b&s 8.5 hp motor on craftsman snow thrower

Reply

  #1  
Old 12-22-11, 06:30 AM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
b&s 8.5 hp motor on craftsman snow thrower

I cleaned carb,fuel system, I have spark, i get gas on prime,..still wont start...(this was original sympton,as well}...pull cord several times..get a fart..which gets louder the more i prime...I HAve compression on my thumb of some sort....I think ..ohv adj..? timing prob..?...also my friend may have changed plug....reg y19 ...or does it need resistor plug..???? PLEASE GIVE ME SOME ADVISE,,,THANKS
 
Sponsored Links
  #2  
Old 12-22-11, 07:02 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,756
Which engine do you have? The model number should be stamped on it somewhere. We can't give any specific help until we know what engine you have.

Try removing the spark plug and pour 1 teaspoon of gas into the cylinder. Re-install the spark plug and give it several pulls. Does it sputter or try to fire better than it did before adding the gas? If yes then I'd look at the carb. as the source of the problem. Even if you cleaned it there still may be something clogged, improperly set jet or worn out, broken or missing parts.
 
  #3  
Old 12-22-11, 10:46 AM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
The model # is 15a114 0342
 
  #4  
Old 12-22-11, 11:27 PM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
No tried tsp of gas after severel pulls it poped.....tried some start fluid,,,,riped cord 1 time....major backfire,,,2nd,iiii I GOT INTERNAL PROB..
 
  #5  
Old 12-23-11, 05:12 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,756
Do you know if the engine had a sudden stoppage? Running full throttle blowing snow and maybe catch a big rock that stops the engine dead in it's tracks? If so it's possible that the flywheel key is sheered which can get the timing off. In some rare cases (on racing engines) I've seen a back fire strong enough to sheer the key. Remove the flywheel and look at the key that goes between the flywheel and crank shaft. It should be nice and square. If it's broken into two pieces or has a bit of a "Z" profile it needs replacing.

Another easy thing to do is remove the cylinder head. Then slowly pull the starter cord and watch the movement of the piston and valves. You should insure that everything is moving in the proper sequence for the intake, compression and exhaust strokes.
 
  #6  
Old 12-23-11, 06:37 AM
puey61's Avatar
Member
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
This will be an overhead valve engine and the head removal should not be necessary. But! I'll bet you have a valve out of clearance...remove the rocker cover and measure each valve's clearance. Set both at .005".
 
  #7  
Old 12-23-11, 02:10 PM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 17,756
Doh! I even looked at the engine diagram and still had it stuck in my head it was a old side valve.

When you have the valve cover off, remove the spark plug and slowly pull the starter cord. You should see the valves moving hopefully indicating that one is not stuck.
 
  #8  
Old 12-28-11, 05:26 PM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
8.5 b&s

SORRY ITS BEEN A WHILE,,,iI LOOKED AT OH VALVE OPPERATIONS LOOKS O.K. TO ME ....OWNER TOLD ME A NEWS PAPER GOT STUCK IN IT......(THE AUGER)...SINCE THEN IT WOULD RUN 5-10 MINUTES...THEN DIE...UNTIL AFTER SOME TIME IT WOULDNN'T START AT ALL.....LOOKING AT PARTS DIAGRAHM ON THE B&S ..IT SHOWS A TIMING GEAR WITH A KEY INSIDE BUT HAVE TO OPEN MOTER TO CHECK.....ITS ON OPPISITE SIDE OF FLY WHEEL SIDE OF THE CRANK SHAFT...NEED GASKET SET..??? ANY OTHER WAY TO CHECK,,,,,UNLESS IM READING DIAGRAHM WRONGGG....PLEASE ADVISE..
\
 
  #9  
Old 12-28-11, 06:06 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,814
The flywheel key is not inside the engine. You're looking at the crankshaft gear key on the diagram. Look at the big round metal wheel at the front of the engine under the pull rope... this is the flywheel. It has a key that shears. Most likely this is your problem. You don't have to take the engine apart to fix it.
 
  #10  
Old 12-28-11, 07:21 PM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
8.5 b&s

Iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiichecked it....
 
  #11  
Old 12-30-11, 08:55 AM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
they are gaped between .005 & .010 .........................................................................
 
  #12  
Old 12-30-11, 02:44 PM
Member
Thread Starter
Join Date: Dec 2011
Location: usa
Posts: 7
Thanks.................that was it...I was going there first before, taking motor apart
 
  #13  
Old 12-31-11, 05:28 AM
puey61's Avatar
Member
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
What, was it? The key or the clearances...because .010" is way too much for an overhead valve engine.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes