B&S 11.5 Intek Won't Start

EddieC

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I have an 11-year old Snapper riding mower with an 11.5 HP B&S Intek engine (NOT electric start) that (all of a sudden) won't start:

1. In the past, engine typically starts on the very first pull and runs great
2. Cut the grass a week ago just fine and shut off normally by cutting the gas flow to the carb
3. Went to cut the grass a couple of days ago and NOTHING....would not start
4. A couple of times (out of many) when I pulled the cord, it froze and would not pull....thought it was going to break my wrist!


Here's what I've tried so far (not necessarily in order):
a. Drained the tank and put in fresh gas...also replaced the fuel filter
b. Pulled the carburetor off and cleaned out thoroughly (I put a new one on 6 months ago)
c. Replaced the spark plug
d. Replaced the magneto armature
e. Pulled the flywheel and checked the flywheel key.... looked OK, but replaced just in case
f. Removed valve cover and reset the valve clearance
f. Sprayed starter fluid into the air intake... would not even think about firing

Any other options that I might try? I'm out of ideas
 

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dougand3

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Is plug wet or dry after no start? Could be flooding, so starting fluid makes it worse. I'd try starting fluid when you know plug and combustion chamber are dry. Check for spark. An inline tester is better as you see spark under compression. Compression is the other thing after all you've done.
 

EddieC

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Checked the plug after trying to start and it's dry and the spark looks good. In my original post I talked about how when I'm pulling to try and start.... every so often it will just lock up and not pull at all. Then the next pull is normal. What does this indicate?
 

Tinkerer200

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I would disconnect the "Kill" wire from the engine and try. The interlock mod. often failed on these after several years. As for pulling/not pulling, sounds like the recoil is fouling up sometimes, perhaps recoil spring not tight enough OR could be the Compression Release is hanging up, bad spring.

Walt Conner
 

EddieC

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With getting a good spark in the plug, I am assuming that the kill switch is not a problem. I also re-adjusted the valves again and checked to make sure that the push rods were not bent or damaged....all looking good. Nothing more than I know to do here. All suggestions welcome!
 

dougand3

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Back to the basics:

1. Proper fuel/air mix in the combustion chamber.
2. Adequate compression.
3. Good spark at the proper time.

If above 3 happen - it has to run.

So, is compression good enough? Sometimes, a tester is of limited use if engine has valve tick decompression. You might not pull rope fast enough to get past it.
 
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