it used to run just fine

[rtsideup]

I have a TB-200 self propelled walk behind. Bought it used last year, used it most of mowing season here in Florida. Ran fine first mow of new season. Second attempt of new season this year it won't run. Next time I tried to start it was chugging and didn't want to run more than a couple of seconds. I think I need the valves adjusted. What floors me is how it ran fine all this time with no chugging and now all of a sudden that's all I get from it. I've checked the muffler and it seems fine. No loose head bolts. I was running with a bad air filter last year but I have a brand new one there now. I haven't checked yet but is there a way to make sure you have it at tdc? Is there a timing mark to use? Any help would be appreciated. Lamont

 

[Born2Mow]

Let me guess... you installed some fuel you had sitting around in a can, OR you washed it off with a garden hose. Both look innocent enough, but the engine really doesn't like it.

 

[cityboy]

I have a TB-200 self propelled walk behind. Bought it used last year, used it most of mowing season here in Florida. Ran fine first mow of new season. Second attempt of new season this year it won't run. Next time I tried to start it was chugging and didn't want to run more than a couple of seconds. I think I need the valves adjusted. What floors me is how it ran fine all this time with no chugging and now all of a sudden that's all I get from it. I've checked the muffler and it seems fine. No loose head bolts. I was running with a bad air filter last year but I have a brand new one there now. I haven't checked yet but is there a way to make sure you have it at tdc? Is there a timing mark to use? Any help would be appreciated. Lamont

Have you tried checking if your carburetor is working correctly? It could be dirty.

 

[rtsideup]

Let me guess... you installed some fuel you had sitting around in a can, OR you washed it off with a garden hose. Both look innocent enough, but the engine really doesn't like it.

No nothing like that. First mow of new season it worked fine. Second try and it was doing this(as described earlier). The only change was that I put a brand new air filter on it. It's been chugging and not running ever since. I thought that the valves got out of whack somehow when it acted like that. One question I have is what could change things so badly. Now since I've been playing with valve adjustment it's doing even worse. I've been a fairly decent shade tree mechanic for many years. Rebuilt V-8 car engines from the bare block and built race cars etc. So it's really blowing my mind that I'm having this problem. Right now when I crank it it spins 1 revolution and stops turning and spits out the exhaust. Obviously out of time or valve is closed when it shouldn't be because it's adjusted too loosely. But thanks for the snide remark.

 

[Born2Mow]

>> Things have changed since you worked on V8's. The EPA got involved and redesigned the fuels AND the entire fuel delivery system (the carb, tank, breather, et al).

>> 85% of the time it was the last action you took. Put the old air filter back on. If it runs great, then the new one is far more restrictive and making the mixture "rich", OR it is far less restrictive and the mixture is now too lean.

Time to remove the float bowl and see what kind of presents the EPA has left in there for you.

 

[Scrubcadet10]

yep, could've been the air filter was masking the dirty carburetor by restricting airflow making it run rich, and now it's got a new filter and better airflow and it's leaned out
Almost everything i've ever worked on used to work fine....