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No Compression

#1

Hottech

Hottech

My Briggs and Stratton 11092-0113 f1 single cylinder overhead valves has no compression. Replaced head gasket,seated and adjusted valves. Was wondering if I need to replace the camshaft? Would the camshaft cause me not to have compression?


#2

R

Rivets

Before tearing into the engine, I would check for a blown head gasket.


#3

StarTech

StarTech

Please verify model number posted as I find no Briggs with that model number. Even just using the type number; nothing is close.

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#4

I

ILENGINE

@StarTech My suspicions is the model is a 111P02-0113-F1. that model has the camshaft with the plastic gear. So there is the possibility of a slipped gear or slipped teeth or broken teeth.


I would pull the valve cover back off and also pull the spark plug. Then either find something to indicate the piston position or shine a light down the spark plug hole and while turning the crank what the valves. What you are looking for is the relationship between the piston position with the valves. Like exhaust valve open with the piston half way down the cylinder.

The idea is to find if the piston and the valves appear to be timed correctly without having to tear down the engine. And with a compression release mechanism on the camshaft feel of compression may not be accurate. Worked on a generator a few years back that had 5% leakdown when tested with a leakdown gauge, but only showed 5 psi of compression.


#5

S

slomo

Hottech said:
Replaced head gasket
Click to expand...


#6

sgkent

sgkent

how are you testing for compression?


#7

S

slomo

Hottech said:
My Briggs and Stratton 11092-0113 f1 single cylinder overhead valves has no compression. Replaced head gasket,seated and adjusted valves. Was wondering if I need to replace the camshaft? Would the camshaft cause me not to have compression?
Click to expand...
Have you tested for no compression? As in with a gauge?

A bad cam could cause no compression.

Remove valve cover and turn the engine over. See if the valves open and close. Maybe the rockers are not set proper? Bent push rods?

Which stroke were the valves set on? There are 2 TDC strokes on a 4 smoke engine.

Did you lap the head and head gasket area prior to installing the new head gasket? This needs to be checked.


#8

S

shinkle

slomo said:
Have you tested for no compression? As in with a gauge?

A bad cam could cause no compression.

Remove valve cover and turn the engine over. See if the valves open and close. Maybe the rockers are not set proper? Bent push rods?

Which stroke were the valves set on? There are 2 TDC strokes on a 4 smoke engine.

Did you lap the head and head gasket area prior to installing the new head gasket? This needs to be checked.
Click to expand...

How do you know which TDC stroke to use to set valves? Is there a way to determine which stroke is the correct one to use?


#9

Scrubcadet10

Scrubcadet10

shinkle said:
How do you know which TDC stroke to use to set valves? Is there a way to determine which stroke is the correct one to use?
Click to expand...
i just do one valve open, one valve closed, adjust the valve that is closed.


#10

sgkent

sgkent

one should rotate the engine and watch the valves to figure where TDC is on the compression stroke, then if the manufacturer specifies a specific drop past that measure the piston drop before adjusting the valves.


#11

Hammermechanicman

Hammermechanicman

Scrubcadet10 said:
i just do one valve open, one valve closed, adjust the valve that is closed.
Click to expand...
Yup, works every time.


#12

B

bertsmobile1

First thing is to rotate the engine 2 full cycles with the rocker cover off and watch the valves moving
Both valves move the same distance & sit the same distance out.
A rookie mistake is to set the valve lash on the exhaust stroke, not compression stroke which will cause zero compression


#13

S

slomo

Or thinking the EX valve is the intake, LOL. I caught myself once doing this like an idiot.


#14

B

bertsmobile1

slomo said:
Or thinking the EX valve is the intake, LOL. I caught myself once doing this like an idiot.
Click to expand...
no comment


#15

S

shinkle

Hammermechanicman said:
Yup, works every time.
Click to expand...
So you don't try to determine compression stroke or exhaust stroke?


#16

Scrubcadet10

Scrubcadet10

shinkle said:
So you don't try to determine compression stroke or exhaust stroke?
Click to expand...
I never have.... one valve open (which means that rocker arm will be pushing that valve spring down) adjust the other valve. Repeat the process.


#17

Hammermechanicman

Hammermechanicman

shinkle said:
So you don't try to determine compression stroke or exhaust stroke?
Click to expand...
No need to. All you are wanting is to adjust the valve while the tappet is on the base circle, or heel of the cam. If one valve is completely open the other valve is closed and tappet is somewhere on the base circle of the cam. Doesn't matter where. Same for the other valve. Only engines i use a timing mark to position flywheel are the stihl 4mix engines.


#18

StarTech

StarTech

Hammermechanicman said:
No need to. All you are wanting is to adjust the valve while the tappet is on the base circle, or heel of the cam. If one valve is completely open the other valve is closed and tappet is somewhere on the base circle of the cam. Doesn't matter where. Same for the other valve. Only engines i use a timing mark to position flywheel are the stihl 4mix engines.
Click to expand...
And that because they use the same camshaft lobe, just they didn't need a special .004 feeler gauge as I can lose it every so often. I finally got another replacement but I am still awaiting the octagon adjustment tool. I have been lucky so far as to not need it but I know I will.


#19

L

lbrac

At TDC on the compression stroke, both valves will be closed (on their cam base circles). This is normally the proper position for adjusting the valves. I usually remove the spark plug when troubleshooting with a cool engine and put my finger over the plug hole while manually turning over the engine. There should be pressure on the compression stroke, and vacuum on the power stroke, with both valves closed, except near BDC. The exhaust stroke will have very slight pressure with the exhaust valve open until near TDC; and the intake stroke will have a very slight vacuum when the throttle is closed and the intake valve is open until near BDC.


#20

J

jagg2236

Hottech said:
My Briggs and Stratton 11092-0113 f1 single cylinder overhead valves has no compression. Replaced head gasket,seated and adjusted valves. Was wondering if I need to replace the camshaft? Would the camshaft cause me not to have compression?
Click to expand...
My 2cyc Husqvarna 350 chainsaw goes through pistons & cyl every year. With that said pull the head, check/replace the exh valve, check the cyl wall for scores. Replace the cyl & piston. BTW my problem might be I've been replace my cyl/piston with cheap "China" ebay stuff. Next time I'll get OEM. Whole other Husq parts subject???


#21

R

Rivets

Exhaust valve on a 2-cycle engine??


#22

Scrubcadet10

Scrubcadet10

Rivets said:
Exhaust valve on a 2-cycle engine??
Click to expand...
i wonder if he means the decompression button on the head for easier starting.....


#23

StarTech

StarTech

He has no idea what the OP is working on.

As for the 350 some had decomp valve and others didn't, depend on the build.


#24

I

ILENGINE

Rivets said:
Exhaust valve on a 2-cycle engine??
Click to expand...
I think Jagg threw in something unrelated to the original post when he mentioned his 350 chainsaw, and then went on and discussed the original engine in the same sentence. Hence the confusion behind the exhaust valve on a 2 stroke chain saw.


#25

R

Rivets

He should know better if he’s anything more than a DIY guy. Now I’ll get ripped for questioning the post. Oh well, been there done that.


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