# Briggs and Stratton noises



## Disgruntled Sheep (Mar 26, 2012)

Hi I'm new here and have basically a 0 knowledge of small engines, but am trying to learn as I go...

I received 2 lawnmowers for free (both 4 stroke) as one had a working engine (they said) but a useless and destroyed body, the other had a broken engine, but nothing wrong with the body. I removed both engines and placed the working one on the body that could hold itself together, I used the blades of the working engine. After assembling it all, adding some new fuel (I have no idea how old the murky other stuff had been in there) I was able to start it. 

2 problems:

1) A noise that sounds as though the blades are hitting something when they spin. There is no obstruction that I can see, they don't hit the ground, nor the sides of the mower. I can spin the blades by hand and there is a raspy sound from the engine itself. 

2) The engine won't turn off even though the throttle is completely off (both on the handle and at the engine itself). I have been told how to short it, but shouldn't I be able to find a permanent fix?

Please in response, know that I am very very new at this so talk to me as if I know nothing (as that is close to the truth).


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## Rentahusband (Aug 25, 2008)

The raspy sound may be from the blade brake, if equipped. A pad that makes contact with the flywheel when a lever is released on the handle. Check to make sure this is functioning properly. Do you have a model # of the engine??


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## geogrubb (Jul 28, 2006)

The knocking sound is probably a loose blade, although they may feel ok it can still be loose if not properly installed or the wrong blade is installed. As rentahusband stated the raspy sound is the blade brake which also controls the shutoff, you need to get ignition and safety stuff compatable between the two mowers. Have a good one. Geo


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## Disgruntled Sheep (Mar 26, 2012)

Thanks both of you, I will have a look as soon as I have a free moment and post the results 

Also I will get the model number to help


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## Disgruntled Sheep (Mar 26, 2012)

It is a Briggs and Stratton "sprint 375"

On the engine is:
Model Type code
98902 0363 01 95081051

Does it matter that I used the blades from the working engine instead of the broken engine (as that engine came from the good body)?

I am trying to research up the blade brake system, so far have come across this guide but now I need to also learn about cotter and clevis pins :\ 

Also 



 does a pretty good job of explaining how to get at the flywheel, just not sure how it all relates together at the moment.

Any tips for a newb?


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## Rentahusband (Aug 25, 2008)

Hold up. A clutch brake and a blade brake are two totally different devices!! Which one are you talking about?
In a clutch brake system the engine will run but the blade will not spin unless the clutch is engaged, (like a manual transmission on a vehicle). 
In a blade brake system the blade spins with the engine at all times and when the lever is released a strap makes contact with the flywheel and acts as a brake, stopping the engine. There is also a grounding wire accociated with this system, that kills the spark. As far as the blades, if the blade is not bent, out of balance and the right length it should be fine. You may have a loose piece of tin under the deck that only acts up when the mower is running. Check to be sure there is nothing loose. 
Do you have the same mower as in the video?


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## Disgruntled Sheep (Mar 26, 2012)

Thanks for the help,

so far I've managed to stop the noise, it was infact an uneven blade. All is good with that. I now have a running (smoking) engine. I'm going to the shop to get some oil and will change it (as it is under the lowest oil level on the dipstick and murky black!!). It bothers me that it smokes as everywhere I read says that smoke is caused by "too much" oil when this mower clearly has too little 

*I'm still very new at this ..obviously  so could you please describe in better detail what I will need to do to make the mower stop? Also I have never heard of a blade brake or a clutch brake before reading it here, so ignore the links in my previous post. What will I need to do to fix the raspy sound?*

I have found a manual finder on briggs n strat page here:
Manual finder.. however following Murphy's law, the computer is also acting up and I can only access about 40% of websites. Gonna have to format and reinstall windows too I think  so I can't actually put in my model number and find the manual.

This manual However is almost 100% my mower. A few differences like I don't have a self propelled system and I have 4 cutter blades not 2. But it is basically the same engine by all accounts

Thanks so much for the help so far. I feel good just having an engine running that sounds like an actual lawn mower!!


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## Rentahusband (Aug 25, 2008)

So, the engine does run? Is the raspy sound only when you spin the blade by hand? On the opposite end of the spark plug there is a black cover that I believe says "system 2". Under this cover is the brake system/stop switch. When the lever on the handle is released, it engages a brake and grounds the ignition. Check to make sure this brake system is working and nothing is stuck or broke.


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## Disgruntled Sheep (Mar 26, 2012)

Yep running "fine" now  

I have only heard the raspy sound when spinning the blades by hand, but the engine noise would be more than enough to drown it out now. The other horrible noise it used to make was the uneven (due to being a touch loose) blades. 

Thanks for the info on the brake system. I will check for all of that. I am also planning on giving the lawn a good mow and hopefully after one long run I should see the last of the white smoke..:freak:

BTW, oil change was very very good. That old stuff in there could be used to waterproof a viking ship! Also cleaned and oiled the air filter for good measure.


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## Rentahusband (Aug 25, 2008)

You hear the "raspy" sound when spinning the blade by hand because the lever for the brake is up and the brake is engaged. *Disconnect the spark plug wire* from the spark plug, tie the brake lever to the handle and i'll bet you will not hear the "raspy" noise when you spin the blade by hand.


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## Disgruntled Sheep (Mar 26, 2012)

*Getting there....*

Thanks for that 

I have decided now to move into the world of photos (sorry for giant size, I don't know how to resize in this type of html. Just to make sure I am on the right track...

I couldn't find the part your are talking about, unless you mean to disassemble that area right behind the spark plug. I didn't do this as I am not sure if I will spill oil everywhere or not. I was watching another video (included) that is very similar to my engine. Main differences that I noticed:

- No wire going around flywheel to the back
- No padded braking system

But it looks very similar to the red circled are on my photo. I have included close up photos too. When you move the throttle, there is a connection that is made/broken. Is this related to the kill switch at all? Is this the area you are talking about, or do I have to take the rest of the mower apart? Just watching the vid again... Is my mower missing the kill switch all together?

BTW spark plug is filthy black, but the engine runs...


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## Disgruntled Sheep (Mar 26, 2012)

*Got it*

:thumbsup::thumbsup:Never mind, I GOT IT!!!!! :thumbsup::thumbsup:

I removed the air filter for a better look and then I could see properly. There was a small bit of metal (I'm sure it has a name) that was attached to the black wire (mine is at the front, I knew I was on the right track :dude that needed to poke through a hole. It's in the red circle of the picture, but it's covered up. Probably why I couldn't tell from the pic! I bent it up by hand and now my mower stops on command. Granted that command is leaning over the front of my mower and pushing the throttle with my finger, but a command none the less!!

Just a quick question, what is the role of that big white plastic thing that moves in and away from the flywheel?

Thanks so so much for the help. I have learnt heaps. Now to get the whipper snipper going...


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## Rentahusband (Aug 25, 2008)

If you are reffering to the "white thing" in the video, it is called an air vane. It regulates the throttle depending on the speed of the motor. The more throttle, the more tention is applied to the vane via a spring. The flywheel generates air that applies force to the vane. The spring is needed to control the rpms to keep the motor from over reving and blowing up. No photos on my end, just the you tube video.


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## Disgruntled Sheep (Mar 26, 2012)

Not sure why the photos aren't coming up, they are fine on my end  Here are the embed links if you are interested

http://i.imgur.com/6ocBP.jpg 
http://i.imgur.com/ghzyw.jpg
http://i.imgur.com/Q1QnF.jpg
http://i.imgur.com/yFvJv.jpg


Thanks for that info, that's exactly what I was talking about. Makes perfect sense thank you


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