Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

RemmyZero · Jul 27, 2013

Hi guys, i'm new to the forum and I can't solve my issue at all. I acquired a used Troy-Bilt model 34073 mower from my coworker with a B&S 8.5hp engine model 692684. It was in storage for several years but when I got it the mower started right up. After a few weeks it would die after 20 minutes and was hard to start. Also it would only run if I left the choke on.

Today I finally did some googling and took the carburetor apart and cleaned everything and blew out all the passages. The mower started right up after and ran for maybe 3-5 minutes then died. It will only restart once I let it sit for an hour, and I have to drain the carburetor bowl so it seems to be a flooding issue. On top of that when I pull the air filter off I see a pool of gas in the plastic housing for the filter. Everything i've read points to flooding or blockage. I checked the float and the needle valve and it floats in a bowl of gas and the valve seems ok. No gum or deposits. The fuel line seems to be ok, as the carb bowl is always full when it stops running (I empty the bowl each time to check).

I've done every recommendation I can find and nothing has worked. Unfortunately I stripped the slots on the main jet so I could not remove it, although it appears to be debris free as air and carb cleaner run right through it when I cleaned it.

Any ideas? My last thoughts are to drill out the jet and get a new one and a new float but I'd like to really know what the issue is. Maybe it's time to shoot the fuel line to be sure? (although since it's flooding I can't see how this would help)...

Thanks in advance!
Bob

Carscw · Jul 27, 2013

If you let it sit for a hour and don't drain the bowl will it start.

(( racing is the only sport that you need two balls ))

RemmyZero · Jul 27, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

Carscw said:
If you let it sit for a hour and don't drain the bowl will it start.

(( racing is the only sport that you need two balls ))

To be honest I haven't really tried that today but I don't think it will start without assistance because every time i've taken it out of the basement and tried to start it the thing won't even make any sound like it's combusting. No smoke, no nothing. It does not, however, squirt gas out of the muffler. I also realize I forgot to mention that I also think it's flooding because I had smelt gas for the last week in my house. What would that indicate if it did start though? Also, I just restarted it (had the carb apart) and if you put it in choke it dies so it doesn't seem like what i've read online about blockage.

I also double checked the fuel line and it's good. Gas flows freely.

RemmyZero · Jul 31, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

Also, i'm wondering if improper torquing of the spark plug would cause gas not to get drawn from the carburetor into the combustion chamber (which would explain why it's sitting in the low point of the filter housing). Perhaps I need to check the torque on the plug? Any thoughts? This is making less and less sense to me since I can't find a smoking gun ha ha!

Thanks again!
Bob

troybiltbob · Aug 2, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

If the machine is flooding check the float to see if it returns to the top os the carb by pushing it down with your finger and releasing it if it sticks the float is out of alignment and jamming against the side of the carb. If it isn't that check the leval of the float you can bend it so it sits closer to the bottom of the bowl. I had a problem with no gas getting to my carb and it was the rubber hose had deteriorated and a piece was blocking the inlet on the carb but yours is a totally different problem. Hope this helps. Bob

RemmyZero · Aug 3, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

troybiltbob said:
If the machine is flooding check the float to see if it returns to the top os the carb by pushing it down with your finger and releasing it if it sticks the float is out of alignment and jamming against the side of the carb. If it isn't that check the leval of the float you can bend it so it sits closer to the bottom of the bowl. I had a problem with no gas getting to my carb and it was the rubber hose had deteriorated and a piece was blocking the inlet on the carb but yours is a totally different problem. Hope this helps. Bob

Hi Bob, thanks for the suggestions! Well i've put the float in a bowl of gasoline to make sure it floats and that was ok, although I think I see what youre suggesting but I can't get to the float with the bowl on to see if it's an issue. Also since it's plastic I don't think I can bend it at all. Perhaps you have a different style float? The one I have just looks like a plastic denture, for lack of a better description. I'll check the alignment with the bowl off though.

troybiltbob · Aug 3, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

Making everything cheaper theese days. If it is the float check to see if you can buy a new one. You could apply some heat from a hair dyrer and try to bend it, but make sure you can get a new one just in case. Also see if the needle valve goes up and down freely maybe some debris got stuck in there. Bob

RemmyZero · Aug 3, 2013

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

Well I ended up finding out what the issue was. Shame on me for not checking earlier. The crankcase was FULL of gasoline and oil. I suspect it would run when cold until everything expanded and since the volume was so great the engine would just hydraulic lock. Oddly enough i'm not sure how this happened and how so much of it got into the crankcase, or why this caused so much gas to go into the filter housing. Regardless, I drained the oil, refilled the engine and changed the plug and she fired right up. I adjusted the idle and mowed my lawn like a happy man.

I'm going to watch and see if this happens again but either way i'm installing a cutoff on the fuel line. The only time I suspect this could have happened was over a month ago when I transported the mower to my mother's house to cut her lawn. Perhaps being at an angle on the ramp allowed it to happen but I would think the problem would have manifested sooner. I also found oil/gas on the floor in my basement where I store the mower so it appears it started coming out the crankshaft seal. Either way i'll keep my eye on it. Now the only issue is that it won't start in choke and backfires when I shut it off but at least it's running and I can work on the rest at my leisure.

Thanks for the help!
Bob

Cfs · Apr 7, 2018

Re: Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

RemmyZero said:
Hi guys, i'm new to the forum and I can't solve my issue at all. I acquired a used Troy-Bilt model 34073 mower from my coworker with a B&S 8.5hp engine model 692684. It was in storage for several years but when I got it the mower started right up. After a few weeks it would die after 20 minutes and was hard to start. Also it would only run if I left the choke on.

Today I finally did some googling and took the carburetor apart and cleaned everything and blew out all the passages. The mower started right up after and ran for maybe 3-5 minutes then died. It will only restart once I let it sit for an hour, and I have to drain the carburetor bowl so it seems to be a flooding issue. On top of that when I pull the air filter off I see a pool of gas in the plastic housing for the filter. Everything i've read points to flooding or blockage. I checked the float and the needle valve and it floats in a bowl of gas and the valve seems ok. No gum or deposits. The fuel line seems to be ok, as the carb bowl is always full when it stops running (I empty the bowl each time to check).

I've done every recommendation I can find and nothing has worked. Unfortunately I stripped the slots on the main jet so I could not remove it, although it appears to be debris free as air and carb cleaner run right through it when I cleaned it.

Any ideas? My last thoughts are to drill out the jet and get a new one and a new float but I'd like to really know what the issue is. Maybe it's time to shoot the fuel line to be sure? (although since it's flooding I can't see how this would help)...

Thanks in advance!
Bob

Bob,. Just curious...did you ever get this fixed? I know this post is 5 yrs old. Briggs had some problems with the Carb inlet seats on this engines, I fixed one for a friend and it took care if it.

Cfs

Troy-Bilt 34073 - 8.5hp B&S engine - won't start - filter housing filled with gas

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