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Engine won't start

#1

M

Martini

Craftsman Model: 247.37031

Briggs and Stratton Model: 126M02-6863-F1

I was mowing and the engine was stalled the grass was way too long. It wouldn't restart. I was using last years gasoline, so I was pretty sure that was the issue since I've had that issue before. I emptied the tank and put in new gas. Won't start.

I tried putting a little gas in the carb and still no luck. Then more and more gas.

It spurts gas out of the carb when I try to start it (air cleaner off). I tried with holding the choke plate open with a screw driver and that didn't work either. It's been a half hour resting, just tried again. Nothing.

Any ideas what to try next?


#2

R

Rivets

Might be flooded. Try removing the plug and pulling it over to get all gas out of the cylinder. Install plug and try restarting. If that doesn’t work, time to clean and rebuild carb if it sat with old fuel.


#3

M

Martini

Did the above. Carburetor was clean as a whistle. No joy. :(

Do I have have to add fuel to the carb before trying to start?


#4

Scrubcadet10

Scrubcadet10

Did you make sure the holes in the bowl nut were clear of debris?


#5

R

Rivets

Time to clean and rebuild the carb. Part number 398188. Here is the procedure I use.
[FONT=&quot][FONT=&quot]Needle and seat replacement.[/FONT][/FONT]
[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]
[FONT=&quot][FONT=&quot][/FONT]
[/FONT]

[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]
[FONT=&quot][FONT=&quot][/FONT]
[/FONT]

[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]
[FONT=&quot][FONT=&quot][/FONT]
[/FONT]

[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]


#6

M

Martini

Time to clean and rebuild the carb.
As I said in my last post:

"Did the above. Carburetor was clean as a whistle. No joy. :("


Out of desperation. Got a new carb. Still no hint of starting.
Have spark. Carb fills with gas.

No idea what to do next other than have you folks look at the linkage and if I did anything stupid and see if there's a fix someone can recommend:

https://youtu.be/sgQ_uYSamdI


#7

upupandaway

upupandaway

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It spurts gas out of the carb when I try to start it ....

Any ideas what to try next?

With puddle of gas in the carb, 99% it is not because of a dirty carb. Check the gap between the tappet and the valve. If the gap is fine .004"???(confirm this spec with your motor), take the cylinder head off and confirm there is no dirt holding the intake valve open.


#8

R

Rivets

It’s an L-head engine so I doubt the valves are off. I know you cleaned the carb, but did you make sure you float was set as I described in my procedure? Second this is an auto choke system, have you check to see if you have set the choke system properly and the choke is fully closed during starting? There is a small spring which pulls the choke closed when cold and then the airvane will open the choke once it starts. Have you checked for spark?


#9

M

Martini

Rivets, it again appears you aren't paying attention to my posts. I not only cleaned the carb, I replaced it with a new one.

Did you watch the video I linked to? Yes, it's an auto choke system. It is fully closed as shown in the video. Once again, I checked for spark and there was spark.

I am going to replace the plug tomorrow in case it is weak. I'm pulling my hair out over this.


#10

R

Rivets

Sorry, but at my age I don’t do videos. Hope someone else can help you out, because I am at a lose on a next step.


#11

B

bertsmobile1

As your mower stalled out there is a slight chance that the flywheel has spun onn the shaft & put the timing out.
Get some spray carb cleaner or starting fluid.
Remove the spark plug and give the engine a SHORT shot down the plug hole.
Fit a NEW plug and give it a pull or two
Engine does not go bang, take the flywheel retainer off & check the flywheel key

Engine goes bang = valves are closed & the ignition timing may be OK.
Repeat but squirt down the carb throat.
Engine does not go bang = valve problem
Engine starts and runs till the fuel is burned ≈ 5 seconds = ignition & valve timing is good.
Repeat but continue to give it SHORT shots down the carb.
If you can keep it running like this for around a minute = fuel problem


let us know how you go.


#12

M

Martini

I put in a new plug. Didn't start. I gave it a shot of starter fluid in spark plug hole and it went "bang", but just for a second.

Tried down the carb and couldn't get a bang.

Gonna repeat again and see what happens.


#13

M

Martini

As your mower stalled out there is a slight chance that the flywheel has spun onn the shaft & put the timing out.
Mystery solved. I'll post back after I replace the key and attempt to start it.


#14

M

Martini

Started on the first tug. :) Thanks for all the help, guys.


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