wont stop dying!

[Bwgad96]

I have an old craftsman lawn mower with a 15.5 hp briggs and stratton on it. it will run fine for about 2-3 minites then start to make some nasty coughing noises and it will do this for about a minute or so be fore it finally does out. ive cleaned the carb, and completly tore it down and soaked it overnight then rinsed out with water and let dry for about an hour in direct sunlight. u am thinking it is the coil gettin hot, because after it dies out it wont start till it cools down. any ideas/comments? thanks

 

[6string]

I have a Poulan with a 15.5 that acts similar, crank it up and it runs fine for about 10 min. and then starts smothering down and cutting out. It has never died on me but today I had a hard time starting it, it would backfire and run a little and then finally started but ran rough. I cleaned the carb. last summer(Nikki) with no good results. I suspect the coil may be overheating but have not priced a new one. I'm sure they're not cheap. I removed the engine cowling and cleaned out all the dead grass, a mouse nest, mouse skull(wonder what killed him?:laughing. I also checked the intake manifold gasket at the block for damage. I had one mower that acted like this one and the intake manifold gasket had torn. Does yours have the solenoid on the bottom of the carburetor bowl? I am suspecting that may be the problem with mine. I have done the valve adjustment several times and it has made no difference. Have you removed the gas cap when it is running rough to see if it is venting ?

 

[Bwgad96]

yes sir I have done quite a few of these things.ive tried the gas cap with no luck, and mine also does have the sylinoid at the bottom of the carb( walbro) which is functioning properly so when i turn the key it pops open. I looked ot up and a new coil is about 35.00 bucks. I think im going to go to my neighbors house who has about 5 of these and buy one off a parts machine.

 

[Bwgad96]

I am really staring to think my problem is that silly sylinoid closing up on me!!

 

[6string]

I have read of some people replacing the solenoid with a brass plug and gasket. I don't know if you have to ground the wire to the solenoid or leave it open. I would like to try that on mine but I have too many irons in the fire right now. I prefer a Walbro over the Nikki carburetor.

 

[Bwgad96]

Thats a great idea where could i get one of those brass plugs?

 

[Jim Thompson]

Just remove the solenoid, clip the plunger and reinstall. You may have to experiment shutting the engine off at different throttle settings to prevent it from backfiring.

Jim

 

[Bwgad96]

Ok, so that issue is fixed!! But sadly it is still doing this sputtering. So im pretty sure my issue now is the coil.that is my best guess any input?

 

[Bwgad96]

im still up in the air about ordering the coil, any other imput?

 

[Bwgad96]

New coil came today, an theres no diffrence. Runs beutiful for 10 minites tuen sputters and dies. im stumped!!