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!

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.

mtbmike wrote:
Well ur making progress :)... Its VERY unlikely that there's any cylinder damage... if it was me I would order a new push rod and install it 90% chance that will fix it.. u need to know how to adjust valves correctly or u will have future issues.. most likely reason why the push rod got bent was it became to loose while running.. there alot of u tube videos on how to adjust valves if ur not sure..

just wanted to add my thoughts on these briggs motors as u mentioned having issue from day 1... I work on these motors alot and will say there are a very reliable motor as long as there maintained... for example if u never had this engine tuned up or the valve clearances checked within the 3 years you've owned it then that's an a problem.. most consumers buy snowblower or lawnmower and don't realize they need yearly mainetance... I would NOT give up on this motor especially for a bent push rod its a simple low cost fix...

From the picture I can see that rod is bent, period. So now I will assume the valve was tight and that's why it bent over time. Lastly, it is so bent that the valve stayed closed causing so much pressure in the cylinder that the motor couldn't turn over and that is why the GFCI circuit tripped as the starter amperage increased trying to overcome the piston pressure.