Tecumseh 4HP won't start ! Have spark !

SO ... got a NEW working compression checker from Amazon ... part II ! Hooked it up to mower, put screwdriver thru carb, because there is no throttle . Got 88 LBS of compression ! Put plug back in, pumped primer 3 times , tugged away at pull start, just like before ... NOTHING! So there's another stupid question , when I checked for spark I put plug in the end of the wire put it close to body of mower , I used my Dewalt to spin motor at the fan. Got good robust spark ! Could it still be the plug ? Anyhow.... I don't know what's going on!
 
Coil tricks

1.Remove small black kill wire from coil. This bypasses key switches and safeties FOR TESTING ONLY. If the coil is good, should run the fuel tank dry. Note you will have to ground the plug wire out to kill the engine. Not a big deal for testing only.
2.Remove coil. Polish coil mounting pads ON the coil and the pads where the coil sits. Or make sure a ground wire is connected IF yours has a ground wire. Clean off all the corrosion and rust. Coils need a good ground to create spark.
3.Test coil with an open gap type tester at the plug wire end.
4.Recommend running non-resistor plugs for better spark.
5.Coil air gap normally is 0.008" to 0.010". Check YOUR engine manual for proper specs. Piece of junk mail between the coil is fine using the flywheel magnets to pull the coil against the junk mail and flywheel.

Sometimes the coil will start working again. Remember to reconnect the black kill wire to shut her down AT the key.
 
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MowerTedII said:
Put plug back in, pumped primer 3 times , tugged away at pull start, just like before ... NOTHING!
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Do you SEE fuel jumping up into the carb venturi out of the brass emulsion tube? You have to look INTO the bore of the carb. When you hit the primer a little fuel fountain so to say will jump up with every pump.



 
MowerTedII said:
when I checked for spark I put plug in the end of the wire put it close to body of mower , I used my Dewalt to spin motor at the fan. Got good robust spark ! Could it still be the plug ?
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If you have spark at the spark plug boot end and are grounding to CLEAN UNPAINTED metal on the block, spark is good.

If you connect the suspect plug as above and no spark, plug is dead. So plug attached to the boot end grounded on clean metal. Should see a blue spark AT the plug gap. Might have to turn the lights down or off to see it. Can see it better in low light.
 
sgkent said:
I have had bad spark plugs. Get a new one from your local auto parts store like AutoZone, Napa, O'Reillys etc., and not online.
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For sure. Do NOT shop on amazon nor ebay. Pirated plugs are all over town. NGK's are the worst.

While shopping get a non resistor plug. These mower colls are not real good on healthy fat sparks. Champion makes non resistor plugs. My fav NGK, most all are resistor plugs. Can't buy non resistors in NGK.
 
Tecumseh RUNS ! Before I was going to do any more Diag. I thought I'de go back to simple . Found my can of real starter fluid , put screw driver down carb ( NO THROTTLE ON THIS ) shot some down the throat. Gave it a couple of tugs ! Started right up !
Don't really know if I didn't anything to make it start other than the squirt of fluid, but it starts !
Thanks to everyone who tried to help !
 
I'd still change the plug. Real starting fluid is ether, which takes considerably less energy to ignite than a gasoline mixture. Real starting fluid can crack a head, blow out head gaskets or worse. That is why early on I suggested using Berryman's B-12. It works well but has significantly less risk of a failed head gasket.
 
MowerTedII said:
Tecumseh RUNS ! Before I was going to do any more Diag. I thought I'de go back to simple . Found my can of real starter fluid , put screw driver down carb ( NO THROTTLE ON THIS ) shot some down the throat. Gave it a couple of tugs ! Started right up !
Don't really know if I didn't anything to make it start other than the squirt of fluid, but it starts !
Thanks to everyone who tried to help !
Click to expand...
All of this would be your step #1 to try. Should of been done on page 1 post number 1. Fuel related issues are the highest faults in mower engines.

If the engine fires off for a second or two with a flammable juice sprayed into the carb as you did, tells you 4 things.

1.She wants more fuel - lacking fuel delivery, find out where and why.
2.Getting plenty of air.
3.You have SPARK and at the CORRECT TIME.
4.You have enough COMPRESSION to run.
 
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