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Briggs and Stratton vanguard 20 HP V twin spitting fuel

#1

Ianv

Ianv

A video of the engine running
https://youtube.com/shorts/iYbA8e2mHao?feature=share
Can’t put the filter back on without it stalling, won’t rev out all the way, spits gas out of the carb and Black smoke coming out of the exhaust


#2

I

ILENGINE

Sounds like running on one cylinder. possible dropped exhaust push rod or intake valve seat came loose.


#3

H

hlw49

Don't think a dropped exhaust valve would cause that since it is not building compression to spit back. It would be rare for an intake seat to come loose since in coming fuel would keep the valve and seat cooler it is usually the exhaust valve seat that comes out. Exhaust push rod out could cause it or even a worn out cam. Pull the valve cover and look see. If the push rods are intact and valves adjusted properly turn the engine over by hand and makes sure the cam is opening the valves like it should.


#4

Ianv

Ianv

hlw49 said:
Don't think a dropped exhaust valve would cause that since it is not building compression to spit back. It would be rare for an intake seat to come loose since in coming fuel would keep the valve and seat cooler it is usually the exhaust valve seat that comes out. Exhaust push rod out could cause it or even a worn out cam. Pull the valve cover and look see. If the push rods are intact and valves adjusted properly turn the engine over by hand and makes sure the cam is opening the valves like it should.
Click to expand...
Valves checked out


#5

Scrubcadet10

Scrubcadet10

Does fuel continue to flow up and out of the carb if you shut it down? Im wondering if you have float/needle issue inside the carb, i have seen them bad enough where they run way too rich.


#6

Ianv

Ianv

just cleaned out the carb everything is good still spitting out gas though out of one side

A video
https://youtube.com/shorts/4ZESyPeyAKI?feature=share


#7

S

slomo

Ianv said:
just cleaned out the carb everything is good still spitting out gas though out of one side

A video
https://youtube.com/shorts/4ZESyPeyAKI?feature=share
Click to expand...
You need to pressure test the needle and seat inside the carb. Should hold 7psi for a good while. Looking at it and spraying cleaner does not verify the needle and seat is working proper.

Another thing you could do. Remove the carb WITH fuel line attached. Hold carb at same engine mounted level. See if fuel pours out the engine side of the carb. Guess depending on how you hold it, could come out the air filter side too.

Can also remove the carb. Take a piece of fuel line. Connect it to the carb. Blow into the fuel line. Listen for air leakage inside the carb.


#8

S

slomo

I hear a clinking noise. Like a loose valve seat possibly. Pull the head and see what you got.


#9

Ianv

Ianv

It’s getting spark but it’s only running on one cylinder


#10

S

slomo

Ianv said:
It’s getting spark but it’s only running on one cylinder
Click to expand...
Where is the spark at exactly? One cylinder has spark and the other doesn't? So one cylinder is running, the other is dead? Both cylinders have spark?


#11

S

slomo

Ianv said:
Valves checked out
Click to expand...
What check procedure was used? Did you see them and call it good? Yup they're in there.....

You need to elaborate a little more so we can help you.

Did you check the clearances using your engine manual?


#12

S

slomo

Ianv said:
A video of the engine running
https://youtube.com/shorts/iYbA8e2mHao?feature=share
Can’t put the filter back on without it stalling, won’t rev out all the way, spits gas out of the carb and Black smoke coming out of the exhaust
Click to expand...
Can you sit down, take a breath and write out what is exactly wrong with this engine?

Your sentence fragments are tough to cipher out.

Can you post all the engine numbers? Need more than the first and second digits.


#13

S

slomo

Valves check out
Carb is good
Has spark somewhere??

What is the compression value?


#14

H

hlw49

When you had the valve cover off did U turn the engine by hand and watch the valves to make sure they are opening and closing like they should. Have friend that was having problems with one the would hit and run just a few licks and die. He replace the ign. modules and lifters wanted me to take a look for him. He wanted to do a cylinder leak down test which we were going to do but I suggested we take the valve cover off and turn the engine over and check the valves were opening and closing. We did this and neither exhaust valve was opening. Worn out cam. Might this be your problem? The valves can open a little but if they don't have the proper lift they won't run right.


#15

Ianv

Ianv

hlw49 said:
When you had the valve cover off did U turn the engine by hand and watch the valves to make sure they are opening and closing like they should. Have friend that was having problems with one the would hit and run just a few licks and die. He replace the ign. modules and lifters wanted me to take a look for him. He wanted to do a cylinder leak down test which we were going to do but I suggested we take the valve cover off and turn the engine over and check the valves were opening and closing. We did this and neither exhaust valve was opening. Worn out cam. Might this be your problem? The valves can open a little but if they don't have the proper lift they won't run right.
Click to expand...
Right side of the carb spitting out fuel both cylinders are getting spark but the right cylinder isn’t firing I have been through the carb the float valve was working properly I also took off the valve cover valves are tight valves are moving as they should and both cylinders have good compression when I try to run the machine with just the right cylinder it rarely fires and doesn’t stay running


#16

H

hlw49

U say the valves are tight. What is the clearance they are set on they should have somewhere between .004 and .006. Might want to check that.


#17

B

bertsmobile1

Ian
In this order
1) check the valve lash on both cylinders
They must have some clearance on the firing stroke or the compressed charge will either blow out the muffler or back through the carb
2) If the lash is OK pull the kill wires from both coils , dead cylinder suddenly starts to work = bad diode in the kill wire
3) If that makes no difference swap the coils over left to right ( Plugs as well ). Problem shifts to the other side = dead coil


#18

S

slomo

Ianv said:
I also took off the valve cover valves are tight
Click to expand...
So now the valves are tight? Thought the valves were good couple comments ago?

This is why we ask so many questions. People say for example are the cooling fins clean. I get a yes response. Later a picture of their engine gets posted and it's filthy.


#19

H

hlw49

you know a cylinder leak down test might tell you what is wrong. When you checked the valves did you turn the engine over by hand and watch the valves to make sure they were opening as much as the other side? If U take the plugs out it will make it easier to turn over.


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