4 HP briggs and stratton

[tenlizard]

but it's made in the 80s i don't think that came out yet...did it?

 

[tenlizard]

then i guess my rings are worn

 

[Affair_driven]

Came into use around 1957-8. Some changes/improvements since then but is essentially the same.
Does engine smoke?

 

[tenlizard]

it didn't smoke the last time i started it which was before christmas...the spark is fine and the carb is fine...the compression is horrible. i left the engine on my back porch under the deck. even though it didn't get any rain on it...it still rusted a little bit...idk wat could be causin this thing to only have 50 psi pressure. idk y it won't start.

 

[Affair_driven]

Compression testers don't work on Briggs engines because of Easy Spin feature.
Your getting a false positive (negative?) by using a compression tester.
The real 'proof' is in how the engine performs under driving conditions.

 

[tenlizard]

then what is the issue?

 

[Affair_driven]

Try pouring a teaspoon of gasoline directly into spark plug hole.
Try to start, no choke with throttle about 1/3 open.
Should fire up for a short burst.
Let me know what happens.

 

[THE HUNTER]

Like Affair said, the exhaust valve opening on the compression stroke is normal (at cranking speeds), it just compression release to make it easier to start.
other manufacturers use compression release too.

and it prob rusted cause of the moisture in the air.

did you leave gas in it from last year?


try the procedure that Affair said, with the gas in the spark plug hole.

 

[tenlizard]

the teaspoon of gasoline didn't work

 

[tenlizard]

and it is rusted in certain spots
none from what i can see internal. and no i drained all the gas from last year before i didn't use it. this is new gas i'm using

 

[THE HUNTER]

did the faces of the valves/valve seats have any corosion on them? its kinda hard to see unless you have a good flashlight and are looking right at it.
i had a Kohler not even pop cause the intake valve had some rust on it, cleaned the rust off, and it started up just fine.

 

[Affair_driven]

Basics first.
Did you check for spark?

 

[tenlizard]

ok...yes i did check for a spark...and no there is no corrosion on valves. i looked in cylinder and it was scorched...like there were pretty deep lines in it. what i'm going to do is rebore it with a cylinder hone. what should i do about the rings though? how much oversize should i get them? .010", .020", or .030"

 

[tenlizard]

the problem, no doubt is the compression

 

[Affair_driven]

Engine should still fire up if it has spark despite what compression may or may not be.
Try this trick. Put a couple of tablespoonfuls of sae 30 oil in plug hole. Spin it over slowly by hand a couple of revolutions to distribute oil. Add gas again and retry. NO CHOKE!!! This will have the effect of giving the rings a better seal.
If it still does not sputter at all, then something else is wrong. Spark may be blowing out.

 

[tenlizard]

that didn't get it to work either. i checked the spark with my hand and it hurt like a b1tch. but for some reason, with all my spark plugs, there is no spark on them. maybe the spark is just weak? i'm going to buy a spark tester and see if the spark is ok

 

[Affair_driven]

Make sure to use a non resistor plug.
Check ignition timing.

EDIT: As a last resort you can try starting ether, something I don't usually recommend.
Starting ether will fire under the worst of conditions and is a good troubleshooting tool.

 

[tenlizard]

i'm just going to get a spark tester for now, then i'll try ether if it says that there is a spark

 

[THE HUNTER]

the compression in the Kohler i had was so bad, nothing would fire in it, it just blew all the fuel out. then the only thing i changed was cleaning the valves, and it started right up.

are your spark plugs new?
you should be able to get a spark from them if they are clean, and your ignition is good.

 

[tenlizard]

my spark tester says that there is a good prominent spark. for some reason, it doesn't seem to be getting to the spark plug though...i'm not sure...what is the best way to test if the spark plug isn't malfunctioned?