]

Your issue has to be in one of five areas:

1. Fuel - poor quality, poor supply, poor metering.
2. Air - too much or too little, inability to breathe (exhaust)
3. Compression
4. Spark - poor quality, poor delivery, wrong time
5. Load - excessive load on the engine in forward (where you believe the problem lies)

Give her fuel and air in the right proportions, light it with a good spark properly timed and don't bog her down and she'll run fine. The question is which one is out of whack?

Good troubleshooting tests these possibilities in a logical order, is not belief based and doesn't gloss over anything. I have a few questions about where your troubleshooting is at right now:

• You've been trying to adjust forward gear repeatedly with no improvement. Have you been following Moyer's adjustment procedure to the letter? If you have, the trans should be off the table by now. If you haven't followed Moyer's instructions, you should.
• You've declared the exhaust clear. How was this determined? Did you run the engine in gear with the exhaust removed as suggested by Tenders?
• You said the coil appears alright. What about its appearance suggests it's alright?
• Lots of sparks jumping? Jumping where? Have you tried observing the engine running at night in the dark? Maybe mist it with water from a sprayer? My thought went immediately to plug wires.
• No mention the firing order was double checked.
• Have you tried advancing/retarding the timing?

[Dave Neptune]

Wavey, I to suspect wires to be part of the problem~try what Neil said.

It is common to have an A-4 run in reverse albeit poorly and run worse in forward due to the gear ratios. Stalling can be the spark not getting to the right plug due to leaking wires~shouldn't shock you through insulation.

Also if the carb is weak due to poor fuel or being gummed up it may idle sorta, power up a bit in reverse (it's a lower gear ratio 1.3:1) and flat out stall in forward due to the bigger load of the 1:1 forward gear.

I don't think it is the trans adjustment stalling the engine, it just may exasperate the above due to the slipping which is less of a load.

Dave Neptune

[Don Moyer]

The only case I can recall in the last 30 years where a transmission ever caused an engine to lug down when engaging forward was when a local mechanic had inadvertently adjusted the reverse brake band so tightly that it never fully released when going into forward. You can easily check for this possibility by simply checking for a comfortable neutral zone between forward and reverse. Don

[Wavey]

Still stalls in forward or slips backed off one notch.
Exhaust is clear
New wires
Ensured there is a clear neutral and forward detent is reached and also adjusted reverse. Shaft rotates freely in neutral.
While it ran in gear for a few minutes I was able to set distributor timing to max.
I cleaned the carb last week with no difference in running than before...maybe I should take it apart again?
Getting really frustrated

[Al Schober]

Wavey,
Two suggestions: #1 - take a picture of what you're adjusting (hopefully it's the right thing) and post it, and #2 - disconnect the shaft coupling (3 bolts) from the transmission and slide it back a 1/4 inch. Try it there with no shaft/propeller and see what happens. You may have something strange going on.

[Wavey]

I am adjusting the notched collar for forward and the 3/4in nut for reverse. I have ensured prop shaft turns freely in the neutral position.
I can undo my shaft coupling as suggested. Not sure what would bind at higher speed rotation? Packing slipping? Cutlass bearing wouldn't constrict in my mind.
I'll give it a try just to isolate powertrain and see what happens.

[roadnsky]

From the FAQ on this site...

What would cause my engine to run with almost no power in forward, while it runs OK in neutral?
It also seems to have more power in reverse than in forward.

This condition is usually the result of low power caused by something that was done incorrectly during recent engine maintenance.
The reason the engine seems to run better in reverse is because the reverse mode has a 1.7 to 1 gear reduction.

Here are some examples of maintenance problems that we've heard about:


Three to five times each year, spark plug leads were found to be installed in an improper sequence following a tune up!
Cylinders 2 and 3 can apparently be reversed, and the engine will run fairly well in neutral, but will have practically no power in forward. According to one caller, his plug wires were reversed for an entire season before he found the cause of his power loss.


Another recent maintenance "oops" involved a minor repair of the exhaust system which required that the manifold be removed. On reinstallation, the old gasket was improperly installed, resulting in intake leaks and very poor power under load. 



Assuming that there was absolutely nothing done to the engine since it was last running OK, check the following areas for potential problems:



1) Check for something hanging on to the prop.



2) Check basic integrity of the engine by a quick compression check.
If compression is weak in two adjacent cylinders, or water is observed in any of the combustion chambers, the head gasket has probably failed.
If compression is "zero" in any of the cylinders, a valve has probably stuck open. If you are using a compression gauge, compression values over 80 psi are considered adequate.



3) Check for proper carburetor function.
Normally, an Atomic 4 will accelerate almost "explosively" as you flick the throttle forward. If there is any hesitation or mild backfiring, a lean condition caused by dirt in the main jet is the most frequent cause.
In most cases, a problem related to a fuel issue will manifest itself in neutral as well as in forward, but in mild cases, a lean condition might be missed in neutral, but will surely show up under load.



4) Check for proper ignition.
As in the case of subtle lean fuel mixtures, there are subtle ignition problems that can show up under load but not necessarily in neutral.
In this category, plug condition is the best indicator. If one plug is noticeably blacker (or oilier) than the rest, look for the relatively few things that can affect only one plug, such as the plug itself, the plug lead, or a cracked distributor cap. If all the plugs are badly fouled, check things that can affect all plugs, such as a loose condenser, badly worn points, shorting coil (or oil leaking from the coil), cracked distributor cap, or a bad coil lead.

Have you made CERTAIN that your plug wires are in the correct firing order as others have suggested?

[JOHN COOKSON]

I haven't seen any report about the spark plugs. What do the spark plugs look like when you remove them? Have you tried new properly gaped spark plugs?


TRUE GRIT

[JOHN COOKSON]

Turning the shaft and prop in neutral is not a good test. You need to get a diver under the boat.
Here's what happened to me:
I knew the engine was running correctly because I warmed up to temperature in the slip be fore shoving off. When I shoved off and put the engine in gear it died. Tried again with a bit more throttle. Couldn't keep it running. Mean while we are drifting sort of playing bumper boat with the other boats in the marina.....Got a tow back to the slip. Fiddled around couldn't come with much in the way of diagnosis (sound familiar?). The shaft turned by hand in neutral. Went down to the boat the next day to work on the boat some more and noticed my diver was near by. He found part of a palm frond wrapped around the shaft/prop.
Here's what was happening: When I put the engine in gear the plan frond was flung outward by centrifugal force stopping the shaft from rotating.When I turned the shaft by hand in neutral the garbage was just hanging loose so the shaft rotated.

TRUE GRIT

[thatch]

One part that has not yet been mentioned but that would create considerable drag, particularly in forward, is a bad thrust bearing at the back of the reversing gear. These do not often fail, and I imagine that it would make a considerable racket while dying. If you feel some roughness while hand turning the coupling, it could be that bearing.
Tom

[Wavey]

Thanks everyone. Over the past week I have replaced the plugs, wires and coil and set the trans multiple times. Last night I separated the coupling and she ran like a top!
It is my stuffing box without a doubt. In neutral it turns freely which was fooling me. The packing is obviously loose and rotating/binding under power.
She's a 1973 C&C30. The problem is that the packing nut backs out right up against the shaft flange with no room to dig out or install packing! Jeez. There really isn't enough hose at the stern tube to shorten it. So today I am moving the engine forward on the bed rails and doing a proper alignment then repacking with 3/16 flax. All should be good and I will report back confirming my success or unlikely failure.

[sdemore]

Wavey, I just repacked my C&C 30 stuffing box (first time I've ever done one) and had the same problem. Fortunately, my engine wasn't in the boat at the time, but I still didn't have room to slide the nut up with the coupling there and it isn't coming off. I was able to pull the prop and shaft out enough to get an inch or so of clearance and use a small (2 or 3") punch to dig out the old packing. It was a pain, but I cant imagine moving the engine being easier and you still have the coupling to deal with.
Steve

[Wavey]

Originally Posted by sdemore

Wavey, I just repacked my C&C 30 stuffing box (first time I've ever done one) and had the same problem. Fortunately, my engine wasn't in the boat at the time, but I still didn't have room to slide the nut up with the coupling there and it isn't coming off. I was able to pull the prop and shaft out enough to get an inch or so of clearance and use a small (2 or 3") punch to dig out the old packing. It was a pain, but I cant imagine moving the engine being easier and you still have the coupling to deal with.
Steve

You can't imagine? When I move my engine forward while the packing gland is still clamped to the stern tube, I will gain all the access room I need...about an inch, maybe more.

[sdemore]

I was just saying that I couldn't imagine it being EASIER. I just mounted the engine last weekend and it was a bear to get in and align. Taking the clamps off the tube and pulling the prop back was a fairly easy way to get my inch.

[ndutton]

Occasionally we see installations with very little shaft exposed making stuffing box maintenance difficult. Gotta wonder what the builders were thinking. I'm not a big fan of them but in such a situation I'd consider one of the PSS or LasDrop shaft seal products. They don't have packing to replace.

[Wavey]

Problem solved, thanks everyone. Hooked my main sheet to lifting ring and my mast, loosened the mounts and slid her 1.5 in forward. Dug out a single piece of quarter inch packing and replaced with 3 pieces of 3/8 packing. Realigned the motor and all seems well for now.

[JOHN COOKSON]

Originally Posted by Wavey

Problem solved, thanks everyone. Hooked my main sheet to lifting ring and my mast, loosened the mounts and slid her 1.5 in forward. Dug out a single piece of quarter inch packing and replaced with 3 pieces of 3/8 packing. Realigned the motor and all seems well for now.

Good show. Problem handled in a true Afourian manner.

TRUE GRIT

[sastanley]

Wavey, did you use the graphite stuff? Mine barely drips at all now. Thanks for following up..5 years from now someone else will see your post and our ramblings and maybe be able to do a similar fix.

[Wavey]

Well, to be humble...I haven't fixed it yet.
Done so far:
Cleaned carb. Has fixed main jet
Cleaned points, contacts in cap for coil and plugs
New silicone wires
New coil
New NGK plugs gapped .035
New packing, shaft turns freely
Compression check forward to aft from flywheel-95,97,102,101
Removed exhaust gooseneck- clear
Removed water lift exhaust- clear
NOW...
With insufficient forward power it will run with constant throttle attention...rpms will climb and I throttle back, runs there for 20 seconds or so then gets laboured and needs more throttle. Constant fiddling with throttle but I can keep it running in forward and reverse but not enough thrust as mentioned.
So down I go and adjust forward ONE notch clockwise and the gollygeegoshdarn thing stalls immediately after forward engagement.
This is just nuts guys. What did I miss? I'm ready to bolt my Garelick lift and trusty Johnson on the back! Ugh, grrrr
Thanks in advance

[ndutton]

Wild guess but I'm wondering about timing and even possibly firing order. The firing order is easy to check.

As I read through your symptoms I couldn't help but correlate the increased RPM with the distributor timing advance system. It sounds to me like your timing might be improperly set on the retarded side.