# Gas tank discovery.



## sscotsman (Dec 8, 2010)

So I made an interesting observation yesterday!
I think my snowblower has been trying to tell me this for 6 years,
but I didn't finally "get it" until yesterday!

Im using a 1971 Ariens, that I bought 6 years ago..
It has been totally great, flawless in fact, except for one area..the carb.
The tecumseh engine is original, and is showing its age.

It sometimes runs great, and clears the whole driveway with no issues.
other times it wants to stall out, runs rough, etc..

Last winter I finally took the carb apart (which is something I had never done before, so I had been hesitant to try it) and cleaned it..I found a small "stick"..like a mini-pine needle, stuck in one of the needle holes! I installed the new parts from a "carb kit"..put it back together! and it ran great! problem solved! (or so I thought..)

So about a week ago I was using the snowblower, and it started to run badly again!  It finished the driveway, but kept bogging down and running poorly..I tried adjusting the carb needle while it was running, but that didnt seem to help much..I didnt do anything else about it.)

So yesterday, more snow..For some reason, I filled the gas tank to the top, which I had never done before...

I think with the snowblower, and my 1964 Wheel Horse Tractor, I have been subconsciously *not* filling up the tanks with much gas..because gas quality is so bad these days, and I dont want a lot of gas left in the tanks at the end of the season, when I drain them..Of course, logically, keeping only 1/4 to 1/2 of a tank in the snowblower in November or December, the start of the season, makes little sense!  but that has been my thinking, I guess..
So for whatever reason, I dont think I have *ever* had more than half a tank of gas in the snowblower! most of the time it has probably been running on 1/2 to 1/4 tank..perhaps even less at times.

So yesterday, for the first time, I filled up the tank to the very top..
I think its one gallon..

It ran BEAUTIFULLY!!
perfectly smooth, didnt bog down in the heavy EOD snow..it ran like a champ...and finally, the light-bulb went off.

My theory: Perhaps the gas shut-off valve is partially blocked, or something in the fuel line is causing gas to not flow as freely as it should..and the gas is just "gravity fed"..there is no fuel pump, and the gas tank doesnt sit much higher than the carb..
Perhaps a full tank has enough "weight" that it forcefully pushes gas to the carb, much more than a 1/4 full tank would! allowing it to run much better! many of my previous problems could have simply been "gas starvation"! it makes sense...Usually when the engine/carb did start to "act up", it was near the end of a session! it all makes sense now..

So..I learned a new trick! 
keeping the tank full greatly increases performance..

thanks,
Scot


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## Runner50 (Jan 21, 2013)

I've heard keeping the tank full avoids any condensation, so that's been my routine for usage & storage. Don't know whether that played into your problem or not. 
I've also always used Stabil for off season mower storage & never had a problem with start-up in the Spring. I just recently started using Sea Foam for the blower after reading about it here.
My experience with snowblowers is limited, but I'll go with the same routine as the mower.
Do you use any fuel stabilizer?


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## sscotsman (Dec 8, 2010)

Yes, I always use seafoam..
after having a great experience with it, un-sticking a stuck carb float..

For several years, I was leaving gas in for storage..
I have since switched to the "full drain" method..
both are probably fine..

Scot


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## Runner50 (Jan 21, 2013)

Yeah, definitely 2 schools of thought for off season storage. I've always gone with leaving the tank full using Stabil & never had issues in the Spring. Mower always starts right up. I also treat the gas can all season. During usage, checking the oil level & filling the tank before start-up has always been my routine. Seems to work pretty well, so that's what I'll stick with on the blower.


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## HCBPH (Mar 8, 2011)

*Gas*

One thing I've found even more than adding conditioner to the fuel (Seafoam in my case) is using non-oxygenated gas (no alcohol). It causes less problems than anything with alcohol does.

I've tried both draining and not over summer. Fuel keeps the seals wet but draining prevents crap from building up if not run for an extended period of time. It's pretty much whatever you want to do, but put something in the fuel to condition it.


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## Shryp (Jan 1, 2011)

Yea, I have noticed that a full tank is better for a couple reasons. The way the tank ends up sitting on the blower it usually isn't sitting level and it tipped slightly forwards or backwards. Of course the angle will change during use. The old style tanks were flat on the bottom so in essence it took a lot of gas to get a little to the hose. The newer engines all seem to have to tanks above the engine and they have a funnel shape on the bottom to get the last bit out.

Also, if you ever run your engine with the gas cap off you can see that vibration makes the fuel slosh around a lot and in the one I was watching it actually pushed it away from the side where the fuel line connects.


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## twsarch (Dec 16, 2013)

I had similar symptoms a few years ago, for a few years, running rough and hunting. Then the machine told me what the problem was by reeking fuel smell when it was stopped. It was a cracked fuel line. Rough running problem solved for $2. A tip I can offer: get a bit more line then you need if your fuel line runs “thru” your engine and cut one end at an angle so you can feed it thru. Then cut off square for the connection. 

For summer storage, I drain the gas. The first (and last) time I did the carb I replaced the bowel with one that has a drain valve on it so that even gets emptied. Gas does come out of that even after letting it run out of gas when the engine is running. Just my 2 cents, Cheers


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## motorhead64 (Dec 15, 2013)

*steel tanks*

I have had to clean out several many steel tanks over the years in snowblowers and other equipment. If the tank is left full, rust has a much harder time taking hold. If left totally empty, I recommend "fogging" the tank with a light coating of oil. If and when you do get rust, the next stage is scale and pitting. It can be a mess, and you must have an inline filter just under the tank to trap particulates or your carb will act as the filter, and we all know what that means. The advantage of draining is that the gas can be used in your mower and other equipment and you keep rotating your stock. When I drain my gas, I fold a coffee filter and place it in my big orange funnel first...it traps a lot of stuff from your tank and keeps your gas supply clean. MH


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## CO Snow (Dec 8, 2011)

Just another thought - the gas cap may not be venting properly which can decrease fuel flow from the tank. I have a Tecumseh engine and the older gas caps have a circular metal disk inside the cap. That disk often breaks off and eventually stops fuel flow due to lack of venting. That happened to me (and many other owners). Tecumseh redesigned the cap to avoid this problem. A new gas cap solved my problem.


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