[AT] Allis Chalmers B Question

[john hall]

 I haven't followed all of this thread so I'll add my $.02 with apologies 
regarding any info that I am repeating. You mention the plugs are firing, 
that is no sign the mag is hot enough. Any magneto should be able to fire 
the spark across a 1/4" gap. That is considered a minimum--a lot of "newer" 
mags can hold 3/8-7/16 of spark. Take an old spark plug and open up the 
spark gap wide (no more than a 1/4"--try in increments of 1/16") can and see 
if the mag can jump that gap.
 I missed your original post so I am not certain about what suggestions to 
throw out. Is this a running tractor that now refuses to crank or is this a 
machine that has been taken all apart for a rebuild. If it was a running 
machine, I'd just think you have lost fire or fuel, can't see it being much 
else unless it has been sitting for many years and the compression is low. 
If it is a rebuild project, the list of re-assembly errors is long.
If you don't get it cranked, re-post some background info on the machine 
(I've already dumped the old posts).

Good Luck,
John Hall

----- Original Message ----- 
From: <Recentjester at aol.com>
To: <at at lists.antique-tractor.com>
Sent: Saturday, April 02, 2011 12:11 AM
Subject: Re: [AT] Allis Chalmers B Question


> plug is dry it is overhead valve an it is pullin a vacumn on  my hand at
> the carb throat. gas is runnin out the carb. Valves are all moving  fine.
> grounded plug with it out of the hole nice blue spark (an on all the  rest 
> as
> they go around, I checked them all) I am on compression stroke felt  the
> pressure an both intake and exhaust are both closed on #1 #4 is on 
> exhaust.  not
> even a pop an tried ether.
>
>
> In a message dated 4/1/2011 5:33:31 P.M. Central Daylight Time,
> 1cdevill at gmail.com writes:
>
> On Fri,  Apr 1, 2011 at 4:33 PM,  <Recentjester at aol.com> wrote:
>>  Welllll I been crankin this allis B to no avail. I even tried  ether no
> pop
>> even. The mag is set so that It clicks on #1 while the FIRE line  is  in
> the
>> middle of the timing hole on the flywheel. fireing  order is correct 
>> vales
>> are set correctly 0.10 loose have gas to carb  an its clean. I have never
>> cranked  one before an must confess I  am maybe erring on the side of
> caution.
>> Have an old  Harlie an  have been kicked.
>
>
> Back to basics my friend.
>
> Remove #1  plug.  Is it wet or dry??
> Wet- No spark or just flooded.
> Dry- find  out why fuel is not drawing into the cylinder.
>
> Ground the plug base and  crank the engine to verify spark at the plug 
> tip.
>
> Disable the other  three plugs.  Crank the engine with finger on #1
> plug hole until you  feel compression building.  Make sure mag snaps at
> the top of that  stroke to confirm it is not 180 degrees out.
>
> Good luck.
>
> Charlie  V.
>
>
>>
>>