copemech Posted December 13, 2011 Report Share Posted December 13, 2011 This topic has been raised on a number of occasions over the years, as the fuel tanks seem to expand over time and no longer want to fit the hole they were desighned to go in! Yes, I have had this issue too over the years and it seems something of a difficult issue. I have had to deal with it in various ways over time, as on my '07 bike by elongating the slot at the rear of the tank to accomodate the bolt and trimming the mudguard as well. I estimate a growth of 8mm or so in length, and no real measure of girth, yet things were tight at one point on the sides. I have always related this th the alcohol induced fuels, yet who knows? Well, about three months ago I went back to the 100% avgas mix(no alcohol) if nothing else but the fall climate and the better long term storage properties for the winter months, as I have not been getting out much lately and have just been putting about my little area in the yard and such. Fact is bike has sat for the month due to other obligations, so I go to start it up over the weekend and notice a few things. Firstly, it don't want to start, which is not unusual, as I can tell you even the best fuel goes "off" laying in the bowl of the carb and all the high aeromatics evaporating off through the vents! It does not take long for this to happen. Thankfully a Sherco is simple,and I just remove a few screws for mudguard and airbox to give it a fresh shot of carby cleaner to light things off! Yea, that works! Weather is cold so gotta let it run a bit on the choke and let the stale stuff out, but biggest thing was the FIT, going back! Tank just drops in, mudguard now has a big gap because tank has shrunk, and things are basically back to new proportions! Boggles the mind! Quote Link to comment Share on other sites More sharing options...
tony27 Posted December 13, 2011 Report Share Posted December 13, 2011 Hmm might have to try that, it's the start of summer here now & that could be a way to prove it's not the temp but the fuel change that lead to the tank returning to original size Quote Link to comment Share on other sites More sharing options...
dadof2 Posted December 13, 2011 Report Share Posted December 13, 2011 Its not just Shercos this happens to, gassers used to do it. Thoroughly rinse it inside and out with hot water and a strong alkaline detergent like Deb Janitol Original(5 to 10% mix in water). Then block off the vent hole in the cap and fill it again, squeeze it with the fuel tap open to get about 1/2 litre or a bit more out then close fuel tap. Leave it in a bucket of janitol mix for a couple of weeks. Washing powder wil do if you can't get Janitol. Sometimes this works, sometimes it doesent. Cheers Quote Link to comment Share on other sites More sharing options...
1oldbanjo Posted December 13, 2011 Report Share Posted December 13, 2011 I had the problem on my brand new 2009 Sherco 3.2T in only a few months. I was using premium pump gas and it had ethanol in it and the tank started to grow and push the fender back. I had a month that I could not ride - so I drained out the fuel, washed out the tank with soapy water and put the tank out to dry. I put the tank in an area of the garage that gets very warm when the sun comes out - but not in direct sunlight. In a couple of weeks the tank was back to the normal size. Since then I have gone out of my way to find fuel that is ethanol free and I have not had any problems. I have never used Avgas 100LL as I believe it runs too ruch without rejetting - but I have been able to find Sunoco 96 Octane racing fuel and CountryMark 91+ in Indiana that are both ethanol free. When I know that I will not be riding for a week or so - I turn off the fuel tap and slowly ride the bike around at idle until I run the fuel out of the carb and the engine stops. This gets as much fuel out of the carb as possible without opening a drain plug - and helps when it comes time to start the bike again. Quote Link to comment Share on other sites More sharing options...
ishy Posted December 13, 2011 Report Share Posted December 13, 2011 More and more ethanol free fuel is available in this area for the boat motors, it's also better for the chain saw and garden equipment. We had the same problem and the change of fuel cured it, who knows if the grain price goes up enough they may stop using it for fuel and farming subsidy. Quote Link to comment Share on other sites More sharing options...
copemech Posted December 14, 2011 Author Report Share Posted December 14, 2011 I know full well not to leave things sit too long even with decent fuel in the bowl, yet that seldom happens here. Other than that I have never had a problem, usually a 2 kick operation or less. In the 2T, the straight Avgas seeme to do OK, but not in hot weather, as it seems to vaporlock on hot restarts. Although it does seem to keep well in a sealed container, and better than even non alcohol car gas. But getting clean car gas here is next to impossible yet it seems, unless you want to go to Oklahoma for a small can! Seems you gotta be careful with the race fuels even, as a recent read suggested that even VP was running a 5% blend in most, yet one of their fuels! Back to the start, I was just surprised the damn thing shrunk! Quote Link to comment Share on other sites More sharing options...
dazzagreener Posted December 16, 2011 Report Share Posted December 16, 2011 Can anyone tell me a quick step by step to get my tank to shrink back to its original shape. cheers Darren Quote Link to comment Share on other sites More sharing options...
zippy Posted December 16, 2011 Report Share Posted December 16, 2011 step 1. buy new tank well that was quick sorry could not resist, since I have had a or two Quote Link to comment Share on other sites More sharing options...
copemech Posted December 17, 2011 Author Report Share Posted December 17, 2011 step 1. buy new tank well that was quick sorry could not resist, since I have had a or two Nice try Zipper! Point I was making here is I just put non-alcohol laced fuel in and left it alone! It shrunk! Quote Link to comment Share on other sites More sharing options...
dazzagreener Posted December 17, 2011 Report Share Posted December 17, 2011 Nice try Zipper! Point I was making here is I just put non-alcohol laced fuel in and left it alone! It shrunk! iv also herd leaving it in the sun empty helps as well but not sure has anyone tried this???? does anyone in the UK know were i can non alcohol fuel from cheers Quote Link to comment Share on other sites More sharing options...
copemech Posted December 18, 2011 Author Report Share Posted December 18, 2011 iv also herd leaving it in the sun empty helps as well but not sure has anyone tried this???? does anyone in the UK know were i can non alcohol fuel from cheers There is probably some type of racing fuel dealer in your area. Mind you being race gas does not make it alcohol free, as much race gas is "oxigenated" meaning it contains alcohol for its anti knock properties. You must research this. It does stand to reason that emptying the tank and letting it outgas would work. Just how long it takes I am unsure. A bit of heat such as laying in the sun, or a hairdrier may help, but not to get things too hot! Quote Link to comment Share on other sites More sharing options...
tony27 Posted August 3, 2012 Report Share Posted August 3, 2012 Given up on trying to shrink mine, wont fit in the frame without bending upwards & is jammed against the head stay etc. Would need to cut about 15mm off the guard to get it hooked under the frame properly & thats not going to happen Have ordered a new tank & the correct graphics to go with the new rear guard I already have hanging up in the garage, should see it in the next week or so May try soaking the old tank at a later date to see if more time has any effect Quote Link to comment Share on other sites More sharing options...
copemech Posted August 5, 2012 Author Report Share Posted August 5, 2012 Given up on trying to shrink mine, wont fit in the frame without bending upwards & is jammed against the head stay etc. Would need to cut about 15mm off the guard to get it hooked under the frame properly & thats not going to happen Have ordered a new tank & the correct graphics to go with the new rear guard I already have hanging up in the garage, should see it in the next week or so May try soaking the old tank at a later date to see if more time has any effect And what fuel has been init? Quote Link to comment Share on other sites More sharing options...
tony27 Posted August 5, 2012 Report Share Posted August 5, 2012 Normal 98 octane pump gas, getting avgas is a major pain nowadays with the aeroclub not operating constant hours I tried flushing the tank out a couple of times with degreaser then detergent & leaving minus the cap in the sun during the day & near the fire at night I think my tank may have grown more than yours, the guard gets nowhere near the frame & has to be forced into the frame. Has happened rather quickly Quote Link to comment Share on other sites More sharing options...
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