Now the mower will not crank!

[TLloyd]

I finally got the drive belt in place!
Then I had to straighten a bent bracket and add two washers for a pulley to get lined up. Was able to get the motor running, I went for a drive and everything looks, feels and smells like it’s all good!
NOW I’m back to the motor won’t start!
Has my engine jumped out of time?
The motor starts to spin then I guess the spark plug fires, I hear a loud pop and the engine goes backwards. I hit the key and it will be spinning one way, but it’s like when the compression gets into the cylinder the engine turn slowly till it gets past that and then it’ll spin kind of freely till it hits compression again and it will slowly go past that. If the gas fires during compression it moves engine backwards!
Where do I start fixing this problem!
Lloyd

 

[Auto Doc's]

Hello TLoyd,

It helps to have the product label information off of the machine, so we know what engine you have and how to better help you.

Rider engines don't just jump timing or shear a flywheel key.

When it comes to push mowers, they will shear a flywheel key when the blade strikes a hard object and suddenly stops the engine.

From your brief description it sounds like this engine needs the valves adjusted properly. When the valve lash is too wide, the compression release doesn't work efficiently and the engine fights higher than normal compression. This will cause a stop in cranking and reverse rotation issues.

 

[TLloyd]

Hello TLoyd,

It helps to have the product label information off of the machine, so we know what engine you have and how to better help you.

Rider engines don't just jump timing or shear a flywheel key.

When it comes to push mowers, they will shear a flywheel key when the blade strikes a hard object and suddenly stops the engine.

From your brief description it sounds like this engine needs the valves adjusted properly. When the valve lash is too wide, the compression release doesn't work efficiently and the engine fights higher than normal compression. This will cause a stop in cranking and reverse rotation issues.

I ordered red RTV permagasket and new feeler gauges (old ones got rusted ). As soon as they come in I will check the lash.
I saw a video that (if I remember right) showed, while rotating the engine slowly, where there is supposed to be tiny movement that you'd notice on the rocker arm that would indicate your compression release was still working. Should I also be looking for that when I have the valve cover off?

 

[Auto Doc's]

Hello TLloyd,

Let us know what engine model you are working on. Otherwise, it is all guesswork. Crystal ball is broken and my lucky socks have a hole in them.

Briggs and Stratton? Numbers are stamped into a valve cover.

Kohler? Usually have a product label on the engine fan cover.

Kawasaki? Usually have a product label on the engine fan cover.

 

[slomo]

I ordered red RTV permagasket

Please think, of the next guy, that has to remove that cover. Use the OEM paper/rubber gasket if at all possible. Or a sealant that doesn't fully harden.

RTV is amateur hour in my book. Red is the wrong color type for oil anyway. Your mower, use what you like.

 

[Auto Doc's]

I agree with slomo,

At the very most I will only use ultra gray very thinly on a good gasket to reseal a valve cover, but not just straight RTV by itself. It takes prying the covers off if you have to readjust valves later.

The biggest problem with RTV is the people who apply too much of it.

That excess comes off inside and ends up in the oiling system and that is never good.

 

[Tiger Small Engine]

I ordered red RTV permagasket and new feeler gauges (old ones got rusted ). As soon as they come in I will check the lash.
I saw a video that (if I remember right) showed, while rotating the engine slowly, where there is supposed to be tiny movement that you'd notice on the rocker arm that would indicate your compression release was still working. Should I also be looking for that when I have the valve cover off?

The tiny “bump” that you look for to be sure the compression release is working correctly is in fact the whole key to verifying if the compression release mechanism is broken or working on the camshaft. This is how I check when needed.

 

[slomo]

Don't know how many valve covers I've tried to remove. Globs of RTV all over the engine. End up bending and replacing the valve cover because it's "stuck on Band-Aid brand".

Soon as I see RTV, I think to myself, here we go. The entire mower now has to be gone over and inspected.

 

[TLloyd]

Hello TLloyd,

Let us know what engine model you are working on. Otherwise, it is all guesswork. Crystal ball is broken and my lucky socks have a hole in them.

Briggs and Stratton? Numbers are stamped into a valve cover.

Kohler? Usually have a product label on the engine fan cover.

Kawasaki? Usually have a product label on the engine fan cover.

B&S 33R877 0033 G1

 

[StarTech]

I agree with slomo,

At the very most I will only use ultra gray very thinly on a good gasket to reseal a valve cover, but not just straight RTV by itself. It takes prying the covers off if you have to readjust valves later.

The biggest problem with RTV is the people who apply too much of it.

That excess comes off inside and ends up in the oiling system and that is never good.

You don't have to pry covers off when sealed with RTV; You shear them off. Then you cleanup the mating surfaces by removing the old RTV.

And yes inexperience people use too much RTV. They also don't allow the RTV cure overnight before adding oil and cranking up the engines. RTV will not cure once oil contacts it resulting in early leaks.