Stihl carb settings keep getting lost

[MarkB]

Today i grabbed my Stihl 039 from storage to do some cutting. The saw started fine and runs ok but after it warmed up the idle was way to fast. I had to turn the idle screw back at least 2 full turns.

I'm really sure when i put it away a couple months ago that it was tuned perfect. I store my saws without any gas if i put it away for a few months.

I also noticed this behaviour with my Stihl km130 hedge trimmer. Every time i grab it from storage i have to retune the carb.

I mix my own fuel (e5 gasoline and Stihl oil)

Is it normal to retune the carb after storage?

 

[Natster]

Probably was a gunked up low speed jet. Leaning it out, at idle. I'd remove the low needle, spray carb cleaner into it. And run star tron in all my saw gas. Ethanol has forever messed up things. This is fixable, but, when fuel clabbers, it clogs things up. No, I don't work for star tron. I just use it.
Nate

 

[HarleyT]

Today i grabbed my Stihl 039 from storage to do some cutting. The saw started fine and runs ok but after it warmed up the idle was way to fast. I had to turn the idle screw back at least 2 full turns.

I'm really sure when i put it away a couple months ago that it was tuned perfect. I store my saws without any gas if i put it away for a few months.

I also noticed this behaviour with my Stihl km130 hedge trimmer. Every time i grab it from storage i have to retune the carb.

I mix my own fuel (e5 gasoline and Stihl oil)

Is it normal to retune the carb after storage?

Do you run the carbs dry before storing?

Do you start back with fresh fuel, not fuel sitting in the can for a few months?

 

[Deleted member 117362]

Are you tuning to adjust for an air leak?

 

[Ted Jenkins]

It has always proved a very bad idea to leave any thing dry. Carburetors were never intended to be dry. If in doubt add some stablizer when put into storage. Thanks

 

[alexcagle]

Humidity, temperature, different fuel, all are factors. -or maybe your hearing aide needs batteries?.....

It has always proved a very bad idea to leave any thing dry. Carburetors were never intended to be dry. If in doubt add some stablizer when put into storage. Thanks

Oil residue is enough to keep the innards in good shape.
I started an old Mc Culloch that had been in a box in storage since 1966 that started and ran with zero issues. It was run dry, then stored. I could hardly believe it myself. This is it, and it is pristine.


It's the yellow one in my photo album on my profile page.

 

[MarkB]

I allways run it dry to get the fuel from the carb before storing.

I will do a pressure test tomorrow on the 039 just in case.

Can you just take out the adjusting screws and spray with carb cleaner? I never done that before when cleaning a carb...

 

[FlyingDutchman]

X2. Evaluate for air leak if problems continue. Was a crank seal on my MS290.

 

[MarkB]

I can't say that i never use mixed fuel that is a few months old, but my other Stihls don't seem to mind.

 

[MarkB]

No air leak on the housing but i found a leak at the bottom carb seal. Not sure if this caused the problems with the settings but i will order a carb kit to fix it anyway.

 

[grizz55chev]

No air leak on the housing but i found a leak at the bottom carb seal. Not sure if this caused the problems with the settings but i will order a carb kit to fix it anyway.

Not likely the problem, a vacuum test is in order. Searching for the right carb settings is a classic sign of an air leak leading to a run lean condition.

 

[trains]

Ive had saws that were running fine one day, then the next day after running, they were out of tune, would stall etc.
seems the fuel dissolved some dried out crud in the adjusting screws area overnight and it needed another minor clean and readjust and all good then.

Also been hit by mud daubers building a nest on the throttle linkage assy, that was fun, checked all the usual exhaust exit / screens etc.

Edited to add, is E5 gas ethanol gas, or ethanol free ?

 

[MarkB]

I did a VAC test and no leak.

E5 is 5% ethanol. I have never seen ethanol free gas here in the Netherlands at the gas stations but then i never really looked for it either.

I also cleaned the adjustment screws inserts with carb cleaner as some of you suggested.

I will know more when i installed the carb kit. Will let you all know.
Thanks for all the suggestions.

 

[MarkB]

I installed the carb kit and it looks better. But the real test will be when i put it away for a while and start it then.

I must correct one thing i said in my previous post: E5 gas here in Europe contains a maximum of 5% ethanol. And there is ethanol free gas to be had at most bigger gas stations. This is often called Super 89 gas or something similar. It is more expensive but i will be using this in the future for my 2 stroke engines. This gas also has more octane (89) instead of the euro95 (95) gas. I think this is a good thing from what i read here on the forum.