If you pulled gears out and didn't line up the dots, then your timing is out. Probably you have the piston up against an open valve at this point.

Take spark plugs out, turn the engine clockwise by hand, see what happens.

Walt Conner

thanks for responding.. what am i looking for when i turn the engine.

***"what am i looking for when i turn the engine?"***
You are trying to determine if the piston is hitting one of the valves because you did not correctly align the timing marks of the crankshaft and camshaft gears.
By removing the spark plugs, you either eliminate, or confirm the possibility that the engine refuses to turn over due to gasoline (or oil) in cylinders.
If after you remove the spark plugs and HAND TURN the engine, and observe that the engine turns freely, look at the spark plug holes and notice if there has been any gasoline or oil expelled from the hole.
If the engine now turns over freely, and you see no fuel or oil coming out of the spark plug holes, your valves need to be adjusted (following the correct Briggs procedure.
If the engine now turns freely and you saw gasoline come out of the spark plug holes, it might be due to fuel running into the engine while you had the engine tipped on its side to repair the sump leak, or the gas may be due to a faulty carburetor.
BUT, if the engine still does not rotate freely with the spark plugs removed............you have mis-timed the crank and cam. Yes, the sump cover will have to be taken off again. You need to be extra careful the second time as your mood will be somewhat sour and you could be prone to making other fatal errors.
If you are lucky and you have not tried too many times to turn the engine over with the crank/cam timing off.......you might just need to retime the engine correctly. But if you have repeatedly attempted to crank the engine, you may have bent a valve already.
A good clue that a valve has been bent will be the obvious loss of compression on the affected cylinder.
Another way to detect a bent valve is to set the engine to the correct position for valve check/adjustment and measure the actual clearance between the rocker and the valve stem and compare that to the valve clearance specs in the manual. If you find the clearance of a valve to be much greater than specified, that valve is bent.
And I presume you have no idea of the Briggs procedure for valve adjustment nor the specs. The valve clearance specs for your engine are .004" to .006" (try to set at .005") for both intake & exhaust valves.

{{gwi:332750}}

{{gwi:332751}}

thank you so much. great info. will take care of it when i get home. thanks again.

o.k ... I can feel it, i'm almost there. Opened everything back up and fixed the timing. put it all back together, and it fired right up. idled fine for a bit, then started backfiring... could i have the valve adjustments off?

Enough gas in the tank? Carburetor clean?

yes and yes

"could i have the valve adjustments off?"

Yes, it usually takes me 2 - 3 tries to get things right. Do you have instructions or did I send you the B&S Service Bulletin on adjusting the valves? Address below, put in proper format and remind me of engine and what is wanted.

Walt Conner
wconner5 at verizon dot net

Follow Walt's lead on the valve adjustment. You have to understand that each cylinder must be set to its own correct position before adjusting the valves on that cylinder. You CANNOT set the valves on both cylinders at the same time, you must position the cylinder, and then set the valves for that cylinder only. Then you move the crank til the other cylinder is positioned correctly before setting the valves on that cylinder.

Yes Walt, you sent me the info already. Thanks to everyone on this forum. You guys are great. will let you know how it turns out.

o.k.. briggs and stratton model # 445777. now when i turn it over, it idles great. at medium throttle it purs like a kitten. but, when i throttle it up to cutting speed it backfires out of the exhaust on the side of the #1 cylinder. i have checked, double checked and rechecked all gaps (valves, spark plugs (new)). i did notice that the spark plug on the #2 clyinder was kind of black sooty looking. my lawn looks terrible and this lawn mower is about to be used for target practice. help!!!!

OK, this is probably as good a time as any for you to finally post the engine's 6 digit "Type number" so the exact IPL can be viewed online.
But my suspicions as to what you are having now, based on the fact that this is a "2-barrel carb with single main jet".
I suspect you have a vacuum leak in the intake duct work, possibly at the juncture of manifold to head, or at the base of "carb to manifold" on the affected cylinder.
You say that the opposite spark plug appears "sooty". That indicates a rich fuel mix is being burned in that cylinder.
Having a vacuum leak on the opposite cylinder might possibly cause the carburetor to allow the sooty cylinder to hog most of the fuel while the leak would also cause the backfiring cylinder to burn very lean.
How about posting the coloration you see on the plug from the backfiring cylinder (#1).

type number is 0168E1. spark plug on cylinder # 1 is spotless.

OK, communication breakdown.
I asked "How about posting the coloration you see on the plug from the backfiring cylinder (#1)."
Response was "spark plug on cylinder # 1 is spotless."
From the earlier description of the plug from cyl #2, "kind of black sooty looking", I inferred that the plug was, well....."black and sooty". And that is a very good descriptive phrase. However....."spotless" just does not do the same thing for me.
If I asked what color your car is, and you say "spotless"..... that still does not tell me the COLOR.
Color of plugs is like "a view to what's happening inside the combustion chamber".
Some possible colors are Black & dull (means it's burning too much fuel), Black and shiny (means it's burning oil), Brown and dull (means it is maybe just a little rich on fuel), Light brown to tan (means the mixture of air & fuel is near perfect, Grey to white and powdery (means it is burning extremely lean and hot).

Light brown to tan

Well, the good news is that cylinder # 1 seems to be burning a good mixture despite the backfiring.
Swap the spark plugs to opposite cylinders and see if you get the same results and coloration to the plugs. You will have to run it for at least 5 minutes before trying to read the plug color.

o.k. will try tomorrow a.m and let you know the results. thanks alot.

switched the spark plugs around this morning and ran engine for 10 minutes. same result, the plug in cylinder #2 came out black and sooty looking, and the plug from cylinder # 1 came out looking more brown to tan(i cleaned the soot off of it before i put it in).

Brodi, have you (or anyone else, that you know of) had the carburetor apart?
Do you have a service manual for the engine? E-mail me if you need/want one.

I have not had the carburetor apart. and yes i would appreciate the manual. what do you think i'm looking at? sorry it took me a while to respond, had to go out of town for a day.

OK, switching the spark plugs to opposite cylinders, and getting the same plug coloration on the same cylinders rules out the chance of a plug problem.
Blackened spark plugs typically indicate a fuel/air mix that is too heavy on the fuel side of the scales (rich mix). But there is a caveat in that logic: The engine must be in known good working order regarding everything else about the condition of the engine. And we do not know if everything else is actually good (at this time) so the process of elimination is necessary to cross off things that might be causing one cylinder to blacken its plugs while the other cylinder appears to be operating normally.

So, we know cylinder #2 blackens its plugs. Usually this means it is running too rich, but cylinder #1 does not blacken its plug. Both cylinders are fed from the same carburetor. Though it is a 2 barrel carb......the fuel metering is done with a single main jet, so theoretically.......both barrels should be receiving the same volume of fuel from the bowl, and feeding the same volume of fuel to their respective cylinder. Using this logic one would expect that both cylinders would either be running rich, or that both cylinders would be running a normal mixture. And because of this discrepancy, we must consider (and try to eliminate) the possibility that there is an intermittent sparking problem with one of the ignition coils, or that the engine has a mechanical fault that is causing cylinder #2 to either be running rich, or to be suffering from incomplete combustion.

At this time, I suggest you swap the ignition coils to opposite cylinders to see if the plug coloration follows the coil, or still remains with the cylinder.

As I stated before, if you want a PDF copy of the service manual, send me an e-mail. Your forum e-mail capability is not active (because you opted out) but mine is active.

will try it when i get home this eve. my email is jamesworful@yahoo.com

switched the ignition coils, and the problem stayed with the cylinder. got the manual, Thanks Alot!

Success at last!!!!!!!! Well, I guess I didn't check my valve clearences quite close enough. I rechecked my exhaust valve and it was closer to a .004. Put it to a .005 and perfect. Thank You so much to everyone here that helped me out. I could not have ever done this without you guys.