Question for DrAllis
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=40511
Printed Date: 21 Sep 2025 at 4:46pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Question for DrAllis
Posted By: Henry se/k!
Subject: Question for DrAllis
Date Posted: 13 Nov 2011 at 9:15pm
|
Buddy has 4 cyl dis in ac backhoe. Engine was stuck. Rebuilt motor and instaled inj pump at top dead center. Would not start.Look in book, it said 25 deg before tdc. Started well but missed on no 1 cyl. 400lbs comp,changed injector same result, white smoke. Loosen line smoke stops.Could the pump be 1/2 off and still run on 3 cyl? What other things could cause this? Thanks for any information
|
Replies:
Posted By: DrAllis
Date Posted: 13 Nov 2011 at 9:31pm
|
Stick the number one injector in another hole and see if the problem follows it.....I'll bet it does.....400 psi compression with the starter is good.....400 psi with engine running is low.
|
Posted By: Henry se/k!
Date Posted: 13 Nov 2011 at 9:36pm
|
Book says 400 lbs at 600 rpn. Inj works fine in 2 or 3 hole
|
Posted By: DrAllis
Date Posted: 13 Nov 2011 at 9:39pm
|
Then, compression test the other holes and see what they actually are. I'm used to closer to 500 psi on a fresh engine. I also assume this is an Allis engine and not a Perkins?
|
Posted By: Henry se/k!
Date Posted: 13 Nov 2011 at 9:46pm
|
Yes it is the later model with ac engine, Will check other cyl Monday Thanks
|
Posted By: DrAllis
Date Posted: 13 Nov 2011 at 9:49pm
|
Don't know where you got your pistons&sleeves, but there are 14 to 1 and 15 to 1 and 16 to 1 compression ratio pistons....you should be using 16 to 1 on that application and maybe (just maybe) you've got one WRONG piston ?
|
Posted By: Henry se/k!
Date Posted: 14 Nov 2011 at 7:04pm
|
Up date on miss! Checked cam gear that was changed. Casting no was same as old gear but no stamped on out side of gear was different! 1/2 tooth different in placement of keyway. Will find different gear tues.Dont now this would make it miss only no 1. update due after we change gear.
|
|