I forgot to add that when i put the carb cleaner or start spray into the intake, I have been getting a backfire. Carb open or closed, didnt seem to make a difference.

chk for flywheel key partially/fully sheared.. or valve adjustment.

First off Thank You

Would the engine crank if the flywheel key was partially or fully sheared?

Yes, it can still crank over with a sheared flywheel key, though it may not turn the crankshaft as faithfully as with an intact key.
Have you ever had the flywheel off of the engine?
If so, did you torque the flywheel nut to 100 ft lb when you reinstalled it?
If it were a "fuel problem", the carb cleaner sprayed into the carb throat would provoke a response of trying to run, though briefly.

I have never taken the flywheel off. I found it weird because i shut it down with no problems and no signs and now it wont start.

What would cause the backfire? Could the spark not be intense enough to fully ignite the fuel?

Coil airgap .010-.012

Coil just might have failed, though would be weird in the timing of events but have seen weirder stuff happen.

Bad fuel if you just fueled it up after stopping.

Sticking valve from using stale fuel.

RC12YC plugs are resistor type and will have a very fine arc, you will need some shade to see it well.

Just thinkin outloud..

It's rare, but I have seen the flywheel nut/bolt come loose from the factory and sheer the key.

How is the compression?

Following deerdoctor's suggestion of a sticking valve, remove the valve cover and inspect the rocker arms and pushrods.
If you find a pushrod not in its rocker arm (lying loose), that is a good indication that a valve (usually it's the intake valve) was stuck open and pushrod fell out as the camshaft rotated away when you began cranking.
If the pushrod is out of place, it might also have gotten bent when you began cranking (if a valve was stuck open).
And finally, if the pushrod is out of place AND IS BENT.... the valve might also have been bent in the process because it would have been struck a hammer blow by the piston when the pushrod was momentarily trapped on the edge of the rocker arm.
Even IF both valve rockers and pushrods appear to be in their correct places, you will need to rotate the engine crankshaft by hand (spark plug out and turn the grass screen on top of engine) and get the engine into the correct position to check the valve clearances.
Specs on your engine are INTAKE = .004", EXHAUST = .006".

I have a 26hp BS vtwin engine which appears to do the same thing. I was completely stumped. I'm no mechanic but, but I have a good understanding of how these engines work. I went through all the spark, Intake, Exhaust valve specs, fuel filter bad, gas, flywheel key etc...I then took apart the carb after removing from the engine, cleaned completely including using a compressor to be sure all areas were free of dirt. Reassembled and engine started instantly. appears gas was not getting to the spark plugs. actually plenty of gas poured from carb not the bowl upon removal. NOW, the problem is i have to do this regularly to keep the engine going. I can stop after using for two hours and go to use the tractor the next day and nothing. Is it possible that even though the air filter and prescreen are relatively new that dirt is getting into the carb from somewhere else????

Any dirt that somehow "bypasses" or gets through THE AIR FILTER, is not ging to find its way into the fuel portion of the carburetor, period!
I am not sure what you are saying > "actually plenty of gas poured from carb not the bowl upon removal."
The "bowl" of the carb is the removable part of the carb where the float is found.
You say you "went through all the spark, Intake, Exhaust valve specs, fuel filter bad, gas, flywheel key etc".
Did you replace the fuel filter with a new one?
I have seen some bad advice posted on this forum by some transients where it was suggested that the fuel filter be removed and an open piece of tubing be inserted into the hose ends as a test of fuel filter being clogged.......I hope you did not do that.
For the very reasons it is necessary to filter the fuel.....you should NEVER operate the engine (even for a moment) sans fuel filter.
When you "clean" the carb, do you find any foreign matter stuck in the jets or lying at the bottom of the fuel bowl?
You have not posted the engine model & type numbers nor told us what machine this engine is in, so some data is missing.

BS Intek V-twin 26Hp on a Husqvarna LGT2654. I purchased this tractor 3 years ago and it was Identical except for color to the comparable JD. Other than price of course. As far as the gas from carb, not the bowl. I had removed the bowl from the carb and there was no gas in it at all, there was some reddish colorization that cleaned out with a q-tip and lint free cloth. After I removed the small Brass plate from the top of the carb and turned the whole unit over, gas poured out of the openings exposed. I have not found any foreign matter in jets other than the reddish residue in the bowl. As far as checking all areas of the tractor. I replaced the fuel filter with a new one, checked for spark at each spark plug, had plenty of spark but no sign of gas. assumed a flywheel key broken, removed the flywheel, Key was fine, I replaced anyway because I had purchased one. cleaned all magnetic areas on flywheel and corresponding areas for each plug. All was good, and reset to factory settings for gaps. Removed the OHV covers to check, everything was clean, no damage. I checked the gap for both intake and exhaust and they seemed good. That is when I decided to take off the whole carb assembly from the engine. Went through everything, honestly thinking I didn't do anything to "Fix" it. I just cleaned it. I was very surprised when it started when I put it back together. And no, it never started after any of the other steps, not even a POP like it wanted to. I know its time to clean the carb again, when the tractor seems to want to back fire with no load at full throttle. I have done this three times now, and I fear I have to do it again. So thus I have no idea why this is happening. Could it be the intake valves are actually not set at proper gap?? I believe and I don't remember exactly that they were set at .005 when I checked.

FYI, the Model # of your ENGINE is 445877, there is also a TYPE # listed on the engine following the Model #. You will have to find the type # on the engine itself to find the Briggs IPL online (if you want to do that).
OK, you find the bowl is completely empty after the tractor has sat for a day or more.
There are only a couple of ways the bowl can empty completely under those conditions.
(1) The fuel shutoff (anti-afterfire) solenoid is leaking to the outside of carb. If this is what is going on, you should be able to detect a strong odor of gasoline in the area where your tractor is parked, and even be able to see a drop of gasoline drip from the solenoid or off off the solenoid wiring at a point away rom the solenoid if the gas is wicking along the wire.
(2) This engine is running hotter than it should be and the latent heat content in the engine, coupled with high ambient temps in your storage area, is "boiling the bowl dry" after you park the tractor.
I can think of no other ways a bowl can be full when the engine is stopped, and then be found empty a day or so later.
It is not plain and clear looking at the owner's manual online, but, does this tractor feature a fuel pump or is it gravity fed?
I infer it has a pump because if it was gravity fed, and a leak was present at the fuel solenoid, your chief complaint would not have been about starting and running, but instead you would either be reporting that you have a visible fuel leak, or that the tank is empty after tractor is parked a few days.

Type 0760 E1
Code 070118YG

There is a fuel pump, and plenty of fuel pumps through to carb. With this being said and cranking engine over then taking apart bowl, there is no fuel in it, however, when taking apart the area where the fuel goes into carb there is fuel there. Its just not getting to the Bowl The solenoid does not appear to leak, and I can here it engage and disengage when turning the key to on position. This all being said, I find it odd that it is an occasional problem that taking apart the carb and blowing out the jets clears up. Thats why initially I wondered if dirt was getting in somehow through the air filter. I'm just a novice and i am just confused. I even thought of buying another carb assembly. But I don't want to throw bad money at a problem that might not resolve it.

Well, with the small bowl this carb has, and a concentric ring float, plus the rather large size of the emulsion tube assembly................there is not a lot of room left over within the space of the bowl, so the actual volume of gas present is not much. And that very small volume of gas may very well be boiled off or evaporate after the engine is shut off, and that would explain the "empty bowl".
But by the same logic (little volume of space in this bowl), the bowl should refill almost instantly when the fuel pump begins pumping when you crank the engine.
So, it's possible that the float, or the needle valve are sticking in the UP position, and all you are really accomplishing by "cleaning" is to "knock loose" or free up the offending component.
Try this: Next time you try to start the engine without success, remove the float bowl (leave carb on engine).
Try to remove the bowl without disturbing the float. Very carefully touch the float and see if it is stuck in the UP position. If the float falls when you touch it or jostle it, the float or the needle valve was somehow stuck and the fuel from the pump could not enter the carb.
If you find the float is already in the DOWN position, check carefully to see that the needle valve itself is not stuck in the UP, or seated, position. You can check for that by lifting up on the float with a fingertip while you observe the needle.
Now, no matter what you found regarding the position of float and/or needle valve, perform the following test while the bowl is still removed.
For safety's sake, do this carefully. First, unplug the wiring connector to the fuel solenoid and lay the bowl and solenoid away from the tractor.
You will need a "helper" to sit in the seat and crank the engine because you are going to be up front doing something else.
Using a plastic container, (you know, like Cool Whip or margarine tub) hold the container under the carb to catch any gasoline. Tell your helper to crank the engine. You should see gasoline begin to run into the container as soon as the starter turns the engine. If you see gas running into the container, stop your helper from cranking.
Having seen fuel flow into the container, pour the fuel back into the tank and put the bowl back on the carb.
Connect the fuel solenoid back and try to start the engine.
If the engine starts now (remember, you did no cleaning this time), the problem is not in the jet, but in the float or the needle valve.
Post back after you have had the opportunity to do this test. This might take a day or so of sitting after a couple of hours of use (your description)for the problem to return.

Thank you everyone for your responses!!

Deeredoctor:

coil airgap is the gap between the magnet and the magneto/armature? If so I used the business card rule

I fueled up before I started it the first time and cut the whole front lawn with it.

Maybe a sticking valve, going to pull the valve cover? today and take a look

bayme:

i do not know how to check compression without a tool, any nifty tricks to kinda tell without actually buying the tool to check it?

mownie:

is that the trick where i pull the plug and use a screw driver and rotate the piston till its at TDC? where the screw driver is at its farther point outward?

A crude way to check compression is to remove the spark plug, and get the wire out of the way. Open the throttle and choke plate. Put your finger over the plug hole and turn the engine slowly by hand. You'll feel the vacuum or compression. Second best way is get the compression tester and have somebody crank the engine with the throttle and choke plates full open. Best way is a leak down test.

mcherchio,
I have developed my own fix for this problem. It is not B&S or JD approved but it sure has fixed many of the carb's I have encountered having symptoms you describe.

The very easy test it to just tap the carb bowl with a plastic or rubber handled screwdriver. Then try to restart the engine. If it starts then continue reading.

When you inspected and cleaned the carb did you notice if the needle was made of brass or plastic?

If it is plastic you will need a new brass needle. I don't have the part number in front of me at the moment.

The superglue is used to seal the main jets into place. I use a pick or small bladed screwdriver to wiggle on them to see if they are loose. If they are loose, remove them ONE AT THE TIME, since they are location specific, put a small amount of super glue on the o-rings and push them back in place taking care not to get glue into the orfice. Do the other jet and your done.

I have had brand new JD's in the crate doing the same thing you describe. Let me know if you need the number to the brass needle valve.

Ruggs, this answer is for you.
***"is that the trick where i pull the plug and use a screw driver and rotate the piston till its at TDC? where the screw driver is at its farther point outward?"***
Yes, sorta, kinda! But there are 2 points in the rotation of the crankshaft where that will occur, if you don't get the right spot of the 4-stroke cycle, one of the valves will not be in the right position to check/adjust the clearance.
The "right spot" is at Top Dead Center on the COMPRESSION stroke, and then turn the engine further until the screwdriver drops down 1/4" into the cylinder.
You can tell if the engine is in the right spot by "shaking" the rocker arms and/or looking at the valve springs.
If the engine is at TDC on the COMPRESSION stroke, both valve springs of the cylinder will be fully extended and you will feel "looseness" when you shake the rocker arms.
If the engine is at TDC on the EXHAUST stroke, the exhaust valve spring will be depressed and appear shorter than the intake valve spring. You will also observe that there is no looseness in the rocker arm on the exhaust valve.

mcherchio, you need to start a thread of your own now to continue pursuit of your problem. I should have suggested that right from the start but sometimes posters get intimidated if you make that suggestion right from the start because they feel they are being chided or brushed off. Surely you understand now how hijacking an existing thread can lead to confusion.
I mean, currently, I'm talking to two people about 2 different machines. If this keeps up........I'll soon be talking to myself.
Just fix yourself a thread for your problem and we will pursue it there. We have "borrowed" ruggs' thread long enough. :^)

Thanks Mownie, I have set new question to continue this! your a great reference, I truly appreciate it!

After a lot of hassling without some sort of tool to hold the flywheel, I figured a way to hold it and was able to get the bolt off, I looked inside and the flywheel key matched perfectly with the crankshaft?

I don't need to remove the flywheel to see the lining of the crankshaft with the flywheel, correct?

I took off the valve cover but I am not sure what I am suppose to be measuring? The distance from the end of the valve to where? I know what the valve, spring, rocker, push rod is but not sure what measurement I am suppoose to take.

Any help would be appreciated.

ruggs, if you want a service manual, e-mail me. I don't have your e-mail address, but you have mine.

Sent you an email message through the forums mownie with my email address.

Yes I have a 1975 wheelhorse with a 8 hp kohler engine recently put a new piston and rings in it. Bought the kit for it. Put it back together and she wont start. She gets spark but its not igniting the fuel even with starting fluid. So I'm guessing its a timinig probledm. my idiot friend had the flywheel and magnito off and when he put them back on wasnt sure what position magnito went and the flywheel had a real strong magnetic pull. More than before. please help. thanks.

lose idiot friend and starting fluid. get model number/type/etc. off engine I.D. Plate, go to Kohler engine website, d/l a service manual for that particular engine. Follow flywheel installation procedure closely while making sure that mating part are first absolutely clean, including the keyway. Apply correct torque per manual. good luck.