Instant stall when put in forward.

[anglosax]

oil change

get a vacuum extractor and stick the thin tube down the dipstick hole while the engine is hot. get out all you can and then remove the transmission cover and use the thicker tube to get the remainder left in the reversing gear. If you are very particular, use a flushing oil and repeat

[anglosax]

Hmmm

Smooth
Rereading your initial post check that there is no wiring being moved or pinched by the transmission linkage - when you say it wont start in fwd gear do you mean it wont crank or wont fire ?

[anglosax]

Hmmm 2

Can you turn the propshaft by hand when in neutral ? what happens if you put into fwd gear at 1000 rpm or throttle up hard immediately after hitting FWD

[ndutton]

Smooth,

Please keep a watchful eye on the oil level and its smell. In an earlier post you said the oil level was 1 1/2" over the full line on the dipstick (that's a lot) and it smelled of gasoline. I haven't read anything since where those issues have been addressed so I would expect them to return.

[sastanley]

+1 what Neil said. This is an assumption you have a mechanical fuel pump..what year is your boat and A-4? (all original parts?) Fuel pump rebuild kits are available here at Moyer..mine was about a two cups of coffee rebuild on a Sunday morning.

Most A-4's get an oil change by sucking out of the dipstick hole, or the reversing gear cover. This is not too bad with a C-30 except for the counter top hindering rear engine access.

I cut the area of the settee board that extends past the counter top on my C-30 for better access (over top of the coil/dipstick/distributor area) You will need to support the counter top however with a piece of angle or similar. Neil has a great pic of his boat's modification that works well.

What if you put in fwd and add choke before throttle up? Will it keep running?

[SmoothSailor]

Answers for AngloSax

1. No wiring being pinched by transmission linkage that we can see.

2. We can turn shaft when in neutral, but still quite difficult.

3. If we throttle up quickly after shifting into neutral engine will stall.

Current status.
1. Gas In Oil. Most likely cause appears to be leak in diaphram in fuel
pump. (from other threads on this forum)
Moyer sells a rebuild kit for mechanical fuel pumps.

2. Black & Sooty plugs. Excessive back pressure from exhaust ?

3. Stalling when throttle applied in forward. This seems to be fuel
problem or transmission adjustment. (The only time we tried to start
the engine while in FWD, nothing happened, not even a tick or click.)
When in neutral or even reverse engine will start immediately.

General Info.
Boat = 1982 Catalina 30
Engine = Original Atomic 4, Serial #283723
Fuel pump is mechanical, would assume original.

[anglosax]

hmmm3

Smooth
Stupid question - is there a neutral safety switch in the tranny linkage somewhere. Ive never seen one on an A4 but......
Everyone else seem to think fuel problem [ and they may be right][ certainly the fuel pump needs attention ] but electrical fits the symtoms more although nothing points to a smoking gun -
You could bypass the fuel pump temporarally with a rubber bulb pump and see if it makes any difference but I doubt it
we need Don on this one!!!hes always right

[Marian Claire]

Have you visually checked the position of the choke valve? This is more of a question than answer but could a closed choke allow it to run at low RPMs and cause the engine to die when revved up? Not enough air? Black and sooty, rich condition?? Dan S/V Marian Claire

[sastanley]

smooth..it should still run with a clogged exhaust..you should visually check the exhaust.

My 1977 had failing exhaust hoses..near the transom and near the water lift muffler. Sometimes they collapse internally and mimic a clogged exhaust.

The exhaust mixer is the place to check for clogged exhaust...mine is directly under my inboard sink.

[SmoothSailor]

Video of abrupt stall in forward - Youtube.

I am uploading a video of the transmission area of the engine. It is rather long so be patient. At the 2.5 minute mark the throttle is increased and shortly after you can see the abrupt and instant stop of the shaft.

http://www.youtube.com/watch?v=bR-jnXKiPK8

We have not visually checked the position of the valve, we can check this on Friday.
(Unfortunately we are a 2 1/2 hr drive, plus one border crossing away from the boat during the week)

[JOHN COOKSON]

Smooth

How hot is the stuffing box\packing gland right after the shut down? Put your finger on it and check. Be careful.

TRUE GRIT

[TomG]

Smooth,

As a disclaimer, I know very little of the particular inner workings of the A-4. I understand in theory how 4-stroke engines work (and 2-stroke and gas turbine for that matter), but nailing down the specific set of symptoms you have is not my forte'. That said, I noticed many similarities between your problems and this thread: "Engine full rpm neutral but dies in forward"

Specifically, this post on that thread is the "Eureka!" moment.

Problem solved

Hanley Clifford wins the pretend trip to Hawaii!
Mike D. pulled the boat last Saturday in Camden - said Apprenticeshop school ramp in Rockland was difficult w no floats - as I thought I must have something wrapped on the shaft.
So there was nothing on the shaft, so I repacked the stuffing box and the old flax packing was fine.
So rule those out.
He relaunched then worked on it for awhile, in water at dingy dock, and I was glad to get another set of eyes on it.

How much can go wrong with a tractor engine??....
He finished, started engine, ran great in neutral, died in gear.
He was stumped, got mad, and said the boat needed an enema.
I thought about it, and What Hanley had said in his blog reply, and then took them both literally.

I shoved a 9' piece of stiff thickwalled plastic tubing in and up the tailpipe. Went in easily enough about 4 feet then was very hard to get the rest of the way in. pulled it out and it was covered with a bag of rags worth of black tar goo. So I figured maybe he was onto something in that I confirmed there was an obstruction in the exhaust which would result in excessive backpressure under load and stall the motor. Collapsed internally, whatever.
I called Don Moyer who agreed and told me to disconnect the exhaust pipe at the manifold, drop it down and also to run the cooling water discharge to the bilge, so I did. A little loud and smoky but the engine ran great and came up to speed in gear w no flat spots or stalling. Imagined lots of CO in the cabin even with fwd hatch open wide, so took a lunch break before repeating test.

So I ordered an new wet muffler system from Moyer Marine and the other parts needed to build a new exhaust system. Very hopeful now.
Looking forward to a trip further downeast next week.
Enjoy the pretend trip to Hawaii, Hanley. I remember in another lifetime sailing from the Aliwai marina across the Lanai channel for a Luau at Lanai.
This time of year Maine is better! Enjoy the rest of the season! Doralda

If the new fuel pump does not cure the problem, an exhaust system blockage or restriction might be considered.

I offer this as well: My boat had similar issues when I got her. I was very fortunate that the boat had a nearly brand new MMI rebuilt A-4, so engine issues where towards the bottom of the "likely culprits" list. Although the boat had been re-powered, the exhaust system had not been updated. Preparing to replace the old exhaust system over the winter, I discovered a collapsed exhaust hose. It wasn't really obvious from the outside... it just seemed a little softer in one spot. When I removed the old water lift, here is what the cross section of the exhaust looked like:



As you can see, precious little exhaust was getting by this restriction. It doesn't take much load on the engine before it can't overcome the increased back-pressure and the torque of the prop.

Best of luck and let us know how it goes!

[SmoothSailor]

Some recent pictures (5 total)

Coil has been replaced since pics were taken.

[Dave Neptune]

Stop stop stop!!!

Smooth, that was not a fuel or electrical shut down on the video it was mechanical. Something is either binding or jamming in the trans or it would "coast" to a stop, this is sudden and not good.
Get the cover off the trans and poke around, could be a planetary jamming or perhaps something is getting sucked off the bottom and jaming the mix.
Have you tried to move the P-shaft imediately after it stops??

Dave Neptune

[SmoothSailor]

Stop, stop and stop.

Dave, we tend to agree about something mechanical stopping the shaft.
We have suspected the trans needs adjustment. In response to your question about turning the shaft after stoppage. No chance, it will not turn.
If trans is shifted into neutral we can turn it but it is still quite stiff. Not sure what you mean re "planetary jamming"
We had the cover off for most of last weekend. Oil has been changed three time to get rid of the gas. We did not see anything that might jam the trans.
I should point out if the throttle is left at low RPM (even in forward) it will not stall/stop.

We also believe the fuel pump needs to be rebuilt, (gas in oil etc.) but probably has nothing to do with sudden stop of shaft.

Tom,
We are going to check the exhaust this weekend, I don't know very much about the exhaust system for A4 and Catlina 30. I will have to brush up this week.
I won't be suprised if it needs some attention.

Kirk