My stihl won't run on Aspen - problem solved

[Marcl]

I'm sorry this is not a chainsaw but I wanted to get as much input as possible.

 

Today I bought a 5l can of Aspen, but my HS45 simply won't run on it. It took me 20 mins to start it. Only starts if I press the throttle and when it does start, it only revs enough to just move the blades. It coughs and misfires terribly.

 

So what's going on, does anyone know?

 

Thanks,

 

Marc.

[Rich2484]

carb issue. may need a tweak. how long has it been running on pump fuel?

 

the fuel to aspen change may have let the rubber parts...oh i cant be arsed to type all this.

 

using pump fuel then aspen causes the rubber bits to emss up...

[Eddy_t]

Generally, pump petrol rots any plastic bits, but the petrol keeps it in the right shape / flexibility, switching to aspen on a machine that has been run on pump fuel for a while can cause these things to shrink or stiffen, so you'll either need to retune or get a new carb kit

 

 

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[Marcl]

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.

[Eddy_t]

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.

 

No, but aspen needs to be tuned richer on the L screw, and yours is probably set a little lean on normal fuel, hence the reluctance to start

 

 

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[Marcl]

No, but aspen needs to be tuned richer on the L screw, and yours is probably set a little lean on normal fuel, hence the reluctance to start

 

 

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I'm going to play with it tomorrow. I put it in my brush cutter (Stihl 4mix) And that runs ok , a little low on tick over.

 

Marc.

[spudulike]

This operation can go 100% fine or you can get issues with leaks and poor running.

 

Try a retune of the carb and go from there, if still bad, then the carb may need new rubber parts including diaphragm and fuel line.

 

One thing I find strange is the time interval of pulling out the fuel and replacing with Aspen, I would expect any poor running to happen after the Aspen had time to have an effect.

 

You may have other issues but retune and go from there and you may need to replace parts if necessary.

 

Just done a MS260 - no issues at all but it had been dry standing for a while!

[GardenKit]

I really doubt the problem is actually down to the Aspen.

I have converted many 100's of machines (truly!) to Aspen and NEVER had one that would not start because of it.

 

Yes, I have had to retune a few to optimise their running and tick over, but they always start.

 

And as others have said, the rubbers can age once the petrol is removed, but not instantly. Problems with rubbers would not appear for many days. And problems with the rubbers and diaphragms are not the norm.

 

I reckon your machine has either flooded, or a little dirt from the bottom of the tank has moved through into the carb and its pure, but unfortunate, coincidence.

 

Hope you resolve the problem quickly and have success with the Aspen.

[Marcl]

This operation can go 100% fine or you can get issues with leaks and poor running.

 

Try a retune of the carb and go from there, if still bad, then the carb may need new rubber parts including diaphragm and fuel line.

 

One thing I find strange is the time interval of pulling out the fuel and replacing with Aspen, I would expect any poor running to happen after the Aspen had time to have an effect.

 

You may have other issues but retune and go from there and you may need to replace parts if necessary.

 

Just done a MS260 - no issues at all but it had been dry standing for a while!

 

This is what baffles me it was literally running on Stihl red mix, ran it for 5 mins just to pay attention to the smoke and smell. Switched it off, emptied the tank had a brew, filled it with Aspen and it would not start. After 10 mins It started but ran terrible.

 

Marc.

[GardenKit]

To be fair, I often get machines that play up only after they have been refilled, whatever fuel they are running on.