Chraftsman LT-1000 B&S Intek 18 HP OHV won't stay running

[Bobalu]

As usual, my first day of lawn care for the season is a bust. I had no problem starting up and everything ran fine for about ten minutes. Just when I went to stop to empty the totes, I disengaged the blades and she started to die, as if running out of gas. A few seconds later the engine quit. It would turn over but not fire again.

The gas was fresh and had fuel additive in it. I had good fuel flow to the carb. The vent in the tank cap was clean. The inline fuel filter is new. The spark plug is new. The air filters are clean, though not new. I checked the kill switch under the seat with my meter and it checked good. I also plugged and unplugged the connection to the tiny solenoid in the carb bowl and it clicked on and off as it should. That solenoid does get a bit hot. The float in the carb seems to be working and you can hear a click when you raise and lower it.

I did get it to fire once during the many times I tested it. It was right after checking the carb float. I actually pulled the pin on the float hinge and let the needle valve drop down for inspection. That was the only time it fired and it never got running to full RPM. Just ran slow like starving for gas then died. Subsequent attempts to start wouldn't even fire.

 

[Rivets]

Got a couple of things you can try. One, try to spray some carb cleaner into the carb air horn and see if the engine will fire. If it does you know if you have a fuel problem. If it doesn't you'll have to check for spark. If it fires I think you have a stuck float needle valve or the needle is not installed correctly. Make sure that when you check the float tip the carb upside down and check to see if the valve moves as you raise and lower the float. Second make sure that the fuel pump is working properly. Take the fuel line off the carb and turn the engine over and see if you are getting a good flow. I don't feel this is the problem, but a simple check.

 

[Bobalu]

We used some small engine starter fluid to spray down the breather tube and it did fire, so I guess that eliminates the spark issue. Still can't get the engine to run on just the gas coming to the carb.

 

[Rivets]

Did you test the fuel pump to make sure the fuel is getting to the carb? If you know you have fuel getting to the carb then you will have to rebuild the carb to make sure that all passages are clear. If you don't know how to do this, take it to a good service tech and have them dip clean it and put in a rebuild kit.

 

[Bobalu]

I'm not sure this has a fuel pump. Looks like a gravity flow to me. Nothing between the tank and carb except the fuel filter. Would it be internal?

I found a carb rebuild kit on-line and will order. I'm not an engine repair guy, but I am a machinery repair mechanic by trade. I should be able to muddle through, but I have the back up of my son-in-law who does this type of work as a hobby on cars.

 

[Rivets]

Go online and you should be able to find a Briggs manual to help. Got to get to work, but if I get time I'll send you a link.

 

[SONOFADOCKER]

Another thing to look at is the blade disengage cable . Might be stretched and won't start thinking the blades are engaged ?

 

[Bobalu]

Another thing to look at is the blade disengage cable . Might be stretched and won't start thinking the blades are engaged ?

I'll check this out. I recall on a few occasions leaving the blades engaged and trying to restart. The engine wouldn't turn over at all. In this case, however, we can get the engine to turn over easily, but not fire....or fire only when filling carb breather tube with starter fluid. Would that still occur with a stretched cable?

I'm really starting to think this might be a valve issue. While running it (for whatever short time) on starter fluid, it backfired a lot. Perhaps the exhaust valve isn't seating due to a bent rod. I had this same engine repaired about five years ago for a bent rod. There was also an incident late last season when it suddenly backfired and the engine became quite loud, like I had just blown the baffles out of the muffler. It has run loud like this ever since. Could this be a clue?

 

[Rivets]

be careful using starting fluid. Starting fluid (either) is very dry, can and will dry out the cylinder which will lead to major problems later. I recommend carb cleaner. It has oil in it and will not dry out parts. A compression test will help you determine if you have a bent rod. A cylinder leakage test is even better it you have access to the tester.

 

[Bobalu]

The son-in-law had a day off, so he pulled the head. As we suspected, the intake valve rod is bent and the rocker arm is off to the side. I'll order up the parts and get this fixed before the snow falls again, I hope.