Briggs 28Q700 - Flywheel issues....

[Dr_Jim]

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.

 

[Lawnranger]

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.

 

[Dr_Jim]

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?

 

[chance123]

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?

 

[Dr_Jim]

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......

 

[Lawnranger]

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......

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.

 

[Dr_Jim]

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?

 

[Lawnranger]

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?

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.

 

[Dr_Jim]

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!

 

[Lawnranger]

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!

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.