Compression issue after rebuild

[Tbone0106]

Looking all the way back at the original post, it sure sounds like the wrong spark plug. As in too long. As in the piston is smacking the plug electrode.

Barring that, I'd check VERY carefully that the keyways on the top of the crankshaft and the flywheel align perfectly. There is a key in there to achieve that alignment, but only the proper torque on the flywheel nut will secure it sufficiently to the crankshaft. If the torque is too low, the flywheel will shift the very first time the spark plug fires, and that key will shear. Then your timing is gone, and that engine will never start.

 

[Emsguy]

Looking all the way back at the original post, it sure sounds like the wrong spark plug. As in too long. As in the piston is smacking the plug electrode.

Barring that, I'd check VERY carefully that the keyways on the top of the crankshaft and the flywheel align perfectly. There is a key in there to achieve that alignment, but only the proper torque on the flywheel nut will secure it sufficiently to the crankshaft. If the torque is too low, the flywheel will shift the very first time the spark plug fires, and that key will shear. Then your timing is gone, and that engine will never start.

Thanks. I will check the flywheel key tonight and see if that fixes the issue

 

[hlw49]

I watched her video and she was off on several key things. First off on the 33 cubic inch engine the valve setting is .003 to .005 on both valves. Next you always torque the pan and head gaskets in steps. I always do it in 1/3rds. She did not torque the rocker arm adjusting nut set screws. They torque to 45 inch lbs. Once you torque the set screws you should always recheck the valve clearance as it can change. Other than that she was pretty much on track. Those pan gaskets can be a pain in the arse to get off. I use gasket remover and that helps a lot.

 

[StarTech]

I watched her video and she was off on several key things. First off on the 33 cubic inch engine the valve setting is .003 to .005 on both valves. Next you always torque the pan and head gaskets in steps. I always do it in 1/3rds. She did not torque the rocker arm adjusting nut set screws. They torque to 45 inch lbs. Once you torque the set screws you should always recheck the valve clearance as it can change. Other than that she was pretty much on track. Those pan gaskets can be a pain in the arse to get off. I use gasket remover and that helps a lot.

Where you come up with both valve are the same? Here is the specs on my personal engine.

And yes the clearances tend to change as you torque the set screws that why you have to slightly tighten them wile setting the clearance to take thread slack.

 

[jimbomower]

Fouled spark plug! Try a new one...not used!

 

[thesilentone]

So many issues here, it's difficult to know where to start. The engine cranked without the spark plug, then no good once the plug is fitted ?

Is the spark plug the correct length and spec ? Is the battery good ?

Backfiring into the exhaust and carb sounds like timing all day long, however it's usually one or the other. (carb or exhaust), however it maybe dirt in the carb, this shows up as a similar problem.

What not just set the valve clearances to spec, that is what the specs are for !

This is a pretty basic big-pot motor, what broke the con rod ?

 

[Emsguy]

So many issues here, it's difficult to know where to start. The engine cranked without the spark plug, then no good once the plug is fitted ?

Is the spark plug the correct length and spec ? Is the battery good ?

Backfiring into the exhaust and carb sounds like timing all day long, however it's usually one or the other. (carb or exhaust), however it maybe dirt in the carb, this shows up as a similar problem.

What not just set the valve clearances to spec, that is what the specs are for !

This is a pretty basic big-pot motor, what broke the con rod ?

Had the engine on its side after rebuilding all component parts. Didn’t realize all the oil leaked out and didn’t check the oil. Still no luck on it starting. Just put a new spark plug in and still no start. I am running out of ideas here. The last thing I can think of is taking a look at the carb but I literally just purchased a brand new one (Briggs and Stratton) so I highly doubt that’s it. When you start the engine, are you suppose to feel air come out of the air intake as well as air being pulled in? Oh and as in rebuilding component parts, I mean rebuilding everything on the frame of the tractor. Maybe I am having a hard time understanding the top dead center thing. The YouTube video I follow showed setting the valve clearances while one valve is completely opened.

 

[Emsguy]

So many issues here, it's difficult to know where to start. The engine cranked without the spark plug, then no good once the plug is fitted ?

Is the spark plug the correct length and spec ? Is the battery good ?

Backfiring into the exhaust and carb sounds like timing all day long, however it's usually one or the other. (carb or exhaust), however it maybe dirt in the carb, this shows up as a similar problem.

What not just set the valve clearances to spec, that is what the specs are for !

This is a pretty basic big-pot motor, what broke the con rod ?

Valves are set to spec per the service manual.

 

[thesilentone]

Had the engine on its side after rebuilding all component parts. Didn’t realize all the oil leaked out and didn’t check the oil. Still no luck on it starting. Just put a new spark plug in and still no start. I am running out of ideas here. The last thing I can think of is taking a look at the carb but I literally just purchased a brand new one (Briggs and Stratton) so I highly doubt that’s it. When you start the engine, are you suppose to feel air come out of the air intake as well as air being pulled in? Oh and as in rebuilding component parts, I mean rebuilding everything on the frame of the tractor. Maybe I am having a hard time understanding the top dead center thing. The YouTube video I follow showed setting the valve clearances while one valve is completely opened.

If everything is assembled correctly, as they are keyed, it's simply a case of lining up the timing marks on the crank and cam shaft gears/teeth.

There maybe a little 'blow back' into the carb when cranking, as there maybe a little lag, lead and overlap on the valves, to be honest, I don't really know.

 

[Emsguy]

If everything is assembled correctly, as they are keyed, it's simply a case of lining up the timing marks on the crank and cam shaft gears/teeth.

There maybe a little 'blow back' into the carb when cranking, as there maybe a little lag, lead and overlap on the valves, to be honest, I don't really know.

Do you know if the cam shaft style would make a difference? My old one is rounded at the end while the new one is slotted. From what I understand, the slotted one is also used for an engine with an oil pump.
Old one