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Hello,

New to the forum and looking for some advice on getting it to start. I was cutting the lawn and the lower just turned off....not like it was out of fuel, but like the kill switch was hit. After it had cooled off I took the recoil cord off to access the coil, replaced it with a brand new one, along with the plug, still does not start, so I tried it with the kill switch disconnected from the magneto, still no go. Upon checking the oil, it was quite low, barely on the stick. Hmm oil pressure switch? I filled it to capacity and still no go. Tried starting fluid in the carb throat and directly into the cylinder....no start, seems to have compression as it pulls differently with the plug in vs. out.

Magneto was installed with a business card as a standoff from the flywheel, which has just been hit with 150 grit sand paper to be sure it was clean.

What next?

Thanks for the advice and direction in advance,

Broken Deere

There is a certain distance needed between coil and flywheel maybe business card was not correct distance? also follow all the wiring and see if there is a short anywhere?

Yes, I did remove the ground to the coil, and tried to start it both ways, connected, and disconnected....the spark plug wire is part on the coil, so its brand new.

I just measured the business card and its .014" (Fourteen Thousandth's of an inch) not sure what the spec is.

In answer to your first post: Based on what you wrote, you have not physically checked if you have spark. Start by checking to see if you have spark and try a new spark plug. It sounds like you lost spark but you never know for sure until you test the system. You could also have a defective new coil - it happens - but again, you do not know until you test.

In answer to post# 3, please post engine model, type, code, spec and/or serial numbers so someone who has access to engine specifications can look it up for you. You can also try a google search once you have your engine numbers.

Briggs and Stratton 121602-0281-E1

Will check for spark tonight.....However I doubt the brand new Magneto is bad, but it is something to look at.....

I will post the result.

Thanks

OHV SINGLE CYLINDER Armature Air Gap 120000 Horizontal Shaft .25.35 120000 Vertical Shaft .15.35

So you may have Incorrect armature air gap. but as above check to see if you have a spark.

The proper way to check for spark is with the plug in the engine with a spark tester. less then 5 dollars from most any auto parts store. Also could you of hit something and knocked the flywheel out of time?

Here is the spark at .014" gap

I dont know about the timing, however one bolt was missing from the blade, and it was a bit loose, but no the blade did not crash into anything.

So how does one go about checking the timing...?

thinkglad said:

Here is the spark at .014" gap

I dont know about the timing, however one bolt was missing from the blade, and it was a bit loose, but no the blade did not crash into anything.

Click to expand...

Fix the blade mounting problem before trying to start the engine.

thinkglad said:

So how does one go about checking the timing...?

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Remove the blower housing and related parts. You will probably have a large nut or bolt holding the flywheel on and you will most likely have to remove that retainer. Look straight down from the top of the crankshaft for a keyway. There is also a keyway on the flywheel. The two keyways should be lined up with a key. If you see one keyway in one position and the other keyway in another position, the timing is off due to a sheared key. The loose blade could be a result of hitting something and shearing the key in the process.

Report back with what you find.

Lawnranger said:

Fix the blade mounting problem before trying to start the engine.

Click to expand...

Done, that was the first thing repaired...... Also this mower has a blade clutch for lack of a better word, it can run with the blade disengaged.

Any idea on how I check the timing, I would think that the magnets on the flywheel just line up with the magneto when the piston in at TDC?

Lawnranger said:

Remove the blower housing and related parts. You will probably have a large nut or bolt holding the flywheel on and you will most likely have to remove that retainer. Look straight down from the top of the crankshaft for a keyway. There is also a keyway on the flywheel. The two keyways should be lined up with a key. If you see one keyway in one position and the other keyway in another position, the timing is off due to a sheared key. The loose blade could be a result of hitting something and shearing the key in the process.

Report back with what you find.

Click to expand...

Great,

I will inspect that crank key to see if it has sheered off.

Thanks again for the insight

From what I can see in the photo the key looks fine, so you may not need to remove it.

Yes I saw that as well, I took the photo down. So Timing ok, good spark. What next? Like I said this wont even ignite starting fluid, so its not a "fuel" problem. I guess I should check compression next?

Any ideas?

Well if you hav'nt done so, that is where I would go.

Ok so I was curious so I put my finger where the plug goes and rotated the engine by hand with the fly wheel. I can feel no compression, I can hear however air move in the carb throat when I cycle the engine...like a stuck open valve on the intake side?

Is this a possibility with this setup? I have never been into one of these...only V8's :smile:

Thanks.

Revision....small amount of air movement at the plug hole, not as much as what one would think.

Have you got a compression tester..? if you have good compression you will have air being pulled in the carb and pushed out of exhaust, when you turn over engine, if you don't have that you have a problem with valves or rings.

I dont have a compression tester, I can hear the engine "breathe" through the carb, but I dont hear it at the exhaust.

I will take another listen, I should hear it at the carb on the intake stroke only, and I think I hear it on every stroke of the piston.

I may put up a video of this.

Yes all strokes are herd through the carb, none at the exhaust and little at the plug hole. must be a stuck valve.

Ok any direction on getting into this? Is it worth it?

Remove the cylinder head and inspect.

OK, looks like I can get to it without pulling the motor, I will let you know how it looks and post some pics

At this point i would just sell it as is on craigslist and buy a new mower :/

Yeah.....I wonder if its hust the head ...anyone know of a source for a head?

No valve movement at all...Camshaft..? Im really not sure how the rotating assembly of one of these small gas engines are arranged? Do the valves operate right off the cam lobes? Is there a timing chain that could have broke?

Thanks

Now that I open this up it looks like this is not the engine I thought it was...????..... This is not an over head valve motor

This is a 12J802-1753 E1

Regardless the valves still dont move...

Open the valve cover and see if the exhaust valve is moving. and yes if you can upload a video.

Link to the video above, as you can see no valve movement.....:frown:

thinkglad said:

Link to the video above, as you can see no valve movement.....:frown:

Click to expand...

If you have some mechanical aptitude, which it seems you do, why not disassemble the engine and find out if you have a broken camshaft or stripped cam gears (many times they are plastic) and maybe you can get just a cam and gasket set to save the engine but only you know if it is worth the time. The mower could have a lot of hours on it so if it does, consider a new mower.

OK Im getting close to removing the pan, but cant seem to get the "transmission" off of the crankshaft. There is a setscrew that is super tight and thats about it, its soaking in penetrant right now.

Set screw out.....is a puller required to remove the trans off the crank?

Lawnranger said:

If you have some mechanical aptitude, which it seems you do, why not disassemble the engine and find out if you have a broken camshaft or stripped cam gears (many times they are plastic) and maybe you can get just a cam and gasket set to save the engine but only you know if it is worth the time. The mower could have a lot of hours on it so if it does, consider a new mower.

Click to expand...

Yes,

As you can see I'm going in, I have nothing to loose at this point, and a camshaft is only about $45.00
Plus some gaskets, way cheaper than a new mower of any quality. I know the history of this mower as it used to be my fathers. It was a weekend warrior and that's all I know.

Dads gone now, but his mower is still here! That alone gives me reason to get it running, and detailed seeing as its all broken down.

Any insight on what to do and any tips or tricks are greatly appreciated.

Broken Deere

Look around on the web and see if you can find a shop service manual with specifications. Before you disassemble the engine you may want to measure crankshaft end play. The thickness of the oil pan gasket usually is what is used to change crankshaft end play so make sure to get a gasket set as many times the set comes with several different thickness oil pan gaskets for adjusting crank end play.

As far as insight, tips & tricks go: Take your time, have a clean workbench, have rags handy, take pictures as you go, take notes as you go, study the parts as you take them off/apart, take note of bolt length as some bolts in the oil pan could be longer than others, keep parts in order of dis-assembly so you can put them back together in order, don't use too much force, use common sense, think things through before acting, if you get frustrated take a break, ask lots of questions on this forum if you get stuck and have some fun while repairing Dad's mower.

Good luck and let us know how it goes.

Thanks,

Everything mentioned above accounted for. I'm going to fashion an engine stand out of some plywood as well.

Do you know if the transmission is pressed onto the crank?

This is the parts list

Thanks for the parts list...now if I locate the service manual I will be set, looks like its not available on the Briggs website....

thinkglad said:

Thanks,

Everything mentioned above accounted for. I'm going to fashion an engine stand out of some plywood as well.

Do you know if the transmission is pressed onto the crank?

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The transmission is likely not pressed on but corroded on. Many times the crankshaft pulley or in your case transmission is corroded on due to the fact that wet grass is cut and gets stuck on the bottom of the deck which creates a humid environment until the moisture evaporates away. This moisture is what will contribute to rusting a deck from the bottom side and causing crank pulleys (and transmissions) to get stuck on the crankshaft. I would avoid using heat and go buy some top quality penetrating oil such as PB Blaster, Kroil or In-Force and soak that sucker for days or even a week or more until you can remove it with as little force as possible. Spray the crank on both sides of the transmission morning, noon and night until you free the transmission from the crank.

Good luck.

Done.

Will report back once I can get the case opened up!

This blade clutch is really not wanting to come off of the crankshaft at all... $#%^*&^$%!

Time fo a cold one .......

thinkglad said:

This blade clutch is really not wanting to come off of the crankshaft at all... $#%^*&^$%!

Time fo a cold one .......

Click to expand...

Hence the last sentence in my previous post. Been there, done that, got the t-shirt, sold it at a garage sale.

So it should actually just slip off of the crank and is only helu on place with the one allem set screw?? I cant find a manual or haw to on line......

thinkglad said:

So it should actually just slip off of the crank and is only helu on place with the one allem set screw??

Click to expand...

Many times that is the case. At the factory they come down the assembly line and someone slips on the clutch and tightens a set screw. Good to go.

On riding lawnmowers the rear wheels have a tendency to rust to the axles and are very difficult to remove so are the crankshaft pulleys. I removed mine and applied a film of grease so when the need arises I can perform maintenance with a whole lot less problems. A friend of mine got a good laugh when I told him what I did to prevent problems until he went to change his drive belt and his engine pulley would not come off. Guess who is laughing now?

Still soaking.......

thinkglad said:

Still soaking.......

Click to expand...

And soaking.....and soaking. Sounds like you need some "Energizer" penetrating oil.

You may want to try making your own penetrating oil by mixing 50/50 transmission oil and acetone in small amounts and dripping it on the shaft. I have not had the occasion to use this formula yet but I've heard it works wonders on rusted parts such as what you are dealing with.

Got it!!!

Cam gear is toast. Time to order up some parts........:smile:

Well done you find it....:thumbsup: keep posting what you do, lovely photo's.

check your valve's/rod's (looking at that photo) make sure there move up and down easy.

Valves and tappets seem to work good. I just need to look into how the oil slinger goes back on as it fell off when I opened the case.....

Oh yeah and order the camshaft!!

Not sure if this will help, it should do you can see it fit's under the gear.

This maybe better for you................

I didn't see you mention what it took to get the clutch off. What did you finally do to remove the clutch???

It just took some time to get it off...surprisingly the crank has little rust on it if any. I still have not ordered the camshaft as of yet however.

EngineMan said:

This maybe better for you................

Click to expand...

I'm wondering about the inner-play between the oil slinger and the "rod" that comes down from the top of the case, It seems to be connected to the carb linkage, however I have no idea of its pourpose and how or if it interacts with the slinger

thinkglad said:

I'm wondering about the inner-play between the oil slinger and the "rod" that comes down from the top of the case, It seems to be connected to the carb linkage, however I have no idea of its pourpose and how or if it interacts with the slinger

Click to expand...

That is part of the governor. Look at the oil pan and see where it attaches. You will need to line it up when you go back together.

I see the stops that the slinger rest on, the governor must line up in front of that, but I dont see specific spot for it. The good news I guess is that there is not too much movement in the governor so It shoult just fall into place one would think.