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Briggs and stratton model 33R877003-G1 will only run with air intake almost all the way covered

#1

O

ohiobob

I have a craftsman rider with a BS engine 33R877003-G1 that just stopped running while mowing. When I try to start it it just cranks but I can cover the air intake tube and it will start but when I remove my hand it dies.It is like its getting to much air.I covered the intake with tape and it ran for awhile.It I readjusted the valves cleaned the carb.Thanks for any help you can give me.


#2

sgkent

sgkent

check the fuel level and supply. Sounds like it is out of fuel, or something is obstructing the fuel supply to it. Loosen the tank cap, wait 5 minutes and see if that helps any.


#3

O

ohiobob

I have checked the fuel supply everything is good. Someone else said it could be a plugged beather on th engine.


#4

D

DaveTN

Just having available fuel supply from the tank to the carb
doesn't mean the carb is actually working efficiently. I would
disassemble the carb and boil it out with some solution and
try again. Sounds like "fuel starvation" even tho fuel is there.
Just not able to use it. Welcome to the LMF!


#5

O

ohiobob

Thanks I'll try that and let you know.


#6

B

bertsmobile1

If it only runs with the air supply almost blocked off then you have one of 2 problems
1) not enough fuel getting in to make a combustable air:fuel ratio .
2) air entering after the carb diluting the air:fuel ratio

So start with saturating the area between the carb & the engine with WD40 while the engine is running
Work the governor so the engine revs up and backs off
Clouds of white smoke = air leak

After that remove the carb and clean it


#7

O

ohiobob

bertsmobile1 said:
If it only runs with the air supply almost blocked off then you have one of 2 problems
1) not enough fuel getting in to make a combustable air:fuel ratio .
2) air entering after the carb diluting the air:fuel ratio

So start with saturating the area between the carb & the engine with WD40 while the engine is running
Work the governor so the engine revs up and backs off
Clouds of white smoke = air leak

After that remove the carb and clean it
Click to expand...
Thanks I'll try to get to run long enough to do that.


#8

O

ohiobob

bertsmobile1 said:
If it only runs with the air supply almost blocked off then you have one of 2 problems
1) not enough fuel getting in to make a combustable air:fuel ratio .
2) air entering after the carb diluting the air:fuel ratio

So start with saturating the area between the carb & the engine with WD40 while the engine is running
Work the governor so the engine revs up and backs off
Clouds of white smoke = air leak

After that remove the carb and clean it
Click to expand...
I did that today and no white smoke took carb apart cleaned it even ran small wire thru ports its still doing the same thing. I'm lost never had anything like this.


#9

B

bertsmobile1

ohiobob said:
I did that today and no white smoke took carb apart cleaned it even ran small wire thru ports its still doing the same thing. I'm lost never had anything like this.
Click to expand...
OK we have ruled out a massive air leak at the carb or manifold
did you clean it according to the instructions at outdoor power info if not then it is not clean
Pull the blower housing off and have a good look at the head gasket joint for signs of leakage ( wet or exhaust stains )
If you have a can of carb cleaner, start the engine then spray SHORT shots of carb cleaner down the carb throat.
Note the engine will knock a bit when you do this but don't worry about that.
If it will run for about a minute with continual short shots of carb cleaner then that suggest a fuel supply problem
Check that the carb solenoid plunger retracts fully when the key is in the on position .
If it is a 2 wire solenoid flick it around and make sure it stays retracted .

Let us know how you go


#10

sgkent

sgkent

if the air filter were clogged, it would make the fuel mixture too rich. His issue is the opposite, the mixture is too lean. Although not directly related, I had a set external metering jet unscrew and fall off an edger carb. It only ran when I choked it because of the air leak it caused. I would look closely at the carb, hoses etc., to be sure nothing is missing. That said, if choking the engine by putting their hand over the carb makes it run, then the problem is too lean a mixture, the goal has to be finding the cause of that. It can include bad fuel hose, filter, some defect in the carb, defect in a fuel pump if there is one, cracked manifold, loose manifold, crack in a head, blown head gasket, etc.. Anything that can affect the air to fuel ratio by either letting in too much air or too little fuel. Just choking the carb can cause enough vacuum to pull lots of fuel in. That compensates for not enough fuel or too much air. I do it all the time when running my leaf blower dry of fuel. I drain the tank and it runs off the fumes in the tank, fuel in the hose, and crankcase for about a minute. Then it starts to stumble as it runs out of fuel so I choke it, and it runs another 30 seconds or so because I am artificially affecting the air to fuel mixture. A hand over the carb makes the mixture richer.


#11

B

bertsmobile1

ohiobob said:
You act like I don't know how to clean the carb adj valves I know it can be done incorrectly but what gives you the right to say I don't know what I'm doing. Like I said if you are so good you would give advice not sarcasm and put people down without even knowing them
Click to expand...
Before this gets into a very personal slanging match Ohio Bob, you have to realize we have nothing to go on but what you have typed and have no idea of your technical understanding or abilities
We have had people tell us the they cleaned the carb when all they did was to spray the outside with throttle body cleaner and a bristle brush
Others will have "pulled tit apart & cleaned it" which ended up being dropping the float bowl & tossing out the bad fuel .
And most people will consider a carb clean if they poke the straw into every hole an some goop comes out some where else .
So the assumption is always the poster has no idea what they are doing till it is confirmed otherwise which is why I put the reference to the Outdoor Power Info page in post # 9 so you would know what we consider to be a properly cleaned carb.

I also asked you to do another test in post # 9
The way I work here, is I ask people to do things that all of the posters should be able to follow as we rule a cause in or out.
Normally there is nothing further from me til the question I posed has been answered or the test done & results posted .

In reply # 6 I explained what was happening and then proceeded to start to diagnose the reason for it .
No one here is deliberately trying to make you look stupid we are here to help you get your mower fixed .


#12

O

ohiobob

bertsmobile1 said:
OK we have ruled out a massive air leak at the carb or manifold
did you clean it according to the instructions at outdoor power info if not then it is not clean
Pull the blower housing off and have a good look at the head gasket joint for signs of leakage ( wet or exhaust stains )
If you have a can of carb cleaner, start the engine then spray SHORT shots of carb cleaner down the carb throat.
Note the engine will knock a bit when you do this but don't worry about that.
If it will run for about a minute with continual short shots of carb cleaner then that suggest a fuel supply problem
Check that the carb solenoid plunger retracts fully when the key is in the on position .
If it is a 2 wire solenoid flick it around and make sure it stays retracted .

Let us know how you go
Click to expand...

bertsmobile1 said:
Before this gets into a very personal slanging match Ohio Bob, you have to realize we have nothing to go on but what you have typed and have no idea of your technical understanding or abilities
We have had people tell us the they cleaned the carb when all they did was to spray the outside with throttle body cleaner and a bristle brush
Others will have "pulled tit apart & cleaned it" which ended up being dropping the float bowl & tossing out the bad fuel .
And most people will consider a carb clean if they poke the straw into every hole an some goop comes out some where else .
So the assumption is always the poster has no idea what they are doing till it is confirmed otherwise which is why I put the reference to the Outdoor Power Info page in post # 9 so you would know what we consider to be a properly cleaned carb.

I also asked you to do another test in post # 9
The way I work here, is I ask people to do things that all of the posters should be able to follow as we rule a cause in or out.
Normally there is nothing further from me til the question I posed has been answered or the test done & results posted .

In reply # 6 I explained what was happening and then proceeded to start to diagnose the reason for it .
No one here is deliberately trying to make you look stupid we are here to help you get your mower fixed .
Click to expand...
AS I said in post # 6 I tried that and it didn't help yes I cleaned the carb according to outdoor power and checked the head gasket might be a leak at head gasket.I just don't think it was necessary for him to keep making rude stupid remarks as cleaning in crock pot I have work on a lot of mowers and know of what I'm doing I just ran into something I;ve never seen before.Thanks for your help I will get it fixed I just thought maybe someone could help.


#13

B

bertsmobile1

The only time I have come across this problem at your magnitude it ended up being a loose rubber tip on the fuel solenoid .
However I never jump to a "fix" before doing a proper diagnosis .
Slomo has just found out about boiling carbs to clean them so had become a bit too enthusiastic advocate for this method, hence the crock pot .
It could also be a problem with the throttle not opening fully but as you know proper diagnosis starts with eliminating the most common then working your way down to the obscure


#14

O

ohiobob

bertsmobile1 said:
The only time I have come across this problem at your magnitude it ended up being a loose rubber tip on the fuel solenoid .
However I never jump to a "fix" before doing a proper diagnosis .
Slomo has just found out about boiling carbs to clean them so had become a bit too enthusiastic advocate for this method, hence the crock pot .
It could also be a problem with the throttle not opening fully but as you know proper diagnosis starts with eliminating the most common then working your way down to the obscure
Click to expand...
OK I put a new head gasket on reset valves same problem I don't know what else to check no air leaks between carb and motor I checked it like the said.


#15

sgkent

sgkent

something changed the air to fuel mixture the day it started running goofy. Here is an example of the jet that fell out of mine. All that was left was a small threaded hole that it screwed into. Looking at it first glance it looked normal then I realized something was missing. It is small, maybe 3/8" long. If something like this fell off the exterior of your carb, it would cause problems like you have.

640018.jpg


#16

O

ohiobob

sgkent said:
something changed the air to fuel mixture the day it started running goofy. Here is an example of the jet that fell out of mine. All that was left was a small threaded hole that it screwed into. Looking at it first glance it looked normal then I realized something was missing. It is small, maybe 3/8" long. If something like this fell off the exterior of your carb, it would cause problems like you have.

640018.jpg
Click to expand...
That jet is still in the carb when I took it apart to clean it Thanks


#17

B

bertsmobile1

Other way round SG
Something is stopping fuel getting in or letting too much air in


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