not a lawn tractor but a snowblower....

All,

Ive got a sears craftman snowthrower that I cannot get running.
Fresh gas, plenty. Float works. When I take the plug out and crank it (120vac). I see spark.

The old theory of suck-squeeze-bang-blow doesn't help me with this problematic machine.

Any help?

D.
 
It would help if you posted make/mod# of eng & if 2 cycle or 4 cycle and sears mod# of blower.

Possible causes of problem,internal passages in carb plugged,air leak at carb mounting gasket,sticking/stuck valve,if ohv eng valves may need an adjust,leaking/blown head gasket,bent/sheared flywheel key changing ign timing,low compression due to cyl/ring wear,broken rod.
 
I apologize for not getting enough info on here.

The engine is on a craftsman snowthrower. It"s a horizontal shaft, 8 hp. 26 inch cut.

model# 536_918400

serial# 9138.

Things I did:
drained old gas, put in new.
New spark plug.
Tried to start with ether- did not pop.
Romoved plug, was wetted with gas.
Placed plug on the head and saw spark, which I thought was weak, but present.

Took compression tester and got it to reaad 115 psi.

Don"t know where to go from here...

D.
 
If the spark is weak the plug may not be firing under compression is this a Tecumseh engine and does it have electronic or magneto ignition? Have you tried pouring some gas in the carb and cranking it?
GB in MN
 
MNGB:

I trie a new plug, which didn't hellp. I don't know if it's atecumseh, there's no markings onthe recils cover.

I believe it's plenty old not to have electronic ignition. It looks that thte electrical is under the flywheel, if that helps.

Thanks for he response,

D.
 
If it has a magneto the points maybe corroded and the condenser could be bad you could try cleaning the points or installing new points and condenser, and see if you get a strong spark.
GB in MN
 
Hi Dennis, yes most of the older engines have the coil outside the flywheel generally at the top and the points and condenser are mount under the flywheel, which requires removing the flywheel to get at them. I can't be more specific with out know the engine make and model, I'm thinking Tecumseh as Sears used them on a lot of their power equipment. On the cooling housing there will be numbers for model etc try locating them.
GB in MN
 
GBMN,
I am sure htere are no umbers on the sheetmetal housing thaat also has the recoil.

I don"t know where else to look.

D.
 
Your snowblower was made by AMF & same/similar to craftsman 26" blower I have(7hp)as mine was also made by AMF,GBMN is correct eng probably a Tecumseh(H80).

Look on side of recoil starter houseing below heat box cover for carb,there should be a craftsman id tag riveted to houseing,stamped in tag will be sears mod# for eng,spec# & sn,if mod# starts with 143 then eng a tecumseh,if mod# starts with 500 then eng a briggs.IF there are only 2 holes in starter houseing below heat box then either rivets broke & tag fell off or someone removed tag,either way it's gone.

This is an old snowblower probably mid 70's-early 80's,the ign may be point type of solid state as there was a change over in above time frame(bought mine used & never had a problem with ign,so I don't know if point type or solid state ign,never had flywheel cover off)remove flywheel cover,you'll probably find coil mounted over flywheel,IF there is a wire going from terminal on coil to under flywheel,then you have point type ign,if only a single wire connected to coil going to key sw on heat box cover then ign is solid state & has no points/condenser.
 
hope these come through...
a113588.jpg

a113589.jpg

a113590.jpg

a113591.jpg
 
Looking at muffler,carb & starter in pics,eng is a tecumseh,it also appears that coil,points/condenser(if eng has)are located under flywheel.

In addition you may have an 18w alternator stator under flywheel,in one pic blk wire coming out of flywheel backplate & going up handle could be for a key sw/stop sw on handle cross bar or an 18w sealbeam lite as I have on mine,I don't know which you have on yours.

In one pic of flywheel cover/recoil starter(bottom view) there are two small holes,this is normally where id tag is located either tag never put on,lost/removed or may have been a decal that's long gone.
 
Joe,

thanks for looking and keeping me in the loop. It does indeed have a headlight.

I guess I"m in for pulling hte flywheel to see what can be seen.

I was thinking of timing, but on a thrower, how would it get off? There"s shear pins, belts to keep the crankshaft from getting jarred and shearing a key?

I am stumped on this, but appreciate all the help.

D.
 
The ign timing is determined by position of flywheel on crankshaft,the shaft key on crankshaft holds timing of flywheel & ign,if shaft key Z bent or sheared & flywheel moves on crank this will change ign timing,2-3 degrees in either direction(retarded or advanced)and eng may not/won't run due to plug fireing either too early/late.This is why I said to check flywheel key in another reply.
 
Forgot to add,flywheel key is made of soft aluminum not steel,due to sheer age,vibration,causeing eng to stop suddenly by overloading blower,something caught in auger/impeller or a loose flywheel nut all of the above take their toll on key over the yrs.
 
Joe,


I hope you don"t mind responding to my questions...

I am going to pull the flywheel and am going to post some pictures.

Again, thanks for all your help.

D.
 

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