Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I have been working to get an leaf loader ready for fall clean up. The 11hp briggs and stratton engine starts briefly when choked and then dies. Gas runs out and drips below. It runs all of 3 seconds before it dies. I've tried starting it without the choke but no luck there. When I bought it a week ago the previous owner started it on the first pull. It has a good spark, fresh gas, a clean air filter. With the spark plug pulled I can see the spark. I've tried starting it at half throttle, full throttle and low throttle. No difference there. I took the bowl off the carburetor and cleaned out the crud that was in there. Do I need to take the carb off and completely clean it? What setting should the throttle be at for start up? Any suggestions? the motor is a Briggs Industrial Plus model 256422 type 1015 -E1

I think you will be fine if you just take the float off and clean it from there. The nozzel is considered by most the main jet... Really it is the "highway" for the main jet. All fuel is drawn through the calibrated hole that is on the carb tower that intersects with the nozzle. At low speed(low airflow thought the carb) the draw is too small to pull full through the nozzle, At this speed of airflow the throttle shaft is nearly closed, Air has to speed up by the edge of the nearly closed throttle butterfly, thus causing fuel to be sucked/drawn from the little holes nesx to the butterfly on the inside of the carb(low speed) orifice..

Jet and orifices are usually used interchangebly. I think the best description is "low speed circut" and "high speed circut"...


Friiy

Any Progress Underdog???

<BR> niper99 wrote: I found the tool at Harbor Freight and got the carburetor off and gave it a really thorough cleaning. A few of the holes on the carb seemed to be sealed with a small bearing. But I cleaned them as best I could. I hooked it all back up and it started on the first pull. It ran really well and would throttle up and did not smoke. The after a about 1.5 minutes is died. Dead as a doornail. As if it was starved for gas. <BR><BR>I did take some photos of the carburetor while I had it off. Here they are:<BR><BR>>< <BR><BR>>< <BR><BR> >< <BR><BR><BR>

sounds like your float needle isn't opening or there's a fuel line blockage. If you have fuel at the carb, then it's likely the float needle sticking or an improperly adjusted float. Floats can be tricky business. Get the specs for yours and set accordingly. Good luck.

I'll take another look at the float and float needle. I took a Q-tip and removed most to the fluffy end and tried to polish the seat for the needle. I did not inspect or touch the needle itself. <BR>When I go to remove the bowl there is always plenty of fuel in there. And with the bowl off, its easy to lift the float with my hand, forcing the needle up into its seat where it does shut off the flow of fuel. Maybe my hand pressure (to seat the needle) is different than the force that the float exerts on its own. Are you suggesting that the needle is not closing when the float raises up and thus fuel is continuing to fill the bowl and the carb? OR that the needle might be sticking in the seat and not allowing more gas to fall into the bowl as it gets low (starving the carb of gas)? <BR>My ongoing symptom is: &quot;let is sit 5 minutes, pull the starter with the choke on, the engine starts right up and then dies&quot; <BR><BR> <BR>
This is the first time I have ever worked on a Briggs engine. I hope I'm not missing something simple/basic.

Is your gas cap vapor locking? Does it allow air into the tank as fuel is drawn out? Looking at this carb it has had water in it at one time.. what does the carb bowl bolt look like? I think it has a metered hole in it, Check if you would....

Friiy

I have been wondering about the flow of gas to from the gas tank. I installed a new gas line filter (same as the old one that worked just fine previously) and when I examine the fuel line filter I notice that it is not full of gas. Only a little trickle along the bottom of the clear filter. (the filter is installed with the arrow pointing in the desired direction of flow) Should the filter be filled with gas? It is below the tank when the gas is full. Maybe the little shut off valve below the tank is not working 100%. But still, there is always plenty of fuel in the bowl when I pull it off. Something is odd about all this. I will check that bolt below the bowl. I do not think it has any holes in it.

is there any crud or dirt in the bowl when u take off after it runs and stops? make u replace the fuel line going from the filter to the carb, lve seen it where the fuel line deteriorates and little pieces of rubber start going in the carb and that may be clogging the main jet?

when it stops running l would pull the plug again and check if its wet or dry and check spark at the same time. it could be a sticky valve/loose valve seat causing no compression but its unlikey, just throwing some ideas out there.

The fuel filter not being full of fuel is not a problem, It just has a bubble that will not purge out..


I don't think it is a valve seat problem, when the seat gets loose it doesn't always lay flat in its hole for a restart... I think the valves are---ok.

Try loosening the gas gap when it starts to die, see if it starts to pick up again...

Also---- What type of sound does it give when it starts to die? Does the engine surge? Does it back fire? or does it just stop? Are you useing it under load when it dies? or is it running full speed with no load? or is it Ideling (low speed/ no load) when it dies?

Can you take a video of it as it gets ready to die and poist it on your photo page?


Just throwing some ideas out there...

Good Luck,

Friiy

I appreciate the suggestions on what to check.
I took the carb apart again. I found the "welch plug" that I have heard about on these briggs engines. I probed and poked with the wire from a twist tie in all the holes again. I sprayed carb cleaner into the holes and then blew them out with compressed air.
I was wondering if I should be able to get the carb cleaner to come squirting out that small pair of holes. And if so, where I should squirt or blow in.
I'll put it together tomorrow. If everything goes like it did on Friday, I'll hook it all up, pull the starter cord a few times with the choke on, the fuel will fill the bowl and the motor will spring to life, run for 2 minutes and die suddenly. Then it won't start again no matter what I try. So, we'll see how accurate my prediction is. I will try to take a video. The engine just dies, it it not under load and not idling, just running normal. Last time it stopped, it just stopped like the kill switch had been flipped. The engine has a red "kill switch" on the side. Or at least I think that is what it is. The strange thing about the kill switch is that it has picture of an oil can or a gas can next to the switch. This is a kill switch right? Please tell me its a kill switch, it say "on" and "off" and its red. No idea why they would put a gas can on the switch.
The carb is starting to look really clean.
I'll post a picture of the needle. Can I replace the seat that the needle fits into?