My stihl won't run on Aspen - problem solved

[Eddie@aspen]

The machine is about 2 years old but only has about 40 hours on it now. Been on normal stuff from new. Would effect it that quickly? I was running the saw then I emptied the tank filled with Aspen and it would't start, 5 mins after.

 

Marc.

Hi All,

 

I called in on Marc at home last week had a great chat and explained Aspen in more detail.

Then trained RedBlade mowers on Aspen.

 

Great guys and I feel that there was a misunderstanding about tuning Marc's HS45 and possible costs.

 

Marc's HS45 has a date of manufacture of 2006 so is not 2 years old as he first thought.

When RedBlade looked at Marc's HS45 the carb was flooding and that was why the engine would not run. A carb clean and a new Stihl carb kit was fitted by RedBlade Mowers.

The machine was then tested and left to sit to see if the flooding was fixed.

All fine and Marc now has his machine back.

RedBlade Mowers have covered the cost in full and Marc has not had to pay a penny.

The guys at Redblade Mowers are first rate and please use them if you are in the area!

[Steve Bullman]

*Edited title as its slightly misleading

[Marcl]

Yes thanks, I tried to edit the title but there is no edit button.

 

@Eddie. Thanks for your time with this issue. And it was great chatting with you. I was a bit miffed to find out my Stihl is over six years old. I bought it after I moved here and I have only been here 4 years! I guess it's probably a good thing as from what I understand new Stihl stuff is crap compared to the old stuff.

 

The guy from Redblade say's he does not know what went wrong and that I was probably very unlucky. Anyhow all good now.

 

Thanks again,

 

Marc.

[Eddy_t]

Yes thanks, I tried to edit the title but there is no edit button.

 

@Eddie. Thanks for your time with this issue. And it was great chatting with you. I was a bit miffed to find out my Stihl is over six years old. I bought it after I moved here and I have only been here 4 years! I guess it's probably a good thing as from what I understand new Stihl stuff is crap compared to the old stuff.

 

The guy from Redblade say's he does not know what went wrong and that I was probably very unlucky. Anyhow all good now.

 

Thanks again,

 

Marc.

 

I have found polymer precipitate in carbs before, so I would assume the petrol has attacked the fuel lines and carb diaphragms, and using aspen has caused it to collect on a single area, in your case the needle, I have found it on jets, the throttle butterfly and on the needle arm spring before

 

 

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[Marcl]

I have found polymer precipitate in carbs before, so I would assume the petrol has attacked the fuel lines and carb diaphragms, and using aspen has caused it to collect on a single area, in your case the needle, I have found it on jets, the throttle butterfly and on the needle arm spring before

 

 

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Could be Eddy, as it just kept flooding. I think the Aspen maybe dislodged something or even created a minor chemical reaction in the carb, who knows, but it's working now so i'll stick with it.

 

Marc.

[GardenKit]

Its probably not the case here, but worth noting anyway.

 

There are some chinese fuel filters that have been attacked quite quickly from the ethanol in petrol.

 

The engineers at Mitox UK identified this problem as some machines were exhibiting erratic running. Sometimes they were OK and sometimes not.

 

It turned out that the 'flock' in the tank filter was breaking down and getting trapped on the mixture screw seats causing issues. Retuning the carb would release the blockage for a while but then it would return.

 

It was too small to see in the carb, but could sometimes be seen making its way along the fuel line.

 

Ethanol is a killer to fuel systems and some materials are less tolerant than others and many 'after market' filters are of chines origin.

 

The Mitox ones have been altered in their composition to resist the ethanol.

[Eddy_t]

Whilst it may not be the case, it's entirely plausible, when you think that pump fuel degrades plastics, one molecule per micrometer per year isn't a lot, but 4 years on, with a few inches of fuel line, you only need one molecule to stick in the wrong place to cause a build-up, especially with the main solvent removed, but most would pass through the combustion chamber.

 

I often wonder if you were able to remove the pump fuel in the aspen demo kit what would happen to the dissolved (and precipitated) packing foam, would it set, or remain in a fluid state, and surely this must happen inside the carb?

 

 

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[GardenKit]

To be fair to established manufacturers such as Stihl, they have been aware of the ethanol issue for some time and have tried, with some success to engineer materials that have more resistance to the solvents in petrol.

 

The older machines such as the 039 I owned a while ago had an older type of plastic which dissolved more readily. I often find the gauze filter of these to be blocked with a pure white residue which recombines to form a semi solid mass.

 

I think I posted a pic of this around a year ago in my 'one reason I use aspen' thread.

 

But despite the best efforts of the chemists it seems that the ethanol still has some effect even on modern plastics.

[peatff]

But despite the best efforts of the chemists it seems that the ethanol still has some effect even on modern plastics.

 

Why doesn't the problem manifest itself in motorbikes and cars same as it does in chainsaws ?

[Dan Earp]

Possibly thinner materials in the chainsaws ?