Briggs Intek twin 407777-0174-e1

[Curleyg]

Hey Guys and Girls. I've been working on this motor on and off for 4/5 years. Replaced the mower when it started acting up and break this out and try something else when I feel like it.
The mower starts, runs, and cuts fine for 60 to 90 mins then starts spitting sputtering then quits. Let it sit for a couple of hours and I can get another hour out of it. Here's what I've tried.
Replaced
All fuel lines, gas cap, filter, and pump. Heads with valves and new push rods. Coils, plugs and wires.
I have a friend who bought one of these lt2000's the same time I did. It did the same thing. He gave up and junked it. I have taken it to mower repair shops who said they couldn't duplicate it. Because they're not going to cut with it for an hour or more. I can burn an entire tank of gas with no issue as long as there's no load. Any suggestions will be appreciated.
Sorry the post is soooo long.

 

[bertsmobile1]

drain the fuel tank let it dry out then blow it clean.
At the same time replace the fuel lines from the tank to the carb.
There is loose & floating debris in your tank & possibly the fuel lines that plugs the outlet when sucking fuel fast.

 

[Curleyg]

I have cleaned the tank and as stated earlier replaced all fuel lines.

 

[Curleyg]

And always starts acting up just after an hour regardless of the amount of fuel in the tank.

 

[Curleyg]

All that said, I will try cleaning it again.
Thanks

 

[keakar]

sounds like you have space aliens in there and they are causing issues ?

man this is a strange one that is for sure but if itsnot losing compression when it happens then i may have the solution for you.

i had a mower doing this once and it turned out to be the shut of solenoid would gradually get weak and eventually close even with power still being applied. but in my case it didnt matter if it was cutting or not, it would just spit sputter and die after about an hour for no reason at all.

those carbs are much cheaper now ($25) so just replace it and you get a new solenoid you would have to pay $12 for any way

look here https://www.ebay.com/itm/Carb-Replace-Briggs-Stratton-20HP-25HP-Intek-V-Twin-Engine-Carb-791230-796258/303144711077?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

 

[Curleyg]

I will give that a shot. Currently out of stock, but I put it on my watch list. Side note: I went to ereplacement parts, they wanted $200 just for the solenoid.

 

[ILENGINE]

Something to keep in mind also is on some of the craftsman mowers which would also include some of the poulan mowers, there was an issue with the heat shield above the exhaust pipes would direct heat directly on the carb causing it to boil the fuel in the carb. So if it quits reach down and feel the carb bowl and see how hot it is. The ones that I come across you couldn't hold your hand on the fuel bowl.

 

[StarTech]

Or even in the fuel filter. Note: Gasoline can boil as low 140F depending on its formulation.

 

[Curleyg]

Ilengine, thanks for the tip. I'll certainly give that a look also.