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Brigss 20hp V twin

#1

S

skiftcky

I have a 20 HP Briggs and Stratton V twin on a JD L120. Problem 1 is that it seems to be catching when I try to turn it over. sometimes it will turn fine other times the starter will catch and release. Second Problem. it will not start... I get some oil dripping on the right side exhaust but not much. Could this be a blown gasket or warped head or piston wall?


#2

Grassbandit

Grassbandit

I have a 20 HP Briggs and Stratton V twin on a JD L120. Problem 1 is that it seems to be catching when I try to turn it over. sometimes it will turn fine other times the starter will catch and release. Second Problem. it will not start... I get some oil dripping on the right side exhaust but not much. Could this be a blown gasket or warped head or piston wall?

does the engine turn freely if you do it by hand?
are you sure the battery is fully charged?


#3

EngineMan

EngineMan

Take the plug(s) out and then see if you turn it.


#4

S

skiftcky

I've removed both plugs and turned it. Still does the same. and yes it turns freely by hand, it's not seized up. The battery was brand new and had a full charge per my multi meter however in trying to get it started I wore it down a bit and now have it on the charger (2 amp slow). My main concern is the oil coming from the exhaust on the right (facing while sitting at wheel) I'm worried this might be an internal engine issue that is keeping it from starting. Also, I already pulled the carb and cleaned it, it is getting spark. I also double checked the gap on the plugs cleaned of the coils and magnets.


#5

EngineMan

EngineMan

Then it may well be time to look at the oil leak and see where its coming from, post up the engine numbers.


#6

Fish

Fish

Was 1 of the plugs "oily"??????


#7

S

skiftcky

Yes the plug was oily, the same one where the oil is coming from exhaust. As far as a leak, it is coming from the actual exhaust pipe I took it off and the inside of the pipe is saturated as well as the exhaust manifold ( internally)


#8

Fish

Fish

Probably have at least a blown head gasket, but maybe more. Post the engine's model/type numbers.


#9

S

skiftcky

Model 40677 type 0139 E1


#10

Fish

Fish

give the full story behind this mower please...


Like, "I just bought this mower from a friend and......."

I tried this........ And it didn't work...........


#11

Carscw

Carscw

Put your finger in the spark plug hole and spin the engine over does air try and come out. Also look in the hole can you see the piston going up and down

(( cowboy up and get over it ))


#12

S

skiftcky

Did the finger in the spark plug hole and it does push air in and out. I got the mower from a guy who said it he went out to fire it up and it just wouldn't start, he said it ran til he shut it off before that. I took the carb off cleaned it out down to the float, pulled and regapped plugs, sanded and re gaged the coils, made sure oil was good it's pretty much brand new, fresh gas and filter, he had a few wires on the harness that were twist tied and electric taped. I don't like that so I butt connected them all. It has spark, airflow, fuel flow, and as far as I can tell it has compression. I just don't know if that oil coming from my exhast might be loosing enough compression or putting oil into the compression chamber which won't let it ignite. One other thing when it turns over I get no smoke from the exhaust at all which leads me to believe that the mixture isn't combusting at all.


#13

Fish

Fish

Pull both of your valve covers and tell us what you see.


#14

S

skiftcky

I think I may have it figured out. Earlier I wet out pulled the valve covers, gap is fine on them. I talked to an old timer and he said to check the flywheel key to see if it broke or slipped. I will do this tomorrow since my wife "needs" to garage her car. I have a nice carport in back but I live in the south, its been wet, and mosquitos have drained me. I will keep plugging away.


#15

EngineMan

EngineMan

Not sure if you have a parts list, if not here it is.

https://www.dropbox.com/s/u0pxsd708cikldt/406700-ms2986-1004.pdf


#16

Fish

Fish

Have you just tried pouring a dribble of fuel directly into the carb to see what happens, your afterfire solenoid might not be working.


#17

S

skiftcky

Apologize for not coming back on yesterday but I was swamped with other stuff. I did put some fuel into the carb and it shot a 3 foot flame out, back fired then shot flame out of the exhaust pipes. I'm thinking this is a timing issue but cannot find anything on how to set the timing on this engine.


#18

Fish

Fish

Well, if the valves move normally, then I would vote for the flywheel key being sheared.


#19

S

skiftcky

nope pin is in place and locked in.


#20

M

motoman

Loose sump bolts will let oil seep out. If the valve covers are still off look at the position of the valve guides in relation to one another. Sometimes the exhaust guide moves up in the head and cause problems


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