Export thread

Briggs 28Q700 - Flywheel issues....
Apologies for not having the exact type #.....however my problems are 'general'.
Older snapper lawn tractor 155LTH 42BBV (15.5hp B&S horizontal engine),.....solenoid and starter died. Diagnosed with meter.
Replaced starter and solenoid. Now passes proper current..etc.

Ring gear (plastic) had a LOT of teeth missing so I am attempting to replace it with the new aluminum gear.

Issues:

1 - Cannot get flywheel off. Used puller, broke bolts,...used puller some more. Used knock tool hitting it with hammer with prybar underneath..etc. Currently I am spraying it daily with PB Blaster and hoping for some magic to happen.

2 - And this is where my memory is sketchy. I feel like I was previously able to rotate the flywheel by hand endlessly,...meaning 360deg....720deg....it would continue to rotate.
NOW...it seems to rotate only about 350 +/- degrees before it 'hits' something. I can feel/hear compression...etc. The plug is still in,....but this definately is like a 'clunk' when it reaches its rotational limit.....I can rotate back and forth no problem....but simply not endlessly.
I am not sure if this is normal. Something tells me this is bad. Dropped a magnet maybe?

I have not 'beaten' on the flywheel or crank with a 10lb hammer at all....in fact I have been very careful not to use the 'hammer' approach much at all and haven't hit the flywheel itself with anything other than a rubber mallet (and not that hard either).

Any insight? Advice? Thoughts?

Thanks!

Possibly the pry bar underneath hit the stator and/or magnet. You will find out once you get the flywheel off. I've had some really tight flywheels and had to resort to hitting the puller while under great tension to get them free. You may want to buy some grade 8 bolts for your puller and try again. Make sure to clean the taper on the crank and flywheel with brake cleaner or similar to remove the penetrating oil before you reassemble everything.

Let us know how it goes.

Thx.
I will try that as I am getting a littler desperate with it.....grass is growing!
Grade 8 bolts are a good call too!

I hope it's a magnet only! I could use some JB weld on it and put it back......but something is definately jamming up in there............

There is a Briggs tool that slips over the smooth end of the crank made for this purpose. Just as you did with the pry bar under the edge of the FY, with this tool in place, you must hit it "very" hard to shock it free. The real reason for the pry bar is to lift the crankshaft's end play just enough so when you strike the end of the crank, the crank will have somewhere to go. Otherwise, if you didn't, when striking the crank, you would also be striking the FW side of the crankcase. I am sure you know this, but "DON'T strike the end of the crankshaft without that tool, otherwise that smooth machined shaft will get mushroomed.

Interesting,....although the way you describe it sounds off,...the crank shaft is recessed in the flywheel,....and the flywheel bolt screws down into the threads in the crankshaft.

So I have a piece of pipe that fits into the flywheel and rests on top of the crankshaft,...this allows force to go to the shaft and not the flywheel,...and protects the threads of the shaft as well.

Not sure about the tool you describe,....im looking online,....not sure how it could go 'over' the shaft....

A "VERY" hard hit is not something I have done yet,...only used 'tapping' with a standard hammer and some hard blows with rubber mallet. I could certainly get the 3lb BFH and WHACK it! (the shaft with protective insert...NOT flywheel)

Dr_Jim said:

Interesting,....although the way you describe it sounds off,...the crank shaft is recessed in the flywheel,....and the flywheel bolt screws down into the threads in the crankshaft.

So I have a piece of pipe that fits into the flywheel and rests on top of the crankshaft,...this allows force to go to the shaft and not the flywheel,...and protects the threads of the shaft as well.

Not sure about the tool you describe,....im looking online,....not sure how it could go 'over' the shaft....

A "VERY" hard hit is not something I have done yet,...only used 'tapping' with a standard hammer and some hard blows with rubber mallet. I could certainly get the 3lb BFH and WHACK it! (the shaft with protective insert...NOT flywheel)

Click to expand...

OK I see that you do not have a recoil clutch. I would take a short spare bolt with matching threads and screw it "all" the way into the crankshaft. Pry up on ONE edge of the FW and hit the head of that bolt VERY HARD. It WILL break free from the taper.

Hmm....I must be dense today.....I dont think im explaining it right.

The flywheel "hole" has no threads,....the crankshaft has threads,...and the top of it is recesssed in the hole on the FW,...the "bolt" goes into the crank nad the top of it overlaps the flywheel....thereby holding the FW on (although the FW sure the f&^% isnt going anywhere anyway).

Are you suggesting getting a bolt with the same threads,...that has a smaller diameter head and screwing it into the CRANK.....so that I can then get a whack onto it? There is no way to screw a bolt into the "flywheel" unless you mean into 1 of the 2 5/16th holes that are on each side of the center of the flywheel (where the puller goes).

Is the bottom line that I need to get a SERIOUS whack onto the crank without damaging the threads? While prying one end of the FW? I "think" my piece of pipe would allow for that just fine?

Thx again man.....

Dr_Jim said:

Hmm....I must be dense today.....I dont think im explaining it right.

The flywheel "hole" has no threads,....the crankshaft has threads,...and the top of it is recesssed in the hole on the FW,...the "bolt" goes into the crank nad the top of it overlaps the flywheel....thereby holding the FW on (although the FW sure the f&^% isnt going anywhere anyway).

Are you suggesting getting a bolt with the same threads,...that has a smaller diameter head and screwing it into the CRANK.....so that I can then get a whack onto it? There is no way to screw a bolt into the "flywheel" unless you mean into 1 of the 2 5/16th holes that are on each side of the center of the flywheel (where the puller goes).

Is the bottom line that I need to get a SERIOUS whack onto the crank without damaging the threads? While prying one end of the FW? I "think" my piece of pipe would allow for that just fine?

Thx again man.....

Click to expand...

What I am saying is to get a spare bolt with the same threads and if you have to, put some washers under the head of the bolt to get the head "above" the top of the flywheel. Tighten that bolt a little so you won't stretch the threads when hitting it. You want this bolt tight so the full force of hitting it gets transmitted to the crank (and not the threads if loose) hit it HARD while prying the FW

Thanks Chance.............I will pick one up on the way home and try this tonight!
Appreciate it.

When you put the washers in to keep the head above the FW, MAKE SURE THE OD OF THE WASHERS FITS INTO THE RESESS OF THE FW AND SEATS DIRECTLY ON THE CRANKSHAFT.
I stated to use a spare bolt because you are going to mangle the head when you hit it.

THANKS! Chance!

So....taking your advice,...and 1 whack! And it popped right off.
There were no thrown magnets,....I cleaned it up....put on the new ring gear...put it back on....and....no joy.
Here is what it is doing:

1 - Starter motor 'tries' to start it,....but only briefly...it spins up, engages the ring gear and rotates the engine maybe 1-1.5 turns before stopping,...essentially acting like it only has enough 'oomph' to turn it a little bit. note:* I kept starter motor gear that came with starter...I did not replace with starter motor gear that came with ring gear. They have same #of teeth,...I will say though that they are slightly different in 'tooth shape'.....not sure if that could be source of issue? Doubt it.
- With meter, the wire to starter is supplying 12.5v when attempting to start. So solenoid is good.
- Battery has fresh charge and shows 12.5v as well......after awhile of trying to start it...battery was at 11.9v

2 - After the initial attempts (maybe 4-5times) of trying to start it,...eventually the starter would engage the ring gear but wouldnt turn the flywheel at all.......

3 - When the flywheel would turn, in the initial attempts to start....the engine made NO sound like it was trying to combust or start.
- New plug
- New fuel filter


So...I guess now I need to start going down the long list of diagnosing the whole spark,fuel,compression thing. A lot to learn,....will be spending a good bit of time on google today!
I know good info exists on testing spark,....carbs...etc..etc.

One thing I read about was trying to start the mower without the plug in and see if it rotates the flywheel. I am not sure what doing this proves,......thoughts?

Any other, overall thoughts? Tips or tricks?
FYI - The mower came with the house, and was definitely not maintained well. It ran fine for a few months,....then this all sorta happened at once. Wouldnt start....solenoid/starter motor followed quickly.

I would check valve lash adjustment before doing anything else. If the valves are out of adjustment the starter will have a difficult time trying to crank the engine past the compression stroke. If you don't know how to check the valves make sure you ask because the procedure is very specific.

ha! I was finding reference to that in other threads online as well!

You suggest asking if I don't know how to check the valves?: I do NOT know how to check the valves! At all! So any links or reference or info would be VERY helpful!
Something about this tells me I am pulling the engine and disassembling?

I also still feel that I should check for spark, and make sure the plug is wet,.....and all that stuff as well? Just so I can 'confirm' various system function?

By cranking the engine with the spk plg removed will circulate oil throughout the engine and possably loosen it up a little. With the spk plg in while cranking, have you tried a shot of carb spray in the carb to initiate combustion?

Thx...I will definitely try that!.....Still wondering about the lack of spin on the flywheel....even if it's not going to combust the starter motor should spin the flywheel more than 1 turn......

Dr_Jim said:

Thx...I will definitely try that!.....Still wondering about the lack of spin on the flywheel....even if it's not going to combust the starter motor should spin the flywheel more than 1 turn......

Click to expand...

Check valve adjustment first. Go to youtube and watch videos on how to adjust Briggs & Stratton OHV valve adjustment. Get familiar with the process first then ask specific questions and finally attempt the repair.

yup..done that. Quite a few....seems simple enough:
-remove cover
- crank to TDC
- Use feeler gauge to check valve (5-7 thousandths is proper)
- adjust as necessary.....
- replace cover. (little smear of perm black rtv.....)

What should I expect from the gasket?....Is that potentially toast? Or is it different than an auto gasket and is reusable?

Dr_Jim said:

yup..done that. Quite a few....seems simple enough:
-remove cover
- crank to TDC
- Use feeler gauge to check valve (5-7 thousandths is proper)
- adjust as necessary.....
- replace cover. (little smear of perm black rtv.....)

What should I expect from the gasket?....Is that potentially toast? Or is it different than an auto gasket and is reusable?

Click to expand...

On some Briggs engines you have to rotate the crank past TDC to compensate for the automatic compression release so be sure to look up for your particular engine. Also, some intake valve clearance specs are .004, exhaust .006, so once again make sure to look up your particular engine. Many times the gasket is unharmed and can be reused, just wipe it off and the mating surface.

You advice has paid off!. It was the valve clearence. Fired right up afterward!! :thumbsup::thumbsup::thumbsup::thumbsup:

Now....when first running (it has always done this for the 3 months weve had it)......for about 3-5 minutes the exhaust emits dark smoke.
Any thoughts here? Is there some sort of fuel additive cleaner or such that will hellp clean stuff out?
Carb cleaner?

I guess I want to continue working on this mower and bring it back up to as a good as shape as possible! Fluids and proper lubing I got sorted. But for 'helping out' the engine?.....Any advice appreciated!

Dr_Jim said:

You advice has paid off!. It was the valve clearence. Fired right up afterward!! :thumbsup::thumbsup::thumbsup::thumbsup:

Now....when first running (it has always done this for the 3 months weve had it)......for about 3-5 minutes the exhaust emits dark smoke.
Any thoughts here? Is there some sort of fuel additive cleaner or such that will hellp clean stuff out?
Carb cleaner?

I guess I want to continue working on this mower and bring it back up to as a good as shape as possible! Fluids and proper lubing I got sorted. But for 'helping out' the engine?.....Any advice appreciated!

Click to expand...

I've seen improper valve adjustment cause the problem you have/had too many times to count and it is a no-cost check/repair.

As far as the dark smoke goes, what color is "dark" to you? Color matters when it comes to exhaust smoke and I can't advise you until I know the color. Do keep an eye on engine oil level and condition. You engine could have some wear on the valve guides which would allow some oil to leak back into the combustion chamber when the engine is off where it would smoke for a few minutes until its burned off but that is just a guess at this point.

One of the best known fuel system cleaners available is polyeither amine and this can be found in products such as BG 44K and Chevron Techron. You can find Techron in just about any auto parts store. I treat my fuel container according to the instructions on the bottle so every time I fill my lawnmower the fuel is already treated and if I have any fuel approaching the 30 day mark it goes in my truck fuel tank. You can try treating a five gallon fuel container and use it in your mower over several tanks of fuel to clean the system up.

Thanks!
I would have to say that dark is "black". Just not super dense...so its not like a THICK, DENSE black smoke....but the color is black.

Black smoke means the air/fuel ratio is too rich. Causes could be a dirty air filter, improper mixture setting on the carburetor (if applicable as some carburetors are not adjustable), choke plate not fully opening, excessive carbon in combustion chamber causing incomplete combustion, etc. Perform the simple checks first and report back with what you find.

Re: Briggs 28Q700 - Flywheel issues.... NO JOY!

Well! I should not have spoke too soon after only running the mower a few minutes last night. (After valve job).

Things are NOT well.

Tonight:
-Put in new air filter....put shrouds back on....

Fired it up. The starter had trouble cranking,...it engaged....and spun....but very hesitantly....Upon re-tries it started. But had to crank awhile!!

*Note: When starting you must have the brake depressed.

When it would 'catch' and start running....it ran rough....10-30seconds...when I took my foot off the brake it died.,....and backfired a big spark Started realizing it would die everytime after I let off the brake.

On more start attempts I noticed that keeping the key in the "start" position while waiting for the engine to catch....with the starter running: The + wire on the bat was smoking and melting the rubber sleeve around the + terminal

Finally I decided to start it, keep my foot on the brake (since for SOME reason taking my foot off the brake causes the engine to stop)....so I ran it like that for awhile (maybe 1 minute)...before I noticed an orange glow "pulsing", "emitting" from the muffler.
SO I shut it down immediately. The muffler area was HOT....TOO HOT.

So I am at a loss.
- Something is up with the safety switch on the foot brake. I put in a new solenoid. There were 2 fin clips....blue wire and white wire. I did not think it mattered which wire went to which fin....maybe it does?

- Could I have screwed up the valve adjusment?

- Again, the starter motor has trouble turning the flywheel....it DOES,...but only have several start attempts.

- Pulled plug....nothing crazy...looked fine.

- Brand new hi amp cold crank battery. New starter motor. New ring gear. New solenoid. New ignition switch. New fuel filter. New air filter. New plug. Checked and gapped properly.

Thoughts?

Your mower has multiple problems and we will take one at a time. First you will need to remove the negative battery cable and then the positive, in that order. The fact that the positive battery cable is smoking and melting the insulation tells me that there is too much resistance and most likely the cable end where the eye is crimped has corrosion or is not tight. In regard to electricity, resistance = heat and you will need to correct the high resistance in the connection. You will probably need to purchase new cable ends, cut the old ones off, strip an inch or so of insulation and crimp new eye connectors on. Make sure you battery posts are clean and the connections are tight when you go back together with the connections.

Second, you will need to address why the muffler is glowing orange. Again, you are dealing with too much heat. You should go back and recheck the valve adjustment. What procedure, exactly, did you use to adjust the valves? How much valve clearance do you have? As I mentioned in an earlier post the process is very specific and must be performed correctly. Since you are the eyes and fingers in this situation you will have to post everything you have done and how you did it.

Third, the starter control circuit has several safety switches in the system so you will need to test each switch individually to find the one that is not working properly. For now, you can set the parking brake to hold the clutch/brake pedal down when you want to start the engine but do not try starting the engine until you get the other problems sorted out.

Report back with your findings.

WOW! there are several unrelated issues here. The muffler glowing red has nothing to do with electrical, BUT if your flywheel key is semi sheared, your ign timeing will be off. For example, if the engine is fireing when the exhaust valve is still a little open, "that" combustion will exit out the muffler. I have seen this same thing with burned ex valves where they don't seat well. With the spk plg out,, does the engine turn over freely and loose? It should.