Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

my simplicity pro was running great last week, and now won't start. i cannot pull the starter rope unless i remove the spark plug. i took apart the carb bowl, removed the float and needle and sprayed with carb cleaner, re-assembled, no better. i squirted some gas in the cylinder, replaced the plug, no difference. it has electric start, i have popped the GFCI several times at the outlet. not sure what to do next!

I would stop trying to use the electric start until after you find out what is locking the engine. All that will do is break something. My guess is oil or gas in the cylinder causing a hydro lock? Could be the valves need adjusting and the compression release isn't working as well. I have heard of flywheel magnets coming loose and wedging, but that doesn't explain pulls fine with no plug. Also, someone suggested checking the oil level on another forum. Apparently if the oil gets too full it will hydro lock the piston on the down stroke.

Shryp, if it were oil causing an issue on the downstroke, I'd expect the oil might try to blow out of the crankcase breather as the piston went down and you pressurized the crankcase? Just wondering.

But I would, for instance, sniff the dipstick and/or the oil fill tube, to see if you smell gas. It's possible that gas is leaking into the crankcase (from something like a stuck float/needle valve in the carb), filling the crankcase. Is the oil level correct? If it has more "oil" (possibly also gas) than it did last time, you likely had gas leaking into the crankcase.

If you remove the plug, and pull the cord fast a few times, does anything spray out of the sparkplug hole? Like Shryp said, if you have a cylinder filled with gas/oil, you would be unable to pull the cord with the plug installed. But you might see some come out if you spin the engine over quickly with the plug out.

argh... i took the valve cover off and there was a piece of rod about 6 inches long hanging out of one of the holes. i pulled it out, it wasn't connected to anything. what the heck is it and what's next, take the head off? thanks for the help so far!

If you're under the valve cover, and there's a long straight rod, that sounds like it could be a pushrod.

I haven't worked on a Briggs OHV snowblower engine, just a Briggs OHV tractor engine. But on that, and my Tecumseh OHV snowblower engine, the pushrods were trapped under the rocker arms, and shouldn't just be moving around freely.

I'm trying to think of a reason why it wouldn't turn over without the plug removed, but also had a pushrod loose. Is the rod straight and undamaged?

If the pushrod in question is the one for the valve that provides the compression release (maybe exhaust?), I guess that could make sense. You'd have no compression release at all, so you'd be trying to push the piston up into a fully-sealed chamber, which would be much harder. I don't know *how* hard, though, whether it would be so bad that you couldn't turn it over with the pull-starter.

Do the rocker arms (the pivots between the pushrods and the valves) look OK?

Sounds like pictures might help.

please note that i COULD pull it over with the plug out. it's back together now but here's a couple pics i took today

sorry the pics are so huge

Yea, that is a pushrod. It is suppose to be straight. You will probably need a new one and make sure the rockers didn't get damaged as well. Sound like maybe you were over due for a valve adjustment and it got loose enough for the push rod to come out from under the valve. The other thing could have been the valve was hanging up some how and you forced the engine to turn over and that bent it.

should i attempt to repair? i read online that in most cases like this the cylinder wall will be scored and ruined as well. i can buy a replacement engine for around 450, but not sure i want another briggs like this. this is 3 years old; first time i've ever had a problem with any small motor. I have to say, this simplicity pro has been nothing but trouble since day one.

Did the things you read say why the cylinder would be scored? If you "just" had a pushrod come loose for some reason (say the rocker arm locknut came loose), I wouldn't have expected that to score the cylinder. But maybe there is some root cause that would explain cylinder damage.

But I'm no expert. I'm honestly just asking.

Maybe straighten the rod and put it back together. See if it will run. If all seems good get a new rod and put it back together. What size engine is it? You can get a 7HP replacement at Harbor Freight for under $100.