B&S 6.5 HP stalls after 1 minute

TrojanEnzo

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B&S 6.5 HP stalls after 1 minute

~10 year old Briggs & Stratton model 123K02-0631-E1 6.5 HP engine (on old Poulan mower chassis) stalls after running about 1 -2 minutes.
I press primer bulb (3 or 4 times) and starts right up and stalls again in 1-2 minutes (over and over again)
So I took off the gas tank to make sure it’s not clogged and the gas line, removed and cleaned spark plug, cleaned air filter and same thing keeps happening.

Need more ideas . . . thank you
 

Scrubcadet10

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have you tried running with the gas cap loose/off?
 

MowLife

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Sounds like you have carb issues. Try to take it apart and clean. Most of the time it won’t cost but a little time and carb cleaner.
 

nbpt100

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If it starts right up after stalling out I would agree it is a carb isssue. Air/fuel. Clean it again and check for air leaks in the intake. Also make sure there is no water in the gas. I have seen that play out this way. Good luck.
 

TrojanEnzo

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WOW, that was fast!
Thank you for replies.
have you tried running with the gas cap loose/off?
yes, didn't make a difference.
I won't be able to get any carb cleaner today (holiday), but I have a can of brake cleaner. I think I'll try that. . . or will that do any damage?
 

nbpt100

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WOW, that was fast!
Thank you for replies.

yes, didn't make a difference.
I won't be able to get any carb cleaner today (holiday), but I have a can of brake cleaner. I think I'll try that. . . or will that do any damage?

Break Cleaner is OK. It is not as aggressive as Carb cleaner but it is easier on rubber and plastic. If you have any tolulene, used as a paint thinner and bru sh cleaner you could put a few drops into the passageways and let it sit for a while. Then clean it out the the brake cleaner. Carb cleaner is often has tolulene in it. Use some compressed air if you have it. Check out the intake gasket and make sure it is not leaking. A little seafoam in the gas at 3 times the suggested use can help if you can get it to stay running. Let it idle for 20 min or mow your lawn. I have seen this smooth out rough running engines with carbs that are hard to clean.

Good luck.
 

Rivets

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Have you checked the float level? Willing to bet that the float seat has swelled and allowing the float needle to close inlet too soon. When you remove the carb, take the bowl off and tip it upside down. The float should be level or slightly down, from the float pin out. My recommendation is to replace the float needle and seat. This is the procedure I use. Maybe this will help.
[FONT=&quot][FONT=&quot]Needle and seat replacement.[/FONT][/FONT]
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[FONT=&quot][FONT=&quot]Remove the carb, and then remove the float bowl. Check the float bowl jet (which is the bowl screw) and make sure the jets both horizontal and vertical are clean and open. Tip the carb upside down and remove the float pin and float with needle attached. Look in the float needle passage and you should see the red float seat at the bottom of the passage. This is where a #5 crotchet hook would come in handy as you need to remove this seat. If you have no hook, but compressed air, you can blow through the fuel inlet and try to pop the seat out. Put your thumb over the passage to prevent the seat from flying who knows where. No air or hook try bending a stiff paper clip to dig the seat out.[/FONT][/FONT]
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[FONT=&quot][FONT=&quot]I would either give the carb a good 24 hour soaking or have it ultrasonically cleaned at this time.[/FONT][/FONT]
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[FONT=&quot][FONT=&quot]With the seat out clean the passage way with carb cleaner. Now you must find a drill bit slightly smaller than the passage way, to be used to press in the new seat. Apply a very, very small amount of a very light lube to the new seat. 3-1 oil or lighter, to help seat it better. Carefully insert the new seat in the passage way with the rings on the seat down toward the carb body. Slowly and carefully force the seat down with the back end of the drill bit. Once it is seated, check to see that it did not flip and the rings are up. Next check to make sure that the float does not have any liquid in it. If it does, replace. If everything looks correct, attach the new needle to the float and install with the float pin centered. It everything is correct, the float should seat level to the carb body, when looking at it upside down. If everything looks good reattach the float bowl, making sure that both the bowl gasket and the nut gasket seal properly. Reinstall on the engine and test unit. Remember to have patience and take your time. Good luck, but I don't think you'll need it.[/FONT][/FONT]
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[FONT=&quot][FONT=&quot]PS: On the side of some Tecumseh carbs you will find a plastic cover. Under this cover will be an idle jet. Remove it and check to see that the jet is open both horizontally and vertically. You should be able to push the old float needle wire through the vertical opening.[/FONT][/FONT]
 

TrojanEnzo

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Thank you guys for all of your help!
I had taken apart the carb and cleaned it thoroughly (per a video I watched) with bread tie wires and brake cleaner etc. I just got the new carb gasket in the mail yesterday, (which I borked while removing it last week) and after putting engine together I was able to cut a large section of the yard without any problems!
Only thing is it doesn’t seem to rev as fast as before.
But I can live with that.
Thanks again.
oops . . gotta try the seafoam today too.
@Rivets: I will probably try your method next.
You guys are the best!
 

Scrubcadet10

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if yours does have one, on top of the carb is spring that should go to a little tab towards the front of the mower, see if you can bend that tab and put more tension on the spring to rev it up more, if needed.
 

TrojanEnzo

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if yours does have one, on top of the carb is spring that should go to a little tab towards the front of the mower, see if you can bend that tab and put more tension on the spring to rev it up more, if needed.

Thank you Scrubcadet! . . That did it!
and thank ALL of yez!
old mower works like new again.
 
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