Wha Hoppened??

Farmall Cub Forum -- Questions and answers to all of your Cub related issues.

Moderator: Team Cub

Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.

Wha Hoppened??

Postby Dusty B » Wed Jan 09, 2013 3:24 pm

OK, need help! Katrina started and ran fine last fall, crank start, magneto all same as last time. Sat over the winter, now when I crank it over get a loud backfire thru the exhaust !??? First reaction was it is out of time but nothing has been changed since the last time it ran?? Suggestions on where to start??? Thanks, Dusty B
Grandpa's '41 B
'56,,'57,'59,'71 Cub
'51 Super C
'55 Case SC
Fairbanks-Morse 3KW Generator
Dad's DB garden tractor
'48 DeSoto
'31 "A Coupe
'51 Ford PU
'55 Dodge PU
God looks out for those of us who don't know how to look out for ourselves!
User avatar
Dusty B
501 Club
501 Club
 
Posts: 1273
Joined: Wed May 23, 2007 7:35 am
Location: IL, Downs
Zip Code: 61736
Tractors Owned: '45 SC Case
Fairbanks-Morse Generator
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby Bill Hudson » Wed Jan 09, 2013 3:34 pm

Dusty,

Not an expert, by any means, but I would suspect moisture in the distributor cap. Wipe it out good and see if that makes a difference.

Bill
"The probability of life originating from accident is comparable to the probability of the unabridged dictionary resulting from an explosion in a printing shop." Edwin Conklin, biologist
Bill Hudson
Team Cub
Team Cub
 
Posts: 6244
Joined: Wed Jul 26, 2006 10:50 am
Location: OH, Madison
Zip Code: 44057
Tractors Owned: :
57 F-Cub
64 Lo-Boy
68 Lo-Boy
52 F-Cub
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby 64/67lo-boy » Wed Jan 09, 2013 3:45 pm

what about an exhaust valve that mey be stuck open?
Pete from Virginia Beach


man comes into the world cold naked wet and starving, and after that things get worse. "Gun Smoke"
User avatar
64/67lo-boy
Cub Star!!
Cub Star!!
 
Posts: 266
Joined: Sun Nov 23, 2008 2:46 pm
Location: Virginia Beach
Zip Code: 23453
Tractors Owned: 48 cub
67 loboy
52 super c
74 loboy 154
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby Jim Becker » Wed Jan 09, 2013 3:52 pm

Do you get a good loud click out of the impulse coupling each time it should fire? A sticking coupling can cause some bad timing behavior.
User avatar
Jim Becker
Team Cub
Team Cub
 
Posts: 11853
Joined: Sun Feb 02, 2003 3:14 pm
Location: TX/MN
Zip Code: 75048
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby tst » Wed Jan 09, 2013 3:58 pm

check and make sure the distributor cap is dry inside also
Tim
tst
501 Club
501 Club
 
Posts: 1506
Joined: Tue Jan 12, 2010 2:08 pm
Zip Code: 12514
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby Chris D » Wed Jan 09, 2013 4:10 pm

Ditto to what 64/67 said, exhaust valve not closing properly/sticky valves
Chris D
Cub Star!!
Cub Star!!
 
Posts: 397
Joined: Tue Nov 30, 2010 7:54 pm
Zip Code: 23027
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby lazyuniondriver » Wed Jan 09, 2013 4:36 pm

All 3 of the aforementioned scenarios very possibly causing your grief.

If the impulse snap is late, so will be your spark. This is the easiest to check, all visual by looking at the timing marks and listening for the magneto snap.

Next check that distributor cap for moisture or other defects.

Thirdly, a quick compression test will determine valve operation or lack there of.

I think your diagnosis is correct but the timing affected in a slightly different manner.
"HAVE ALL YOUR DELIVERIES MADE BY UNION DRIVERS"
Image
lazyuniondriver
Cub Star!!
Cub Star!!
 
Posts: 438
Joined: Tue Aug 07, 2012 1:37 am
Location: Southern Suburbs of Cleveland, Ohio
Zip Code: 44134
Tractors Owned: 1949 & 1951 Farmall Cubs

Several Snapper Garden Tractors
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby Dusty B » Wed Jan 09, 2013 6:47 pm

lW/check cap tomorrow! Then on to compression. Thanks, Dusty
Grandpa's '41 B
'56,,'57,'59,'71 Cub
'51 Super C
'55 Case SC
Fairbanks-Morse 3KW Generator
Dad's DB garden tractor
'48 DeSoto
'31 "A Coupe
'51 Ford PU
'55 Dodge PU
God looks out for those of us who don't know how to look out for ourselves!
User avatar
Dusty B
501 Club
501 Club
 
Posts: 1273
Joined: Wed May 23, 2007 7:35 am
Location: IL, Downs
Zip Code: 61736
Tractors Owned: '45 SC Case
Fairbanks-Morse Generator
Circle of Safety Award
Circle of Safety: Y

Re: Wha Hoppened??

Postby Donegal Cub » Wed Jan 09, 2013 7:26 pm

Borrow her Ladyship's hairdryer it's great for drying out the distributer cap etc
Donegal Cub
Donegal Cub
Cub Star!!
Cub Star!!
 
Posts: 327
Joined: Fri Apr 06, 2012 6:30 pm
Zip Code: 00000

Re: Wha Hoppened??

Postby Rick Spivey » Wed Jan 09, 2013 8:23 pm

Points gazed over; just guessing, but possible. clean them up, and try again.
Rick Spivey
'52 Cub ("Great Personality") 148xxx
'48 Cub with FH ("Gunny Cub") 38xxx
'57 Lambretta (a slow work in progress)
'74 Triumph TR6 (Mama's toy)
User avatar
Rick Spivey
Cub Pro
Cub Pro
 
Posts: 1709
Joined: Sun Jul 01, 2007 10:07 pm
Location: SC, Simpsonville 29681
Zip Code: 29681
Circle of Safety Award
Circle of Safety: Y


Return to Farmall Cub

Who is online

Users browsing this forum: Daniel H., ericofmaine, midmo, Tezell, Tim66 and 10 guests