# Simplicity riding mower questions



## desertsteel (Oct 16, 2013)

Howdy all! I originally posted this in the Simplicity section and got no replies. Thought I'd give it a shot here. I have never needed to own a riding mower before. I lived in the desert for the last 17 years and kept the grass that needed cut (if any) to push mower size to save on water.

I recently bought a Simplicity 5216H, 16hp B&S I/C twin with a 36" deck and a snow-blower as my main yard tractor. Now that i have used it for a couple of months and have gotten used to it's personality, I could really use some knowledge and insights please...

The first thing I'd like to deal with is the starter, it sounds like it is dragging or rubbing when I start it up. Is this starter rebuildable, could this just be debris and it needs a through cleaning? Or is it on its way out?

2nd, is the pto and drive belt pulleys supposed to make racket when your foot comes off of the pedal? Nothing appears to be loose, it has a belt that is in good shape, it just sounds overly loud to me. Everything seems to run very smoothly! I have visually looked at all of the pulleys. None appear to be bent or wobbly, they look shiny and the belt is in good shape.

3rd, it's now backfiring every time i shut it off, nice flame blows out of the exhaust. I pulled the solenoid off of the carb to clean it and i thought there was supposed to be a plunger of sorts, but there is nothing and I'm not seeing any adjustment screws on the carb. So i pull the choke out before i shut her down and she just puffs a bit.

4th, it won't idle down anymore. when the throttle is pushed all of the way down it sounds like the motor is still about half throttle rpm's. I have verified the throttle cable is traveling as it should to the carb and everything is free and moving.

The only issue this mower had when i bought it was the starter issue. i've been using it twice a week since i bought it so i haven't wanted to tear into it yet . I should have a bit of a break to work on it between leaves and snow...i hope.

I've wrenched enough over the years that I can figure out most things but it would be nice to able to pick other brains for a change and have an idea of what I'm looking for before I get into tear down mode.

Thank you in advance for sharing your knowledge.


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## Country Boy (Mar 18, 2010)

The starter could be dirty inside, but I'd also check the gear. They like to use a plastic gear, and sometimes they get chewed up and can make a racket. You can pull the starter apart, but the brushes can be a real PITA to get back in. Just be careful pulling the lower cap off so the springs don't go flying, never to be seen again.

There will be some sound when you release the clutch pedal, but I'd check the idler pulleys. It almost sounds like the pulley bearings might be getting dry, making a racket when they spin. See if you can get them away from the belt so they spin freely, and then spin them as fast as you can with your hand. If you hear a grinding or howling noise, then the bearings are getting bad. I've seen pulleys that are shiny like new with bad bearings before.

If there is a solenoid on the carburetor (shiny metal cylinder with one or two wires coming off it), then there should be a plunger coming out of it that would stick up into the carb when screwed on. Sounds like someone may have cut it off due to the solenoid not working. When you turn the key to the run position, the solenoid should click and the plunger should retract. If that isn't happening, then the solenoid is bad. Its called an "afterfire solenoid" because it snaps shut when you turn the key off to prevent any more fuel from being mixed with the air when the engine is shutting down. If that isn't working, a fuel/air mix will enter the cylinder, not be burned, and then be pushed into the hot muffler where it explodes. That's the flame you see coming out of the muffler. I'd get it fixed, because I've seen mufflers get blown apart from the backfire. They aren't cheap.

Most four cycle small engines idle around 1400-1800 RPM, and top out between 3000 and 3600 RPM. So, technically, the do idle at half RPM. If yours isn't dropping in speed when you push the lever to idle, then make sure the cable hasn't moved in the clamp that holds it to the engine frame. There should be a clamp at the end of the cable that holds the outer sheath still while the cable moves. If that clamp loosened up, then the sheath can move and the cable will be out of adjustment. Also check the stop screw on the carburetor. There is a small screw at the top of the carb where the throttle shaft rests against at idle. If that screw got moved, then the throttle plate can't close at idle, and it will run too quickly.


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