145a runs for a while (20 min) then starts to quit.

02chuck1 · May 9, 2020

I have rebuilt the carb ( I even replaced the little o rings that do not come in the rebuild kit), installed a new fuel pump, new fuel and air filters. Oil level is good.
Starts and runs good for 20-30 min ( i am mowing ) then it will start to surge and the quits. If you catch it and use the
choke it will continue to run (enough) to get back to the shop. I have tried topping off the gas tank and it runs for a bit then acts up again.
I have checked the vent on the fuel cap, it seems ok. I have not touched the ignition system at all since it seems to be a fuel issue.

Ideas?

Thanks
Chuck

beenthere · May 9, 2020

You said you checked the vent.. but have you loosened or removed the fuel cap at that time (moment) the engine surges and starts to quit?

TractorGuy · May 9, 2020

Try a new spark plug. I had a pressure washer doing that once. Stuck a new carb AND coil on it to no avail. Put a new plug in and sll was good.

radios1 · May 9, 2020

did the carb rebuild kit have a stainless steel needle valve?. the plastic one is junk, and will cause problems like this, it swells and sticks in the bore!.. BTDT..

rayikeo2 · May 9, 2020

I had the same problem and it was the vent hole on the gas cap. Loosen the cap so some air can flow around the threads (for test only) or just buy a new cap. When it stalls try to take the cap off immediately, if there is a vacuum the cap will be very hard to remove and you will hear air flow as it inters the tank when you loosen it. Do no keep mowing with this problem as the cap is probably the reason the fuel pump failed. If you use the mower again with a bad cap vent, it will destroy your new fuel pump again. Caps are a lot cheaper than fuel pumps. This problem is not the spark plug.

beenthere · May 9, 2020

02chuck1
Is this a continuation of the earlier problem?
https://www.tractorbynet.com/forums...automatic-surging.html?highlight=#post5641973

See you put in a new PTO clutch to get that working.

But see you have another mower with a different problem.. always something..
https://www.tractorbynet.com/forums...re-lt160-no-start.html?highlight=#post5725141

denchen · May 10, 2020

Some old Briggs and Strattons would do this. I used to loosen the valve tappet clearance, and that seemed to fix it. My theory was the valves would expand more than the engine, and in effect the valves then never closed all the way. When cold, every thing was back to normal until it warmed up again.

02chuck1 · May 10, 2020

beenthere :
Yes I have two mowers acting up. The other one I have had for 8yrs and it has been awesome, just right now it is a PITA for the moment. As noted in that thread I waiting for a friend to get me the correct wiring diagram, so I can check it out.

Yes this a continuation of the previous issues. If you want to attach this to that thread, that's fine, sorry.

I purchased this mower used and didn't check it out good enough. It started good and a quick mow on the guys lawn and it worked decent.
When we got it home and ran it longer is when the issues came up. So rebuilt the carb and it ran well, but the clutch quit during the first mow after the rebuild. Probably didn't run long enough to
act up, which admit-idly is very similar to the first issue. Fixed the clutch and then we came back to the surge and quit problem , it does run a lot longer than when we first started the fight.

rayikeo2
Yes I even went out and ran it with the cap loose to see if there was a issue with the cap. It still ran well for a bit (10-15 min) then you feel it start to surge and it gets worse and dies. If you disengage the blade and a close the choke it will continue to run for a bit, then quit. You sit for a couple minutes it will start with the choke on and you can get back to the shop. I then refill the fuel tank and wait a while and it will start and go through the process again. Also the fuel filter is full of when this happens.

radios1
I do not remember if the rebuild came with a stainless Needle Valve. May have to pull carb to check it out.

TractorGuy
Haven't looked at the plugs, I'll go pull them just check them out.

denchen
I haven't checked the valve clearances, might have to

Thanks the ideas guys
Any more wisdom is always appreciated

Chuck

tomplum · May 11, 2020

These too can have debris in the pick up tube in the fuel tank. It is easy enough to drop a piece of fuel line from the inlet side of the fuel pump and drop it in a fuel container and see if your problem persists.

02chuck1 · May 11, 2020

tomplum said:
These too can have debris in the pick up tube in the fuel tank. It is easy enough to drop a piece of fuel line from the inlet side of the fuel pump and drop it in a fuel container and see if your problem persists.

I have thought that the pick up tube might have a crack or hole and when the fuel level gets down it starts acting up, but getting to it is a real PITA.
Chuck