Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Introductions

Reply
 
Thread Tools Display Modes
  #1   IP: 104.175.57.64
Old 07-29-2020, 01:19 AM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Maybe the gears?

Hi everyone, this is my first request for help here!

I have a 1967 CAL 36 sailboat with an A4.

Engine runs great....in idle even at high RPM (2000) forever.

I've been having a unique issue for the last few years.

When I engage the transmission and raise the RPM to about 1500, it runs great with good power but in about a minute (every time) the RPM starts slowly dropping and if I let it, it will stall.
I can pull the throttle to keep it going until the end of the range of the cable and it will stall...but slowly, gradually.

What i have done so far:
Replaced the carburetor, installed electric fuel pump, new fuel filter and water separator,thermostat, checked fuel hose, tank vent, compression check,
plugs, points....checked the exhaust for restriction and more.
None of the above changes made any difference, it has been stalling the same way, again, slowly, gradually in gear at higher RPM.

From the beginning I had a feeling it might be the trans or the V drive but don't know how to test that?
The shaft was pulled out and the stuffing box and bushings rebuilt but that mad no difference either?

I had mechanics check it out but eventually they leave without having an idea of how to solve this mystery!

I am very curious what I have missed or how I can move forward?
Reply With Quote
  #2   IP: 71.222.36.208
Old 07-29-2020, 10:09 AM
roadnsky's Avatar
roadnsky roadnsky is online now
Afourian MVP
 
Join Date: Dec 2008
Location: Lake Mead, NV
Posts: 2,984
Thanks: 20
Thanked 297 Times in 210 Posts
Welcome to the crew! You're in the right place.

Do you know the condition of your exhaust? Last time it was rebuilt?

Also, let's try a simple test...
Try running with the fuel fill cap OFF to see if you get the same results.
__________________
-Jerry

'Lone Ranger'

1978 RANGER 30
Reply With Quote
The Following User Says Thank You to roadnsky For This Useful Post:
outoftheblue (07-31-2020)
  #3   IP: 165.225.38.132
Old 07-29-2020, 10:58 AM
Surcouf's Avatar
Surcouf Surcouf is offline
Senior Member
 
Join Date: May 2018
Posts: 239
Thanks: 156
Thanked 49 Times in 46 Posts
do you have a pressure gage on the fuel supply just before the carburetor? That would allow to rule out all fuel tank / fuel pump / fuel filters / air ingress issues.

When the engine rpm slows down, have you tried to spray start-pilot on the carb? If the rpm does not change much and keeps going down, it would suggest that fuel supply if adequate, and that engine is not starving fuel.

I recommend also to verify what Jerry mentioned before, regarding exhaust pressure: do you have a exhaust lift? direct exhaust like a Catalina 27? Ever checked if there was no exhaust flex hose pipe crumbling on itself? pluggage in the exhasut? The fact that you run a minute stable tend to show that your manifold is likely not plugged, as it would not even run one minute. But could be a poorly working water lift due to flow restrictions?

anyway, you will find on that forum a few individuals that love these kinds of hard to find issues, especially as you seem to have already been checking quite a few things...
__________________
Surcouf
Almost There - Catalina 27 (1979)

Last edited by Surcouf; 07-29-2020 at 11:16 AM.
Reply With Quote
The Following User Says Thank You to Surcouf For This Useful Post:
outoftheblue (07-31-2020)
  #4   IP: 155.186.124.219
Old 07-29-2020, 11:07 AM
Dave Neptune Dave Neptune is online now
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Lake Arrowhead Ca.
Posts: 4,250
Thanks: 488
Thanked 491 Times in 340 Posts
If it is in the trans as you suspect the resistance necessary to stall would create a good deal of heat. Is the trans area much hotter than the engine block? This is a very doubtful cause of stalling.

When it stalls does it just slowly come to a stop or does it shake a shudder a bit when stopping?

I suspect it is fuel related and a pressure gage would answer that if just a few minutes.

Did you do any checks once stalled like spark?

Dave Neptune
Reply With Quote
The Following User Says Thank You to Dave Neptune For This Useful Post:
outoftheblue (07-31-2020)
  #5   IP: 155.186.124.219
Old 07-29-2020, 11:10 AM
Dave Neptune Dave Neptune is online now
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Lake Arrowhead Ca.
Posts: 4,250
Thanks: 488
Thanked 491 Times in 340 Posts
Oops

Oops I forgot to welcome you to the MMI Afourian Forum.

Dave Neptune
Reply With Quote
The Following User Says Thank You to Dave Neptune For This Useful Post:
outoftheblue (07-31-2020)
  #6   IP: 47.142.137.42
Old 07-29-2020, 11:24 AM
JOHN COOKSON JOHN COOKSON is online now
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,217
Thanks: 39
Thanked 623 Times in 468 Posts
IT COULD BE, IT COULD , IT COULD BE..........

Once the engine starts pull wire off spark plug. If the engine runs better on three cylinders it could be a exhaust system problem.

Rig up a auxiliary fuel tank directly to the fuel pump, bypassing the boats part of the fuel system. It could be a blockage in the pickup tube in the fuel tank or a blocked filter. Run the electric fuel pump straight from the battery. It could be something in the wiring circuit to the fuel pump.
Does choking the engine the engine help? It could be something weird in the carburetor.

Report back with the result of these tests. We'll tell you what to do next.

Others will have other approaches and ideas. Consider them also.

As noted a fuel pressure gauge would be a useful diagnostic tool.

ex TRUE GRIT
Reply With Quote
The Following 2 Users Say Thank You to JOHN COOKSON For This Useful Post:
outoftheblue (07-31-2020), Sam (07-29-2020)
  #7   IP: 47.142.137.42
Old 07-29-2020, 11:37 AM
JOHN COOKSON JOHN COOKSON is online now
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,217
Thanks: 39
Thanked 623 Times in 468 Posts
MORE FREE ADVICE

Quote:
Originally Posted by outoftheblue View Post
Hi everyone, this is my first request for help here!
I had mechanics check it out but eventually they leave without having an idea of how to solve this mystery!
?
DITCH THE MECHANIC!!!! "Mechanics" are for the most part are a waste of time and money for an A4.
You have several tests mentioned so far in this thread. Report back with the results. Your engine will run correctly. No ifs, ands, or buts.

ex TRUE GRIT
Reply With Quote
  #8   IP: 47.142.137.42
Old 07-29-2020, 03:48 PM
JOHN COOKSON JOHN COOKSON is online now
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,217
Thanks: 39
Thanked 623 Times in 468 Posts
Quote:
Originally Posted by Dave Neptune View Post
If it is in the trans as you suspect the resistance necessary to stall would create a good deal of heat. Is the trans area much hotter than the engine block? This is a very doubtful cause of stalling.
Dave Neptune
Is the prop fouled?
The prop can be fouled and whatever is fouling it sort of stays a ball around the prop at low RPMs and is flung out by centrifugal force at higher RPMs causing the engine to stall. (Don't ask how I know this.)
Maybe the reason neither you or the "mechanic" could not find the engine problem because there is no engine problem?

ex TRUE GRIT
Reply With Quote
The Following User Says Thank You to JOHN COOKSON For This Useful Post:
Ando (07-29-2020)
  #9   IP: 24.15.42.198
Old 07-30-2020, 09:41 PM
Sam Sam is online now
Afourian MVP
 
Join Date: Apr 2010
Posts: 161
Thanks: 97
Thanked 58 Times in 47 Posts
Well, you have an impressive list of work done with replacements etc. I also vote for the installation of a liquid filled 0-15ps1 fuel pressure gauge and fitting between the carb and fuel pump [total about $35]. So far you have received a lot good logical advise and I would like to hear the results of running off an auxiliary tank. With a 1967 Cal 36 you have an early model A4 with the small Prestolite distributor [condenser screwed on outside]. If you would like to humor me pull the points plate from the distributor and check the springs and advance weights for proper function, even change springs [moyer] if they are original. Also, the little screw that holds/grounds the condenser may not be original and if the threads are a little too long they penetrate the housing wall and mess up the mechanism.

I have a friend with a restored 31 Chevy with a simple distributor with a manual cabal advance. The cable slipped and wasn't advancing the timing. The engine ran fine in neutral but bogged down under load [going up small hill etc]
Reply With Quote
The Following User Says Thank You to Sam For This Useful Post:
outoftheblue (07-31-2020)
  #10   IP: 104.175.41.45
Old 07-31-2020, 07:38 PM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by roadnsky View Post
Welcome to the crew! You're in the right place.

Do you know the condition of your exhaust? Last time it was rebuilt?

Also, let's try a simple test...
Try running with the fuel fill cap OFF to see if you get the same results.
Hi, thank you for responding. Glad to be here!
I actually removed the whole exhaust system and tested it. it was clean.
i also had the engine run with the cap off.
Reply With Quote
  #11   IP: 104.175.41.45
Old 07-31-2020, 07:41 PM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Surcouf View Post
do you have a pressure gage on the fuel supply just before the carburetor? That would allow to rule out all fuel tank / fuel pump / fuel filters / air ingress issues.

When the engine rpm slows down, have you tried to spray start-pilot on the carb? If the rpm does not change much and keeps going down, it would suggest that fuel supply if adequate, and that engine is not starving fuel.

I recommend also to verify what Jerry mentioned before, regarding exhaust pressure: do you have a exhaust lift? direct exhaust like a Catalina 27? Ever checked if there was no exhaust flex hose pipe crumbling on itself? pluggage in the exhasut? The fact that you run a minute stable tend to show that your manifold is likely not plugged, as it would not even run one minute. But could be a poorly working water lift due to flow restrictions?

anyway, you will find on that forum a few individuals that love these kinds of hard to find issues, especially as you seem to have already been checking quite a few things...
Thank you,

I have checked the exhaust and it has a great water flow out the exhaust pipe.
Reply With Quote
  #12   IP: 104.175.41.45
Old 07-31-2020, 08:03 PM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by JOHN COOKSON View Post
Once the engine starts pull wire off spark plug. If the engine runs better on three cylinders it could be a exhaust system problem.

Rig up a auxiliary fuel tank directly to the fuel pump, bypassing the boats part of the fuel system. It could be a blockage in the pickup tube in the fuel tank or a blocked filter. Run the electric fuel pump straight from the battery. It could be something in the wiring circuit to the fuel pump.
Does choking the engine the engine help? It could be something weird in the carburetor.

Report back with the result of these tests. We'll tell you what to do next.

Others will have other approaches and ideas. Consider them also.

As noted a fuel pressure gauge would be a useful diagnostic tool.

ex TRUE GRIT
Thank you!
I have ran the engine from a spare tank, connected to the electric fuel pump, no difference but I will repeat because vaguely i rememeber that it ran longer before slowly running out of power but eventually it slowly stalled.
i will repeat the spark plug test but it ran worse on three as far as I remember? I will repeat that.
Chocking, I will ave to try that.
I will test fuel pressure when i get a gauge for that.
Reply With Quote
  #13   IP: 104.175.41.45
Old 07-31-2020, 08:06 PM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by JOHN COOKSON View Post
Is the prop fouled?
The prop can be fouled and whatever is fouling it sort of stays a ball around the prop at low RPMs and is flung out by centrifugal force at higher RPMs causing the engine to stall. (Don't ask how I know this.)
Maybe the reason neither you or the "mechanic" could not find the engine problem because there is no engine problem?

ex TRUE GRIT
Interesting idea!
I have a two blade folding prop but it is clean.
This stalling issue has been a problem for a long time and boat gets cleaned monthly. It would shake i think when it is off centered?
Reply With Quote
  #14   IP: 104.175.41.45
Old 07-31-2020, 08:11 PM
outoftheblue outoftheblue is offline
Frequent Contributor
 
Join Date: Apr 2020
Posts: 6
Thanks: 6
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Sam View Post
Well, you have an impressive list of work done with replacements etc. I also vote for the installation of a liquid filled 0-15ps1 fuel pressure gauge and fitting between the carb and fuel pump [total about $35]. So far you have received a lot good logical advise and I would like to hear the results of running off an auxiliary tank. With a 1967 Cal 36 you have an early model A4 with the small Prestolite distributor [condenser screwed on outside]. If you would like to humor me pull the points plate from the distributor and check the springs and advance weights for proper function, even change springs [moyer] if they are original. Also, the little screw that holds/grounds the condenser may not be original and if the threads are a little too long they penetrate the housing wall and mess up the mechanism.

I have a friend with a restored 31 Chevy with a simple distributor with a manual cabal advance. The cable slipped and wasn't advancing the timing. The engine ran fine in neutral but bogged down under load [going up small hill etc]
Thank you, I think checking fuel pressure will have to be done.
On the other hand, originally I had a mechanical fuel pump when this problem started.

I replaced it with the electrical and it had no effect on it. Engine still slowly, gradually lost power after abut a minute in gear sarting at 1500 rpm.
Reply With Quote
  #15   IP: 47.142.134.119
Old 08-01-2020, 01:29 AM
JOHN COOKSON JOHN COOKSON is online now
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,217
Thanks: 39
Thanked 623 Times in 468 Posts
THOUGHT OF ANOHER POSSIBLE CAUSE

After a shutdown check the temperature of the stuffing box with finger or a IR thermometer.

My posts R\E this problem are sort of disjointed I guess. My subconscious is working on the problem. When something pops up in my conscious mind I post. At least I think so.

ex TRUE GRIT
Reply With Quote
  #16   IP: 207.32.169.48
Old 08-01-2020, 12:47 PM
capnward's Avatar
capnward capnward is offline
Afourian MVP
 
Join Date: Aug 2012
Location: Deer Harbor WA
Posts: 260
Thanks: 19
Thanked 83 Times in 65 Posts
ah, the mystery...

Since it runs fine in neutral, I doubt this is a fuel restriction, but a fuel pressure gauge couldn't hurt. The way I understand it, if pressure goes down as it bogs down, you have a restriction upstream of your fuel pump.
Also, check the advance weights in the distributor. They could be rusted up and not moving well. Is your choke opening properly? If it stays closed that will also cause the engine to bog down. You may be running too rich. Stuck advance weights keep it from running leaner, if I'm not mistaken.
Reply With Quote
The Following User Says Thank You to capnward For This Useful Post:
Surcouf (08-03-2020)
Reply

Tags
stall in gear, transmission, v-drive

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Swapping reverse gears rhodes32 Introductions 2 09-13-2017 11:20 PM
accessory drive gears nyiftos General Interest 3 07-27-2014 09:59 AM
Removing Gears and Shaft Amphibiographer Reversing Gear 4 07-26-2013 06:05 AM
Shifting gears Kemp Dawson General Interest 3 10-22-2008 07:34 AM
broken crank but good gears free to a good home adab1402 General Interest 1 04-26-2008 10:50 PM


All times are GMT -4. The time now is 11:37 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2020, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2020 Moyer Marine Inc.

All Rights Reserved