stihl 046 starts-quits

[tractorhal]

I have 046, not used often. starts,runs then "pops" and quits. had worked ok. any thoghts before rebuilding carb? gas has 10% ethanal. use 91 octane 50-1,sometimes 2gals. gas instead of 2.5gals. same gas used in ms361, husky365, ms200t, 2@homelite super2. have heard ethanal may cause problems. was told by long time friend that Partner recommends the use of marine stabilizer. 

[sawcollector]

Verify that the impulse hose is OK, not cracked or off, and the same with the fuel line. It may have gotten brittle and old and cracked, so with the choke on some fuel gets pulled in but then the when open the saw goes lean and runs out of fuel. If it has been sitting a long time and the fuel is stinky then the nozzle in the carb may be restricted. It is very delicate so be careful how you clean it and do not blow high pressure air through it.
I posted the following in another forum but since you asked about stabilizer here is my experience with it:
I have a lot of small engines in my collection. Here in Chesapeake VA we switched to E 10 about 2 years ago. But before and after that I had trouble with carbs gumming up, sometimes in as short a time as a month.
I now follow this procedure and it works for me with the fuel here:
I buy a 5 gallon can of 89 octane name brand fuel. I do an alcohol test on it right there at the pump. I have yet to have over 6%. I then add a name brand fuel stabilizer, such as what B&S, STIHL, or Stabil sells. I mix my two-stroke in a 1 gallon can out of the 5 gallons I just brought home, with STIHL Ultra oil at 50:1. So now all my fuel has stabilizer in it.
Since I have been doing this for about 2 years now, I have pulled saws or trimmers out that have been sitting with this fuel in it for months and they start up and run fine. This has solved my problems for the short term.
For long term storage I use a vacuum tank to suck out the fuel and let the engine idle till it runs out of gas. I always pull the bar oil after cutting with a saw so it does not leak all down the shelves. I pull the plug and spray some sort of oil spray, such as WD-40 or equivalent in to the combustion chamber, and I pull the air filter and fog the crankcase the same way, and pull it over a few times to wet all the internals down.
Works for me!

I hope that helps, tractorhal.
Eddie

[ladylake]

If it started doing it after sitting a while I'd think a clogged carb, take apart and clean, most time you can get by without a kit unless the diaphrams are hard. Could also be a clogged filter or bad fuel lines.  Steve

[Al_Smith]

Chances are the carb diaphragm is as hard as a rock ,a common problem . A carb kit is rather inexpensive .Of course if you purchase it through a Stihl dealer it will cost about double or triple what everybody else charges .

[joe_indi]

Even though Organic Chemistry was not a subject that I liked very much, at the risk of sounding like a perfect ass, if my memory is right, ethanol  has a lot of Cs, Os and Hs in its structure right?.
Isn't there the possibility, that given enough time  all the Cs disappear leaving the Os and  Hs to come together as H20?
Joe

[Al_Smith]

Oh Joe you are funnin us again you sly dog ,you know . :D However when you look at it like that I guess you can burn water for fuel ,kind of .

[tractorhal]

thanks for info. took time to check saw today. tried to start it,no start. pulled plug to see if wet or dry. wet, and the electrode was even with the porceln,gap looked ok, pushed on porceln it went back into plug. put in new plug, first pull fired.