QL 1000 shutting down when hot
 

The Quietline 1000 runs fine when I first start it up. After mowing for 30 to 45 minutes, depending on how hot it is outside, it will shut down. If I try to start it back up, it will not start. If I wait 5 minutes, it will start.

It seemed like it would be the coil, so I replaced it. Still the same. Three years ago, when I first got it, I had replaced the spark plug, points, and condenser, even though it was running fine.

Today, I swapped out the condenser with the old one. Same problem. I'm going to pick up a new spark plug, even though the current one looks fine and has been cleaned. At this point, I'm just trying the process of elimination, just to rule out certain componets.

The air filter has been checked and cleaned. The fuel filter is brand new, and I've disconnected the fuel line just to make sure fuel is flowing properly, and it seems to be. The battery connections and ground is tight. The first couple times it happened, I drained the fuel and replaced with new. Same problem. I'm running out of things to try. It has happened over a dozen times now.

I don't think it is any problem with not getting fuel, because it only happens after it is hot, but when it happens, it does feel like you just ran out of gas. Sometimes, when it first starts to stall out, if I back the throttle off some, it will keep running for a few more minutes, but eventually it will shut down.

Any thoughts, ideas, or suggestions would be greatly appreciated.

JT

Sounds like the "Exhaust Valve" sticks open when it gets hot. When it cools down, then it will close. Try checking compression right after it quits.

Have you tried pulling out choke when it happens to see if it comes back to life? May be something floating around in tank and getting down to Petcock area. I know you said you don't think it's fuel but just making sure. Roland's suggestion of exhaust valve sticking may be the ticket, but you'll have to be fast on the compression check

My 122 did the exact same thing. I began researching and found that using regular engine oil will cause the exhaust valve stem to get gummed up and cause it to hang open. I removed both valves and clean them and the guides and started using Low Ash oil. Hasn't happened since, and that was 5 years ago.
Also, my cousins Cub was doing the same thing. He carries a hammer with him when he mows. When it starts to stick open, he hits the head where the exhaust valve is and it knocks it back down. Not the best thing to do, but it'll get you by until you fix it right.

I read the debate on Low Asj vs conventional and synthetic oil, but since my 122 did that and I began using Low Ash, that's what I'm sticking with.

I'd agree with Roland, sounds like the exhaust valve. did you ever actually check for spark when it dies? I

:bigeyes::bigeyes:

:bash2:

I had two 14HPs (149 and a "148") that would do that.
It happened when I was plowing snow with a 54" blade.

It was so frequent, I was able to recognize that it was about to happen,,,,, :bigeyes: I could stop for about 30 seconds, the engine would cool, and off I went again.

I reamed the valve guide for the exhaust valve, and the problem was solved.

Never said it was the best thing to do. Just saying it'll get you out of a bind quickly. I personally wouldn't do it to mine.....

Thanks for the replies, folks.

I have not checked the compression. I use Pennzoil 30w, and have been since I got the tractor 3.5 years ago.

I was thinking it was going to be something electrical, but it is sounding like maybe it could be that exhaust valve. I wonder if adding something like Marvel's or another additive would clean things out?

When it first started happening, I think I did pull the choke out, and it seemed to keep running a little longer, but I had somewhat ruled out the fuel issue because it always happens after it is fully hot, never when cold, or within the first half hour.

Dang, I just put $$ into a new clutch. It would suck if I have to have the engine torn down now. This tractor is really letting me down this year, and I'm not very happy about it. I even had a flat front tire this year. Not a good year for the Cub.

JT

Man just gotta remember these are old machines and issues do come up once in awhile. Dosnt take much to fix the valve problem most of the time pulling the valve and cleaning it up does the trick. Just a evening with some tools good luck man