Briggs and Stratton 5 HP Wont Start

[ProTechCharlie]

I got 30 Lbs. to 35 Lbs. Low compression. What could possibly be the cause of this? Fish, mike? The only thing I have not went over are the valves. I made a video of the valves with the piston moving for you guys. I will put a link to it as soon as it is uploaded.

 

[ProTechCharlie]

Do you guys think...that I put the lifters for the valves in backwards? As in I put the intake one for the exhaust and vice versa? Or would that even make a difference? I was watching a video on YouTube of a teardown and he made sure to point at that he marked them, intake and exhaust. Could this be causing my low compression problem?!

 

[Mikel1]

Now what were those six reasons again, just joking.
A leakdown tester would be ideal to help find the problem faster but I'm guessing you don't have one. So I would pull the head and first check the valves. When I had 30psi on this engine model it was from a stuck intake valve, a product of my own doing. I would make sure both valves are fully seating. Did you take the valves out earlier? I ask because there is usually a thicker, beefier spring on the exhaust valve which is not on the intake valve. The lifters(tappets) on my engine are identical according to part #.

 

[ProTechCharlie]

Now what were those six reasons again, just joking.
A leakdown tester would be ideal to help find the problem faster but I'm guessing you don't have one. So I would pull the head and first check the valves. When I had 30psi on this engine model it was from a stuck intake valve, a product of my own doing. I would make sure both valves are fully seating. Did you take the valves out earlier? I ask because there is usually a thicker, beefier spring on the exhaust valve which is not on the intake valve. I will take a look at the lifters in the manual.

Well, I will admit that I felt like an idiot when I seen the needle didnt even go above thirty five. I also felt my heart sink because that could mean the cylinder is bad. And that means R.I.P. for me. I took a video of the valves and piston for your enjoyment, hehe. I will have it posted here when it is uploaded. I did not take the valves out, only the tappets, or push rods, which is why I was concerned that I may have put them backwards. I know the shop has leak tester, but I would probably not be able to use it for myself. I will be back as soon as the video is done.

-Thanks, Charlie.

 

[Fish]

It sounds like your next step would be to check your valve clearances, since it sounds like you haven't. I just assumed that you had. If you don't have
the valves closing fully, your compression will just go out the open valve.

 

[ProTechCharlie]

It sounds like your next step would be to check your valve clearances, since it sounds like you haven't. I just assumed that you had. If you don't have
the valves closing fully, your compression will just go out the open valve.

That is through the breather box right? The PCV system pretty much, right? Can you give me instructions on how to do that with this engine? I guess I will need to purchase a set of feeler gauges then?

-Thanks, Charlie.

 

[ProTechCharlie]

Now what were those six reasons again, just joking.
A leakdown tester would be ideal to help find the problem faster but I'm guessing you don't have one. So I would pull the head and first check the valves. When I had 30psi on this engine model it was from a stuck intake valve, a product of my own doing. I would make sure both valves are fully seating. Did you take the valves out earlier? I ask because there is usually a thicker, beefier spring on the exhaust valve which is not on the intake valve. The lifters(tappets) on my engine are identical according to part #.

Here goes the video: https://www.youtube.com/watch?v=NkgGH0IwZx4&list=UUwqNMVMMsbcApQC8puuuzEg

 

[Fish]

That is through the breather box right? The PCV system pretty much, right? Can you give me instructions on how to do that with this engine? I guess I will need to purchase a set of feeler gauges then?

-Thanks, Charlie.

Yes, you need to get some feeler gauges, you will use them all of the time.

 

[Fish]

Ok, go back to the very first scene of your latest video, where the piston is at tdc and both valves are down.

With everything in that position, take your thumb and try to rotate each valve. If you can, then that is a major problem.

Also, it looked like you needed a tool to rotate the engine with the head off, is that true???? The thing should rotate like greased lightening.

 

[Fish]

That exhaust valve looks like it isn't closing all of the way.