Quote:

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Originally Posted by KeepItSimpleStupid

http://www.datasheetcatalog.org/data...uji/1N5407.pdf

There is a digit missing. It's probably, or should be, a 1N5404.

Note hat there is a white band on one side. This side goes away from the coil.

It probably should not swivel. it may have been crimped, but that isn't a good way to make a connection to a solid piece of wire.

Are you able to test with a multimeter?

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Thank you. You are right the number is 1N5406 and the white band is away from the coil. I can get it tested. What should it read? How do you measure it?

OK, so I'm off on the breakdown voltage. 4 vs 6.

A lot of the multimeters have a diode test mode. In this mode, it passes a small amount of current and reads in voltage. Since it's a silicon diode, it should read around 0.6V and infinite when the leads are reversed.

If your capable of measuring a DC voltage, then a 1k resstor in series with a 9V battery connected to the diode and measure the voltage across the diode in both directions. Again, around 0.6V in one direction and open in the other.

The low ohms mode x1 will be a go/no go test. The diodes usually fail shorted, so if it reads nearly zero in both directions, it's bad.

A 9V battery in series with a 1K resistor in series with an LED connected to the diode will light in one direction and not the other. Again, this is a Go/No Go test.

The resistor, LED, battery clip and 9V battery are available at Radio Shack. 1/4 W or bigger for the resistor should be OK.

Quote:

---

Originally Posted by KeepItSimpleStupid

http://www.datasheetcatalog.org/data...uji/1N5407.pdf

There is a digit missing. It's probably, or should be, a 1N5404.

Note hat there is a white band on one side. This side goes away from the coil.

It probably should not swivel. it may have been crimped, but that isn't a good way to make a connection to a solid piece of wire.

Are you able to test with a multimeter?

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Well this mower is still not running and I am going to start tours through the jungle since my yard is getting very high... help? I changed the diode and it still does the same thing, it will sputter with the starter as if it is on the verge of running but will not catch and run. It looks possible the timing is off but the key looks fine. How do I verify that the motor is timed with a cylinder at top when the flywheel is on the magneedle? Help I have noticed the one spark plug is new but it is starting to look like it is producing combustion but the other is clean like new.

You know. I think we may have been led astray.

Did you by chance do a valve adjustment on the engine?

I'm not sure of the clearances, but it's normally done with the piston at 1/4" down on the power stroke. Intake and exhaust on that cylinder are done at the same time.

Quote:

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Originally Posted by KeepItSimpleStupid

You know. I think we may have been led astray.

Did you by chance do a valve adjustment on the engine?

I'm not sure of the clearances, but it's normally done with the piston at 1/4" down on the power stroke. Intake and exhaust on that cylinder are done at the same time.

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No, there has been no valve adjustment. The reason I wonder about the timing is because the "passenger" side piston is down about a half inch when the timing mark on the flywheel is lined up with the left side of the magneedle. I thought the piston should be top of cylinder at that point.

This is definitely something out of the ordinary and is going to require someone really good at looking at the facts to determine which variable is not correct.

The plugs will likely fire at the same time, just one in the power stroke and the other in the exhaust stroke.

That was the premise of 1 coil for 2 cylinders in automotive engines.

Quote:

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Originally Posted by KeepItSimpleStupid

The plugs will likely fire at the same time, just one in the power stroke and the other in the exhaust stroke.

That was the premise of 1 coil for 2 cylinders in automotive engines.

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So have you ever heard of such a thing as having a 16 hp Briggs that has
1. spark (brand new quick start plugs)
2. fuel (fresh)
3. Compression seems to be good
4. Cranks over good and fast
5. combustion smoke comes out of exhaust

But with all of this it will not run?

If those plugs have the "booster gap" they don't seem to work for standard ignitions.

Get a normal plug.

Sometimes the easiest answer is the right one. Try draining the fuel tank and put in fresh fuel

Hi guys. I have a similar Craftsman with the same model no as being discussed. The one I have runs just fine with the passenger side plug disconnected but won't run at all with the driver side disconnected and PS connected. It acts like it has the power of 1/2 an engine. I cannot find an engine number. But the real question is, does the flywheel have to be removed to find the diode(s)? Thanks for this thread, it surely will help.
Regards to all.

This could still have a weak coil. A little trick to test that is take a good spark plug and cut off the curl part so its now a straight out piece away from the center of the plug. Crank engine, If the spark won't make that bigger jump then it's a weak coil for that cylinder. A spark doesn't mean its 'Hot" enough to run the engine..

Do you have the actual No# of the engine yet.
Model
Make
Type??

Of the engine itself..

I didn't look back on the previous pages but did you check the flywheel "key" If that is off then the timing will be off.

How to check on basic valve adjustments...

http://www.youtube.com/watch?v=j77Y5...C8D2D&index=40

http://www.youtube.com/watch?v=hGkn0...C8D2D&index=41

Is there fresh fuel?

Do you have the actual No# of the engine yet.
Model
Make
Type?

Of the engine itself..

I didn't look back on the previous pages but did you check the flywheel "key" If that is off then the timing will be off.

******
No I have looked everywhere. All the shrouds are off and I have not seen or felt a number nor have I found a stamped plate.

I have not pulled the flywheel as I am trying to avoid that, but will if req'd

Thanks for the spark plug 'tip'.

Regards to all.

earlgo:

Briggs stamps the numbers on the blower housing and then PAINTS over them. There is no plate.

You will either have to feel for some small depressions or look very closely with a flashlight. Usually it's on the flat portion.

Hi Guys:
In this case the numbers are stamped on the driver's side heat shield on the flange facing front. I took all the shields off and put them aside so I could fix things. This one is a Model 402707 type 0157 02 code 86060512 and someone already said that, so stupid me.

I got both plugs to fire and the engine runs with either plug wire disconnected. However someone put automobile plugs in it: Champion 12Rs. The good news is the radio hardly has any static in it.

I adjusted the needle valve and it starts and idles OK but has NO power. It barely turns the blades and moves in 3rd gear on grass that has been cut 3 or 4 times. When the throttle is opened up all the way it dies. I am thinking plugged fuel filter or junk in the float chamber.

My old but newer 12.5 HP has a lot more power than this alleged 16 HP model.

Regards to all.

Hi guys:
New plugs, the right ones this time, new gas filter, draining the schmutz out of the float bowl, a careful carb adjustment according to the manual, and I am in bidness, as they say.

Thanks for your support and have a great holiday weekend.

One down, one still to go.

Good job!

earlgo If you don't have the manual for your engine I have it for you down the raod.
And the parts to cross reference with

http://www.briggsandstratton.com/mai...OMESTIC_LO.pdf

http://www.briggsandstratton.com/mai...=MS6931_LO.pdf

At least you have more insight on how its all laid out

Getting the engine manual and parts list was easy once I had the number from the heat shields.
What I would like is a copy of the lawnmower manual 917.255821 but even the guy on e-bay with a bazillion manuals doesn't have this one.

If I can get all the heat shields back in place and the lights fixed, I should be set to go.

I can take photos of anything someone needs to see, in reference to this mower, that is. I am assuming that one can link to photos in an on-line photo website.

Regards to all.

You can post pictures using "Go Advanced/Manage Attachments"