Create an account Home  ·  ·  Forums  ·  ·  Articles  ·  ·  Downloads  ·  ·  Photo Gallery  
Login
Nickname

Password

Don't have an account yet? You can create one here.

Navigation
· Home
· Article Archive
· Article Submit
· Downloads
· FAQ
· Forums
· Members List
· Photo Gallery
· Private Messages
· Web Links
· Your Account

Search Articles



Forums

M170 for sale /part out
rebuilt engine (F134) - what has to be done after running-in
VIN/Title Question
Head water by pass.
Oops What have I done! T-90 Rear Bearing Came Out
Photo Gallery Request
Wiring loom & snorkel
Easylok Hubs
hi kiddzzz, new kid here. M38A1, 52
TM9-1825B

Willys M Jeeps Forums


willysmjeeps.com :: View topic - How to prime the M38A1 carb to help start?
 Forum FAQForum FAQ   SearchSearch   UsergroupsUsergroups   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

How to prime the M38A1 carb to help start?

 
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base
View previous topic :: View next topic  
Author Message
JeepdaddyRC
Member


Joined: Jan 10, 2020
Posts: 37

PostPosted: Tue Jan 19, 2021 8:57 am    Post subject: How to prime the M38A1 carb to help start? Reply with quote

Is it correct that the Carter YS 950S accelerator pump is different and does not give a shot of fuel in the carb throat by depressing accelerator?

In the MB and CJ's a simple shot of gas poured in carb throat would help start a vehicle that had been idle.

If this M38A1 sits a week it is hard to start. Other than using the fuel pump lever to refill the carb bowl (this has no dash priming pump), how do you get an extra shot of fuel into the Carter YS 950S throat to ease starting?
Back to top
View user's profile Send private message
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 15242
Location: Wisconsin

PostPosted: Tue Jan 19, 2021 9:13 am    Post subject: Reply with quote

The civvy carbs use a manually operated accelerator pump that will squirt gas into the carb anytime you pump the pedal. The Military carbs YS637S (M38) and YS950S (M38A1/M170) have a vacuum operated accelerator pump which must have engine vacuum available to operate.

This is why you often see the dash primer pumps which were actually necessary for severe cold weather starting.

The secret to starting the Military carbs is to use full choke which supplies a wee bit of engine vacuum while cranking then pump the pedal a few times. Don't try this for too long cause she'll flood very easily.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
JeepdaddyRC
Member


Joined: Jan 10, 2020
Posts: 37

PostPosted: Tue Jan 19, 2021 9:24 am    Post subject: Reply with quote

Thanks for the quick reply. I am also in WI. So you don't ever pour a shot of gas in the carb throat to make it easier on the battery and starter?

I'm not even sure how you would get a shot of gas around the 90 degree bend in carb unless you use a turkey baster or something similar.

Newbie to the M38A1. Thanks for your patience as I learn.

Why did the M38 and M38A1 use a vacuum operated accelerator pump compared to the MB, GPW and CJ that used a simple manually operated accelerator pump?
Back to top
View user's profile Send private message
4x4M38
Member


Joined: May 30, 2014
Posts: 3127
Location: Texas Hill Country

PostPosted: Tue Jan 19, 2021 4:30 pm    Post subject: Reply with quote

Remember the M38 was the first factory fully waterproof jeep.

I suspect the carb design was to support that.
_________________
Brian
1950 M38
MC11481
http://www.willysmjeeps.com/v2/modules.php?set_albumName=album372&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Powered by phpBB © 2001 phpBB Group
Forums ©

 



PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.