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Hi,

I have a 14.5HP Briggs engine and was able to get it running right, very smooth. As of today when
turning the key their is a loud banging noise and then it runs fine. So now every time
you start the engine their is a loud clanging noise and it goes way after the engine
runs for maybe a second or two. If it is the engine and not some issue with the mower deck,
what could cause this initial noise that then goes a way fairly quick?

Thanks,

Jim

Sounds like the starter...more specifically the bendix key.

Make sure the engine mounting bolts are tight to the frame. The will back out about 1/16 of a turn and allow the engine to move on the frame and will clunk loudly most times at start up and shut down.

ILENGINE said:

Make sure the engine mounting bolts are tight to the frame. The will back out about 1/16 of a turn and allow the engine to move on the frame and will clunk loudly most times at start up and shut down.

Click to expand...

i agree

Thanks to all who have replied. I did not mention that the problem seems to have started
after I disabled the kill switch under the seat. The reason for doing this was because the
engine would just cut-out for no reason. Now the engine runs fine. I will keep the above
in mind and check these things out. It might also be the deck/blades. But the main thing
is I am hoping the issue is not a connecting rod or some other internal engine part. And the
replies thus far indicate, 'no not an internal engine part' - a good thing.

Thanks again,

Jim

JimP2014 said:

..... It might also be the deck/blades.....

Click to expand...

I might be reading to much into this part but are you starting the mower with the PTO turned on? If so that might be another reason for the clunk you hear.

Wildcat said:

I might be reading to much into this part but are you starting the mower with the PTO turned on? If so that might be another reason for the clunk you hear.

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I was thinking the same thing

I am not trying to start with PTO engaged. It is a weird setup where the height and the PTO are the same
lever. Pulling up all the way is how you disengage the PTO. It might be this.

Jim

JimP2014 said:

I am not trying to start with PTO engaged. It is a weird setup where the height and the PTO are the same lever. Pulling up all the way is how you disengage the PTO. It might be this. Jim

Click to expand...

Take the deck belt off and see if there is any change.

"Take the deck belt off and see if there is any change. "

Good plan. I will post back with the results.

Jim

JimP2014 said:

I am not trying to start with PTO engaged. It is a weird setup where the height and the PTO are the same
lever. Pulling up all the way is how you disengage the PTO. It might be this.

Jim

Click to expand...

Is this on a Troy Bilt? My PTO and deck height is on the same side as well.

Wildcat,

I have an older MTD. The lever for the deck height is the same exact lever for the blades.

It works like this. Raise the mower deck up all the way and the blades are supposed to dis-engage.

As you drop the lever so the deck gets closer to the ground, the blades engage. Normally, as I am
sure you know the deck height and PTO lever are separate levers. Not this MTD, it is all-in-one combo
idiocy.

Jim

JimP2014 said:

Wildcat,

I have an older MTD. The lever for the deck height is the same exact lever for the blades.

It works like this. Raise the mower deck up all the way and the blades are supposed to dis-engage.

As you drop the lever so the deck gets closer to the ground, the blades engage. Normally, as I am
sure you know the deck height and PTO lever are separate levers. Not this MTD, it is all-in-one combo
idiocy.

Jim

Click to expand...

That just stupid. I guess you can drop the deck or take the belt off to the deck and see if you still get the clunk noise. I still think its a starter problem personally.

I just checked, it was quite simple when the engine starts the whole engine moves. So it was a missing engine bolt.

ILENGINE said:

Make sure the engine mounting bolts are tight to the frame. The will back out about 1/16 of a turn and allow the engine to move on the frame and will clunk loudly most times at start up and shut down.

Click to expand...

That was it - thanks!

It does jump around when mounting bolts work loose. Glad you found the problem.

Guys, I had this issue. Found this thread and it helped. Turned out I was missing one motor mount bolt. I had it in my garage because at some point after losing it, I found it in the yard. I just did not realize what it went to.

Anyway, before finding this thread, I could tap on the starter with a rubber mallet and then my mower would start. Then it made the loud noise and would stop. Tap on the starter with the rubber mallet before I could get it to start again. Then a loud noise and it would stop. After screwing the motor mount bolt in, the mower won't start. Even after tapping the starter with the rubber mallet. It just spins.

Any ideas guys? I need to get my mower going. My lawn is looking like the amazon jungle.

I'd guess your starter pinion/bendix gear is chewed up. They are usually nylon or plastic. Post your engine model # - on a valve cover or shroud.

The engine model # is 28V707

Search web for Briggs 28V707
Parts houses come up. eg: https://www.ereplacementparts.com/b...-engine-parts-c-16758_17347_17430_217077.html
We see that engine has 2 types of pinion gears.
First, tho....need to see which you have...may pull a starter cover or blower housing

This is my starter. Looks like metal. Not worn out, to me, anyway. I do not understand why it would start before I put the motor mount bolt in it but not after.

Try starting while looking at how pinion interacts with ring / FW gear.

I watched. The gear goes up. Not exactly what to look for other than that.

Getting info is like pulling teeth here. So, the pinion gear goes up...it meshes with the ring gear? it turns the FW and engine spins? Pinion just grunts and FW doesn't move?
If the starter spins the engine at a fast clip....the no run issue is elsewhere....fuel, compression, timing, etc.

I vote on loose engine mount bolts.
Just watch the engine with the hood up when you start it.

Lol, I just responded to a 6 year old question!!

To the new guy: Did you change the battery? If so, you may have it hooked up backwards.

Here is a video. Hopefully it helps to understand what is going on.

The battery is hooked up correctly.

Link to video:

Take off the top cover and look at things. I hear a noise like a loose coil or something rubbing.

We need to clarify terminology a bit. Starting vs. cranking, etc..
When you turn the key all of the way to the right, we should call "cranking".
So is your engine trouble cranking, and not starting? Or not cranking/spinning at all?
Start over from the start. When you tighten the bolt, will it crank?

The flywheel looks to be spinning fine.....fuel/air delivery, compression, spark at the correct time....1 of those is faulty. Simple tests:
1. Pull spark plug. Re-insert in boot. Ground metal plug on cylinder fin. Turn key and look for spark.
2. Squirt gas into plug hole. Re-install plug and boot. Turn key and see if engine RUNS for 2-3 secs.

There is spark.

I dipped the end of the spark plug in gas and put the plug back in...did not run.

I doubt that is enough fuel. Spray 2 secs of WD-40 or such in plug hole and try.

Wildcat said:

That just stupid. I guess you can drop the deck or take the belt off to the deck and see if you still get the clunk noise. I still think its a starter problem personally.

Click to expand...

the way this design works is there are large springs on the back of the deck so as you lower the deck it makes the springs pull the deck back tensioning the deck belt

its a variation of the concept used on single speed trannys using the variable pulley to tension the drive belt but in this case they shift the deck position to tension the deck belt

and i agree its not the best design

The noise sounds like it may be the screen on top of the flywheel is rubbing, perhaps.

Take the air filter off and pour a dribble of gas in.

LostInMO said:

Here is a video. Hopefully it helps to understand what is going on.

The battery is hooked up correctly.

Link to video:

Click to expand...

Was that video shot under water? Throw that potato camera away.

slomo

Far as it not starting with loose engine mount bolts, doesn't the engine block bolt to the frame and create the - ground path back to the battery? If that is so, no wonder it wasn't starting. In that case there was a poor ground. Or is there a ground strap on the engine block that later connects to the - post? I'd have to see that engine setup to find out.

slomo

dougand3 said:

I doubt that is enough fuel. Spray 2 secs of WD-40 or such in plug hole and try.

Click to expand...

Did that. Did not start.

? guess a crank pin/con rod with l o o s e tolerances would make a noise while cranking?

Fish said:

The noise sounds like it may be the screen on top of the flywheel is rubbing, perhaps.

Click to expand...

That is what was making that sound.

LostInMO said:

That is what was making that sound.

Click to expand...

Remove the spark plug and rotate the engine. Listen for unusual noises.

slomo

Fish said:

Take the air filter off and pour a dribble of gas in.

Click to expand...

Did that. Did not start.

slomo said:

Remove the spark plug and rotate the engine. Listen for unusual noises.

slomo

Click to expand...

Do not hear anything unusual. To me, anyway.

I tightened up a couple of more motor mount bolts. Still won't start.

I found a bolt in my yard. Is there a 5th motor mount bolt? 4 are in. Not sure where this one goes if that even is what it is. Before I tightened the other motor mount bolts, the engine did shift. Now, it does not.

LostInMO said:

I tightened up a couple of more motor mount bolts. Still won't start.

I found a bolt in my yard. Is there a 5th motor mount bolt? 4 are in. Not sure where this one goes if that even is what it is. Before I tightened the other motor mount bolts, the engine did shift. Now, it does not.

Click to expand...

Sounds like a shifter bolt. ????

slomo

It won't fire too well on wd-40. Pour a dribble of gas in.

If the gas doesn't work, you need to check for spark and compression. Film yourself trying to rotate the flywheel backward so we can see how the compression looks. Then take out the plug and test for spark, if none, remove the little wire going to the coil/kill wire and test.

Put up a pic of that bolt too.

Fish said:

Put up a pic of that bolt too.

Click to expand...

It is the same size as the other bolt I had. I put the other one in the missing motor mount bolt hole. Not sure where this one goes yet.

Put up the number off the tag under/behind the seat, we can look at the parts diagram to see where those fasteners are.

Just for the info, did the motor have all 4 mount bolts in place? The smaller push mowers have 3, the bigger ones have 4.

Fish said:

Just for the info, did the motor have all 4 mount bolts in place? The smaller push mowers have 3, the bigger ones have 4.

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No. i could see 3 in place and saw 1 missing. I put one in that spot so now it has 4.

If you put up the model number of the tractor, we can look and see where the fasteners like them are.

Fish said:

If you put up the model number of the tractor, we can look and see where the fasteners like them are.

Click to expand...

Looks like a 40508x92D

Yeah, those Murrays had a lot of them self tapping ones.

Was the other one you put in the motor painted with Murray red?

This is one that holds the engine.

Fish said:

Was the other one you put in the motor painted with Murray red?

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No. Looks like the one in the pic.

Those are used in a lot of spots, you might take a look. I usually go back with a regular bolt and locknut, so they won't fall out again.

JimP2014 said:

"Take the deck belt off and see if there is any change. "

Good plan. I will post back with the results.

Jim

Click to expand...

Still waiting for that reply....

seattlepioneer said:

Still waiting for that reply....

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Yeah, 6 years is a long time to wait!!!

Well I had a friend who has a shop look at it. The connecting rod broke. He said a new engine, with labor and all, would cost $700. Mystery solved, I suppose.

Fish said:

Yeah, 6 years is a long time to wait!!!

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maybe he's got slow internet..

Scrubcadet10 said:

maybe he's got slow internet..

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Yeah, Hughesnet!!