Troubleshooting a Briggs Quantum

[hanyoukimura]

Hey guys, although I have an ongoing thread I figure I'll give this its own so as it'll get noticed.

Today I acquired a Poulan Pro 96146001 self propelled mower with a Briggs Quantum.

The guy I got it from told me he was running it one day when it spit oil out then died.

He tried to start it there but it wouldn't fire. Had good compression though.

So I take it home and have a look. First of all its out of gas. So I put some gas in it and change teh blackened spark plug.

After a couple pulls it fires up and seems to run well. There's some black puffs at first then it cleared up.

It seemed to be making a lot of vibration noise despite the fact that the mower was running smoothly. So I tipped it over (muffler facing down of course) and come to find out

A few minutes later as it was running it suddenly idled down, then began to sputter to the point where it almost died. As it was sputtering it puffed out black smoke. I shut it off and then started it back up again. Started right up but idled slow and then started sputtering. After that I pulled the new spark plug out which was black. I cleaned it off, put it back in and started it up. No difference.

I left it for a few minutes check the grill (BBQ chicken!). When I came back I started it up again and for about 30 seconds it ran fine, but then it once again it started to sputter

Not sure about this one. Any thoughts?

 

[ILENGINE]

Black smoke means that it is running rich. For some reason you are getting a extra shot of fuel. could be intermittent float sticking open or a dirty carb, dirty air filter, Air vent in carb clogged. so the short of it sounds like a good carb cleaning may help alot.

 

[hanyoukimura]

Today I decided to work on it. I figured the carburetor would be the issue, and it was, in a way. It turns out that someone attempted to "service" the carburetor...or something. I took the small bolt that holds the air filter assembly and the whole carburetor came off. Turns out the 2 bolts which hold the carburetor to the engine weren't there! Further inspection showed it was also missing the o-ring that goes between the carburetor and the engine.

The carburetor itself was pristine, although I cleaned it anyway.

The other problem I discovered is 3 of the 4 mounts for the shroud were broken, so the shroud was really only attached with 1 bolt.

I had a spare shroud but the recoil was broken. I hate replacing the recoil springs/assemblies because it never seems to go well. Instead I opted to pop out the rivets and swap recoil assemblies. Man I hate rivets. Got it done though.

Back together, it fired right up doesn't puff black smoke out now! At first it doesn't idle smooth, but it smooths out as it warms up. However, it seems to not idle as smooth as some of the other Briggs engines I have. What else should I look into to smooth it out?

I did give it a quick wash, cleaned up pretty well.

 

[Xenas Garage]

Just acquired the same mower. It's cosmetically in nice shape but
the rivets are all broken on the starter recoil and the carb needs
a good cleaning. Gonna try some low profile nuts/bolts to secure
the recoil assembly as I don't own a rivet gun.