I have a push mower with a briggs 3.5HP engine on it. Been working fine until yesterday. During mowing a very loud rattle started coming from the engine. I don't know much about how the clutch is supposed to work on these, but I noticed that the screen on the top of the engine stopped spinning. Isn't this part normally spinning around as the mower is running? I turned it off and started it again, and the screen was spinning around fast for about 10 seconds, then stopped and was barely spinning, and spinning erratically. Thanks for any advice.

Starter clutch got loose?

I have no idea. I don't know jack about them, but I can follow a manual if I can figure out what the problem might be.

Kind of hard to give you a diagnosis if you don't understand what we are talking about. But from your description oscarguy1 may be on the right track.

yes that screen should be spinning

Kind of hard to give you a diagnosis if you don't understand what we are talking about. But from your description oscarguy1 may be on the right track.

yes that screen should be spinning

Yeah, I'll have to take everything apart and see if I see something obvious. It's just a cheap 21" murray so it probably wouldn't be worth taking to somebody, but I'd rather not buy a new one if I don't have to either.

got a model number? More than likely your starter clutch went bad and the bearings are dried up. They are usually around $12 for the part

I couldn't find a model number last time I checked, I just read around though and I'll look for it to be stamped near the muffler. Is it a simple part to drop in? I've replaced the starter cord before so I can deal with that part.

The Model, Type and code should be stamped in the engine shroud just above the spark plug. Have a good one. Geo

Got the numbers mdoel: 95902 type: 3107, and pulled the starter clutch out. I shake it and I can hear the bearings rattling all over the place in there. I'll get a replacement. Part number looks like 399671.

the ball bearings should rattle around in their when they dont rattle is when you need to worry. Now what kind of shap is the debris screen ontop of the starter clutch in ? Did you try turning the engine over by hand with the spark plug out to see if you could reproduce the rattle? Have you checked the blade to see if its hitting anything under the mower ?

Alright, I'll have to look at it further. I'll put it back together to see if something might have just been lose, and I'll check the blades.

Just an update in case anybody else finds this thread and has a similar problem. I put everything back together and it ran fine, I determined the starter clutch must have just rattled loose. Well 1.75 mowings later it rattled out again. Now I can see that the threads have worn smooth on the bottom 1/2" of the clutch. I can see metal shavings all over the bolt that comes out of the top of the engine, but the threads on the bolt look fine. They must have used a softer steel on the clutch threads to make sure if there was a problem they wore out instead of the threads on the bolt coming out of the engine.

That "bolt" coming out of the top of your engine is part of the crankshaft. The Starter clutches are fairly cheap an easy to replace. So you will need to replace it if the threads in it are worn. Also make sure their is a washer between the starter clutch and the flywheel, it should be sorta domed. Make sure the dom is pointed up and tighten the clutch down good. To do this first tighten it down hand tight, then get large plunt tip punch with more then enough flat surface area on the buisness end of it. Place the punch on one of the larger taps of the clutch and use a hammer to tap the punch making it tighter. ( This is if you dont have a clutch removale tool. )

That "bolt" coming out of the top of your engine is part of the crankshaft. The Starter clutches are fairly cheap an easy to replace. So you will need to replace it if the threads in it are worn. Also make sure their is a washer between the starter clutch and the flywheel, it should be sorta domed. Make sure the dom is pointed up and tighten the clutch down good. To do this first tighten it down hand tight, then get large plunt tip punch with more then enough flat surface area on the buisness end of it. Place the punch on one of the larger taps of the clutch and use a hammer to tap the punch making it tighter. ( This is if you dont have a clutch removale tool. )

Thanks for the tips, I'm going to get the part today. And tighten it down good.