# Ethenol gas & small engines



## G-Mann (Dec 29, 2007)

After 5 years of running my Stihl FS45 trimmer and BG55 blower, both started running bad. Took the carbs apart and found that the diaphrams on both were quite hard and brittle. For a few dollars more, I replaced the carbs on both units. They now run great!

Could it be that ethenol gas at 15% be the cause of such a failure?


----------



## David Reynolds (Nov 20, 2018)

That is most likely what caused it. If you are getting five years out of these carbs you are doing something right. Ethanol and rubber and such type gaskets don't mix very well. To my knowledge there is not much you can do about it except replace the diaphragms or whole carbs. Go online and look up "ethanol and small engines". Read it and weep. Also, if you find anything that will help save problems with ethanol, let me know. The best thing anyone can do is use Sta-bil in their gas and gas and oil mixtures.


----------



## finaprint (Jan 29, 2006)

Yes, the ethanol makes the rubber flapper valves get hard to not be nearly as flexible, they need to be to positively meter fuel correctly and why the idle goes to crap and then they begin to die easy and hard start. If your carb can be equipped with the newer mylar type valves they last longer under ethanol use. 

When done always drain the fuel and then light the motor up until the diaphragm section pumps out all fuel to run out of gas, that will make the valves last longer. If you leave it full of fuel then sometimes it will phase separate and then the water turns into acid to eat parts alive. 

Stabil works but if you tip the bottle a bit too much that can bring another set of problems too. Too much overwhelms the fuel ability to vaporize easily then hard starting issues.


----------



## Hobby Dude (Aug 7, 2019)

Ethenol is the bane of all engines, its funny we pull fresh oil from the ground, refine and sell it? Then we buy oil from other places, refine it then ruin it with ethanol any engine's worst enemy. I have to 250 cc scrambler 2 stroke bikes, and I swear since the late 80's I have been cleaning fuel systems until my hands burn all the time an my liver is swollen up. I wish a rapid end to ethanol fuels, and returning back to the good stuff......


----------



## finaprint (Jan 29, 2006)

I used to print the financial statements of several ethanol companies (my moniker 'finaprint') and the government subsidy is still the only reason ethanol even exists. Ethanol still costs about $6+ at the producer to make but the government pays for enough of it to lower the final cost to customer of below the price of straight gasoline and then why they mix locally at a percentage to make more profit from the fuel and why often the 'legal' % amount stated on the government 'regulations' is lower than what you actually get in reality. Here in Texas they test for too high ethanol amount as the fuel gets it put in at the delivery point; premixing it causes way too much trouble with the fuel in transit. You can't pipe in ethanol (ask Exxon what happened when they tried, millions in pipe damage), it only can be trucked in stainless tankers. Mixed local they can tilt it to over 10% on a legal amount of 10% and often up to 20% and the car dealers test to invalidate car warranties as soon as they find the too high percentage, you then pay for repairs on brand new cars. At the new official number of 15% you can expect it to be as high as 25% in reality, there is no real quality checking for % there at all and a national scam. The higher % then makes more profit for the company as the higher you tilt the % the less gas mileage you get. Why so many people are chasing cars that seem to get worse and highly varied gas mileage per tank, the variability of the fuel you get day to day can change your numbers 2 miles a gallon easily. Many take the new cars back complaining but there is nothing wrong with the car at all. 

If the government simply dropped the subsidies on ethanol the companies making it would be out of business overnight, they cannot sell it at all at the real world price it takes to make it and all the producing companies call that out somewhere in their financial statements. So, you get taxed for it and get to overpay again at the pump when you use it. Cornflakes NEVER made that kind of a profit, but because the whole idea is set up to be a scam.


----------



## finaprint (Jan 29, 2006)

Have you ever spilled gasoline while filling a mower up on a 100 degree day? The ethanol content pulls the rest of the fuel with it at an evaporation rate easily twice as fast as gasoline does by itself. I've watched a quarter pint spill evap to be gone in less than 30 seconds before. That super fast evap rate is what does much of the damage, older school carbed engines with venting right on the carbs to atmosphere can have fully filled fuel bowls dry in only 2 days sometimes. I have a '77 Honda CB550F that will tend to stick the carb needles all 4 closed with often less than one week of sitting here in Texas. I developed a process of gently blowing the needles back open with an air hose after getting tired of yanking carbs apart over and over simply to tap the needles back loose with a finger tip to make them work right again. The superfast evap rate is why the smaller carb passages like idle feeds tend to clog fast too. 

On 2 strokes, fits with engine life as ethanol kills much of the fuels' ability to bind with the oil all 2 strokes have mixed with it. Then you get shorter engine life when that leads to less oiled main bearings which are commonly ball or roller or needle type. 

Water in fuel? I wash parts in gasoline, carefully and always outside of course. I don't smoke either. Here in Texas, cleaning parts will typically cloud the fuel to phase separate and water forms in it in five minutes on a warm high humidity day. Or, faster than spit. One good quality to it though, you can wash the cleaned parts off with a water hose and the typical oily residue is no longer there like straight gasoline used to leave, the ethanol component causes the fuel to rinse away 100%. You MUST provide for immediate rusting though, the parts will be so bone dry they will try to rust instantly. I've seen piston pins lock in piston to be unuseable in less than 24 hours, you must change the way you do things to prevent it.


----------



## Hobby Dude (Aug 7, 2019)

Just like watering down beer.....


----------



## New old husqy (Jul 7, 2020)

G-Mann said:


> After 5 years of running my Stihl FS45 trimmer and BG55 blower, both started running bad. Took the carbs apart and found that the diaphrams on both were quite hard and brittle. For a few dollars more, I replaced the carbs on both units. They now run great!
> 
> Could it be that ethenol gas at 15% be the cause of such a failure?


Yes ethanol gas is the killer of small engines I always run recreational fuel in my small engines a lot less trouble out of them


----------

