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Discussion Starter · #1 ·
Hello all. I'm new to the forum and I made a post in the Toro forum but after looking around a bit more I think I should have asked my question here since I don't think it's a brand specific issue. So this is a copy/paste from that post and I'll try to delete the original.

I've got a Toro TimeCutter SS3200 (32") 16HP Zero Turn Lawn Mower that has has me scratching my head lately trying to figure out what is going on. I purchased this mower new in June of 2013. It ran fine the first year, but one day shortly into it's second season it started bellowing smoke out like it had burned a hole in the piston. A quick exam showed a lot of gas in the crankcase. My first thought was that the float must have gotten stuck somehow as it wasn't old enough to think the needle was worn out yet. So I changed the oil and filter and went about my business. A few weeks later it does it again. This time I pull the carb and inspect and clean the float, needle and seat. Long story short it does it again. This time I installed a new float and needle. It does it again as the season comes to an end so I decide to install a cutoff valve in the fuel line between the pump and carb. Well here we are at the start of season 3 and and I check the oil before I start mowing and all is well. About half way through mowing the yard it starts blowing smoke again. I shut it down on the spot and immediately checked the oil. Sure enough, it's full of gas again. So the problem is occurring while it's running and not while it's shut off and parked. I'm pretty sure this much fuel can't be going through the carb while it's running or it would flood the engine and die. My only thought, and it is just a theory since I don't "know", is maybe the vacuum that drives the pump is some how sucking the gas into the crankcase. In doing my research, it appears that the warranty on this mower is still in effect but I'm not sure what's covered by warranty and what's not covered. The closest service center is about 45 miles away, so I'd rather not have to try to haul it all the way there if it's not too expensive and I can fix it myself. So if anyone has ever experienced this or can shed some light on how and why this is happening and how to fix it, I would appreciate it very much.

Thanks
Mike
 

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Mike I'm no expert here but I can think of two possibilities and you've already pretty much covered one, being the carburetor just dumping the fuel.
I don't know, but it seems to me that the only thing between the vacuum side of the pump and the fuel side is a thin neoprene membrane. How about taking the vacuum pulse line loose and examining it, smell it. Do so soon after running it so that if that's the problem it would still have fresh gasoline there.
 

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Discussion Starter · #3 ·
Tom, do you happen to know if they typically sell rebuild kits for these fuel pumps or do you have to buy a whole new pump. I know that similar pumps for outboard motors have rebuild kits for their pumps, but I haven't been able to locate one for this pump. And to be honest, I got a bit of sticker shock when the first place I looked for a replacement pump was Amazon, and they wanted like $56 + 9 shipping. I've since located one for 36 + shipping, but I'm still wondering about a kit.
 

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You can do a little research to answer the question but I do believe they all have about the same operating parameters. If you check ebay I think you can find them for a much better price. When I did, I was able to locate new exact replacements in the $20-$30 range. As far as rebuilding, I believe they're all plastic and ultrasonic welded.

Edit: I said I was no expert and I can prove that. I just looked, some are fastened together and others are welded. The ones which are fastened with screws do have repair kits available. My Briggs 22 is welded and non repairable.
 

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Discussion Starter · #5 · (Edited)
I'm not having any luck finding anything cheaper. I'm surprised at the limited number I have found for sale and nothing cheaper than the 36+shipping. I'm no expert either but I find it hard to believe that a vacuum pump that works on a similar size hp Briggs won't work on my motor. I would think the fuel flow volume would have to be about the same for the same size motors. Providing they have the same size lines and they mount the same it seems like it should work. I haven't verified that mine is bad yet so I've still got that to do any ways. BTW my fuel pump is put together with screws so it can be taken apart.
 

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Hi Mike, Just a note on using gas with ethanol (almost all of the USA pump gas). I've had problems with it damaging the parts in the carb on 2 mowers that are less than 10 years old. Both were B&S. One of the carbs, on a twin, had the plastic parts swell and start to disintegrate to the point it would not start; I needed to purchase a carb. The second was on a single and the needle valve tip dissolved. This caused the problem you described plus it would blow out black smoke when started. I replaced the needle valve. I also added fuel shut-off valves upstream of the carbs and started using Valvtec fuel treatment.

B&S say that they should be okay with the ethanol but I'm not sure they have control over their suppliers.

I just purchased a Simplicity mower with a B&S and the shop said they are using only aviation gas to get away from the ethanol problem. We live near Lake Erie and I'm using Marine Gas which is also ethanol free and cheaper than Aviation. I still test for ethanol but have not found it in the Marine Gas, pump gas has 10% or more in all grades & I've seen 15% once. The test for ethanol is simple; take a water bottle and add water to the second line from the bottom and then fill to the top line with gas. Shake well and let settle. If there is ethanol, the water line on the bottom will be greater than the original because the water will combine with the ethanol and pull it out of the gas. I used a graduated cylinder to calculate the percentages.

If you seem to be down on power after getting the fuel problem solved, check for a blown head gasket. The raw gas in the cylinder can cause them to blow as it did on my single. Some of the B&S singles have a very narrow arrow between the cylinder and valve galley that is easy to blow out.
 

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Discussion Starter · #8 ·
Tom, thanks for the link. That's pretty much what I've been looking at as far as the style of pumps, but not nearly the quantity that your link shows and none of them matched the Toro number. The first one in your link looks exactly like mine so I ordered it. Only a $7 loss if it doesn't work.

Oh, I pulled the pump off my mower and noticed a slight bit of moisture (gas) around the vacuum barb/nipple. I pulled the screws out and took the top off to expose the diaphragm. Sure enough, there were 2 small holes in it about ¼" apart near the outer edge of the diaphragm. It looks like the diaphragm is made of some type of mesh material coated with latex or similar, and the coating was just not applied thick enough in the area where the holes are. I'll try to use the new replacement pump as is but worst case if it's less flow than what mine was, maybe I can swap diaphragms. After getting the pump off and examining the back of it, it's stamped Walbro and the number 13242 / Mexico. I searched for that info but didn't find any matches for sale so thats when I ordered the one from your link. Thanks again for helping me with this.

Mike
 

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Discussion Starter · #9 ·
pwberndt, thanks for the reply. Owning an antique motorcycle and a couple of old outboard motors, I'm acutely aware of the aggravation that ethanol causes. I think I may have even invented a few new (not so nice) words over it. I know what you mean about using avgas and marine gas to avoid the ethanol. I don't know where you live, but most but not all states have some stations that sell ethanol free gas. Here is a link that list most of those stations by state. You can check to see if there's one close to you. If there is, it's a lot cheaper than buying marine or aviation gas.

Ethanol-free gas stations in the U.S. and Canada
 

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Discussion Starter · #10 ·
So I changed the oil and filter, and connected the fuel line up to gravity feed. After letting it run for a few minutes, I took it out into the yard and started to mow with it. Well it didn't take long before it died on me. I waited a few minutes to make sure the carb bowl had time to fill and started it up again. And again it runs long enough to mow 100 feet or so and it dies again. I think/hope it's just a mater of gravity feed no being able to keep the bowl full because if I try to start it right after it dies, it won't start. But if I give it a couple of minutes it starts and runs fine for a couple of minutes. The new pump should be here Tues so I guess I'll have to wait until then to know for sure.
 

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I had similar headache...expert told me it's due to using the pump designed fuel filter in a gravity feed system...Microns...Gravity feed needs less restrictive filter...no paper element inside..Couldn;t prove it...but think it's correct..adding confusion is not all inline filters sold will spec the microns...and some [China] are possibly now course filtering and useable in both systems..but no data states it..and obviously less filtering.
 

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Discussion Starter · #12 ·
Oh! I hadn't even considered the filter might be slowing down the gravity flow. I've got a spare filter made for my motorcycle and it's gravity feed system, I think I'll give that one a try. Thanks for the heads up on that.
 

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:ditto: on what suspicion said.... I also had the similar issue and I kept getting pointed to the same possibility which was the fuel filter. In my special case it ended up being little pieces of rubber that fell off the inside of the gas cap which was disintegrating I guess. Otherwise it was the fuel filter as well that had little pieces in it. Good luck and hope that's the fix! :help:Check back with us and let us know your findings.
 

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Discussion Starter · #14 ·
Installed a different filer and verified the fuel would gravity feed through it at a pretty good flow rate. Motor will start and run non stop if I leave it at idle or just slightly faster. But run the throttle up to anywhere from 1/3 to full throttle and it shuts off in about 1 minute. Give it about 30 seconds and hit the starter and it will start and run again like nothing is wrong, until you try to run it too fast or put a load on by engaging the blade. Then it dies again within a minute. Guess I'll just have to wait for the new pump to arrive and hope that's all it is.
 

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I'm confused...If you verified fuel is flowing at a good rate, by gravity feed...what can a new pump possibly add to it..? Or is your tank "low" and the gravity test was unrelated? Guees I should assume the machine has a low mounted tank..Maybe this can get real technical....with considerations to type of needle and seat used...or maybe simply a misadjusted float?
 

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Discussion Starter · #16 ·
The carb sits about even or slightly above the vertical middle of the tank. When I installed the other filter I held the line roughly even with the bottom of the float bowl. I filled the tank all the way to the top so it would be more likely to gravity feed at least until it gets down to a half tank or so. If there is a way to adjust the float level. I don't know how because it's all plastic. The needle is sort of clipped in to a slot in the float so no adjustment there either. I'm not real familiar with this type carb so I can't tell you why it's not getting enough fuel. I don't know if the carb has some sort of internal resistance that needs the pressure provided by the pump to overcome or what the deal is. I can't even guarantee that the current issue with it dying is from fuel starvation but it sure seems to me like that is the problem based on the symptoms of continuous running at idle, dying at most anything above idle and restart. If I were going to try to operate without a pump full time I would already have pulled the float bowl and examined the flow rate that way. But the pump is on the way so I don't think it's worth the effort at this point.
 

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Discussion Starter · #17 ·
Followup: New fuel pump arrived today. I installed it, replaced the fuel filter with the original, and immediately took the mower out and mowed the yard. It ran well with only one minor problem that turned out to be a case of shooting myself in the foot. Back when I installed a new float and needle, I evidently didn't get the choke linkage put back like it should be. The choke butterfly is operated via 2 linkage rods that both connect to opposite ends of a pivoting arm. Apparently when I disconnected the linkage from the carb end, the pivoting arm was able to rotate 180°. I didn't notice this when I reinstalled the carb. The choke still operated this way but when the choke was off, the butterfly was still partially closed causing the engine to run very rich. Once I corrected that, it ran like new. I'm a very happy camper today.
 
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