Export thread

This is the 3rd summer using the Troy Built TB 30r rider. This season it starts fine and runs well until it chugs like I'm running out of fuel and then chugs until it stops. I can wait for ten minutes or so and it starts fine and runs well until it starts to chug and stop again. I've changed gas filter, air filter, oil change and new gas and continues to over heat, I think! Any ideas?

Next time it happens loosen the gas cap when it starts chugging. We want to rule out a bad cap that is not venting properly. If it clears up replace the cap.

Rivets said:

Next time it happens loosen the gas cap when it starts chugging. We want to rule out a bad cap that is not venting properly. If it clears up replace the cap.

Click to expand...

Also need to keep in mind if this is a 3-4 year old rider, the fuel cap will be non-vented and will use a vapor recovery system into the low vacuum side of the air intake.

Thank you Rivets and Liengine for your reply. Should the cap be vented? If it uses a vapor recovery system, is there something I could do to remedy this? Thanks guys!

Haliday said:

Thank you Rivets and Liengine for your reply. Should the cap be vented? If it uses a vapor recovery system, is there something I could do to remedy this? Thanks guys!

Click to expand...

If it has the vapor recovery system, the cap won't be vented. Now if that vent plugs up it will have the same effect as a blocked cap vent. You can try to loosen the cap and see if it works. The vapor recovery system will look like a inch diameter black plug on top of the fuel tank with a vent hose connected between it and the air cleaner housing.

Thank you, I'll try that.

Haliday said:

continues to over heat, I think!

Click to expand...

How about removing the metal engine shroud? Maybe clean the block and cooling fins? Heard it's pretty important to do this yearly.

Haliday said:

I've changed gas filter, air filter, oil change and new gas and continues to over heat, I think! Any ideas?

Click to expand...

Ignition coil going out or weak maybe.
Clogged fuel system. Crud in tank and fuel lines passing rubber trash to carb.
Never adjusted the valves.
Never cleaned the cooling fins.

And here is one that I ran into several times during the Spring start up season. The use of Winter fuel. It has a much low boiling point as low as 140F. Heat from the exhaust blowing over the carburetor fuel bowl, fuel lines, and fuel filter. When fuel heats to the boiling point of fuel the system will develop back pressure causing a fuel line vapors lock. I actually seen fuel to be bubbling in the filters at times.

So it can be the cause when the fuel was purchased or when the fuel distributor change from Winter to Summer mix and what the current outside temperature is at the time of the use.

StarTech said:

And here is one that I ran into several times during the Spring start up season. The use of Winter fuel. It has a much low boiling point as low as 140F. Heat from the exhaust blowing over the carburetor fuel bowl, fuel lines, and fuel filter. When fuel heats to the boiling point of fuel the system will develop back pressure causing a fuel line vapors lock. I actually seen fuel to be bubbling in the filters at times.

So it can be the cause when the fuel was purchased or when the fuel distributor change from Winter to Summer mix and what the current outside temperature is at the time of the use.

Click to expand...

I just worked on a 13.5hp Briggs Intek head gasket chunker. Mower set for a couple years. Carb needle hung wide open. When I shut it off, you could hear a percolating sound coming from excess fuel into the cylinder. Filled up the oil sump vent tube with fuel LOL. Fuel was bought a week ago. Hope it was summer blend. ??

Actually sounded like an old percolating coffee pot. That was cool. I was waiting for a fire to break out. Was over 90F that day.

And yes I dumped the oil.

I tried the suggestions regarding vent line and removing the gas cap, unfortunately it didn't make any difference. There must be an answer to this. This is my third season with this tractor and it runs great until maybe 20 minutes or so and it will sputter and eventually shut down. I can wait about 5 minutes or so, turn the key and carry on until it sputters again and stops. I mulch using the mulch plug and have always done so. I sure someone will have the answer. Thanks!

My go to in these situations is an in line spark tester & a can or carb cleaner
I fit the spark tester in a position where I can see it easily then go mow and watch the spark tester
On RER's & ZTR"S I have taken to using a Go-Pro to film the tester/s while I mow
Then as the engine is stopping I look at the tester
If it flashes all the way till the engine stops, that suggest the spark is good & the fuel supply is the problem so the instant it tops I spray some carb cleaner into the carb & see if the engine will fire
If it fires strait off I try to keep it running with more sprays for about 1/2 minute .
If that works I then use a spare tank with enough fuel to run for longer that the mower ran on its own tank connected directly to the carb and gravity feeding
If that works then I move the alternative tank to the fuel pump and try again
If that runs fine then that leaves the tank & the lines from the tank to the fuel pump.
Most of the time it ends up being floating debris in the fuel tank that gets dragged into the outlet and after x minutes it plugs off the outlet .

Now if the plug tester/s do not flash right up untill the engine stops . I check that the fuel solenoid is working and then remove the kill wires off the coils
Problem goes away = wiring problem
Problem unchanged = bad magneto

Haliday said:

I tried the suggestions regarding vent line and removing the gas cap, unfortunately it didn't make any difference. There must be an answer to this. This is my third season with this tractor and it runs great until maybe 20 minutes or so and it will sputter and eventually shut down. I can wait about 5 minutes or so, turn the key and carry on until it sputters again and stops. I mulch using the mulch plug and have always done so. I sure someone will have the answer. Thanks!

Click to expand...

So you've ignored what I wrote to you. All you have done is loosen the fuel cap and complain here. Good luck with it.

slomo said:

So you've ignored what I wrote to you. All you have done is loosen the fuel cap and complain here. Good luck with it.

Click to expand...

What complaint??

Haliday said:

What complaint??

Click to expand...

Exactly.

Okay you are not getting off that easy.

You need to check if you have air, fuel, spark and compression.

Go back and reread what we all offered you.

You need to check for spark with it dies on you. Your ignition coil might be going bad.

I bet you have some junk in your fuel tank like most mowers. Clean it out and install new fuel lines. Nice to add a filter and shut off valve if you have room.

Have you ever adjusted the valves?

slomo said:

Have you ever adjusted the valves?

Click to expand...

I have never adjusted the valves before and don't think I could. You mentioned the ignition coil and I've thought as well. Although it starts ok, could a faulty coil cause the engine to sputter after warming up and running for 20 minutes or so? I've put Seafoam in the tank a couple of times now.
BTW, I do appreciate your input.

Reread Bert’s post #12 and do what he tells you. After preforming this test you will have a lot of info as to how to proceed.

Not trying to pull your strings or be dogmatic but I work this way
I ask you to do some tests
The results of these will make sense to all of the techs & engine savvy people who post here
So when you post the results any one of them can interperate them and either make a diagnosis or require more tests to narrow down the list of potential villians
Now once I have requested the tests I do not usually respond till they are done
Most of us could write a detailed list of at least 20 things that could be the cause of your problems, and in many cases the answer will not be the exact cause as it becomes a cascade A causes B then B causes C and C causes D and D is what you see.