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Message |
    
Barry Millar
Senior Member
Username: bcm
Post Number: 74
Registered: 11-2009
| | Posted on Wednesday, August 10, 2016 - 09:37 pm: | 
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About 10 years ago a web site was prepared to provide technical Information for Paul, who completed a magnificent restoration of a 1913 Mullins Launch. Paul installed a 4HP St Lawrence two-cycle engine, having neither prior experience nor understanding of engines of this vintage and style, thus experienced major operational issues.
The site is no longer web published so as a service to members who are using or restoring a two-cycle marine engine, I’ve printed subjects that provide useful information. As these were written for web publishing the images are not high quality when printed and scanned and the animation is not functional. Hopefully the content is legible. Unfortunately many of the external links are no longer available.
The web site comprised 14 SUBJECTS
This post covers:
SUBJECT 13 – Schebler Model D Carburetor – Maintenance and Repair
Barry Millar
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Robert
Senior Member
Username: robert
Post Number: 729
Registered: 07-2003
| | Posted on Saturday, August 13, 2016 - 04:41 pm: |
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I believe that must be the best Schebler D info yet published; certainly the best illustrations. |
Ernie
Senior Member
Username: ernie
Post Number: 2297
Registered: 01-2002
| | Posted on Sunday, August 14, 2016 - 07:06 am: |
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Some additional notes
Schebler Model D carbs ONLY use 1 gasket.
This is the one in the center and can be a gasket or an O Ring.
Be careful using an O Ring as some seem to fit but when installed they will bulge out into the throat of the carb. 1 and 1/4 inch carbs are the ones that do this the easiest.
The gasket that was originally in the cover over the float needle valve should not be used even though there may be the remains of one there.
This is because at this point in history the carb may be a combination of parts from other carbs. The float bowl does need to be vented. Due to a combination of parts this may no longer be the case. Leaving this gasket out will vent the float bowl.
When I rebuild a Model D if it doesn't have the float tickler that was originally intended to flood the carb for cold starting I drill a 1/16 hole in the carb top where the float tickler would have been if it isn't already drilled.
Even when making sure the float bowl is vented I still don't put a gasket on the small cover. They don't leak there unless the float level is way too high.
The float tickler also vented the float bowl.
Schebler never used a gasket between the throttle and carb body/float bowl.
From looking at dozens of Schebler throttles they are almost always warped. Just use sand paper on a sheet of glass and sand the mounting surface flat. Make sure to clean the throttle body out well after this. Especially up in the area that the throttle plate goes during wide open throttle.
Your engine will now most likely idle better as well. |
Robert
Senior Member
Username: robert
Post Number: 848
Registered: 07-2003
| | Posted on Wednesday, March 22, 2017 - 11:02 am: |
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Is that perhaps why no gasket was used around the outside edge of the bowl originally: to provide some venting?
And of course if your carb is sitting nice and square to the engine when it sits on level ground, consider what angle the carb will be at when the engine is (hopefully!) aligned to the prop shaft?
Ernie can you comment on wear to the needle valve tip and seat and what if anything can be done about that? I suppose rebuilders had a cone tip reamer to recut the seats? |
Ernie
Senior Member
Username: ernie
Post Number: 2375
Registered: 01-2002
| | Posted on Wednesday, March 22, 2017 - 05:30 pm: |
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Robert
I use a viton needle and seat from some sort of a small OMC outboard. No sorry I don't know the part number.
How I did it is in the section on my Rose style launch.
To use the needle and seat that came with the carb well ummmm ahhhh hmmmmm
I just put it back in and they seem to work.
On show engines I have adjustable height on my fuel tank so the available fuel pressure is only enough to fill the carb.
More info from Barry here
http://www.oldmarineengine.com/discus/messages/3433/101261.html |
Timothy Leigh
New member
Username: timoteo11
Post Number: 1
Registered: 11-2017
| | Posted on Monday, November 20, 2017 - 04:25 pm: |
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We have a 25 cu. in. Palmer YT-l marine engine that needs a 3/4" Schebler Model D carburetor. Anybody know where we can find one? |
shaun holden
New member
Username: putty
Post Number: 1
Registered: 02-2022
| | Posted on Saturday, May 07, 2022 - 03:29 am: |
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Bang on the money with all that good info, I have 3 complete model D carbs, now I know the difference between a new and used float valve and straps and fuel level and venting. Thank you. |
Chris Spring
Senior Member
Username: chris_spring
Post Number: 202
Registered: 02-2019
| | Posted on Saturday, May 07, 2022 - 11:12 am: |
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Shaun.
This place holds a wealth of information. I would never have been able to get as far as I have in my projects without the help and advice of those hanging out here.
Often the site is not busy, but if you have a question, and you bring it here, you will soon find you've come to the right place.
Cheers! |
