new saw new problems

[kayaklogger]

it's me again, the dufus who blew up his new 361 trying to mill doug fir.

So, my newest saw is a used 046 with a ported muffler, (what I should have got in the first place) it's really fun, the biggest saw I've used yet (now I want an 066, this IS an addiction) but, it's got a glitch, starts and runs and cuts and idles well when cold, but as it heats up it gets really hard to start and won't run without throttle. I posted this in another forum but it got buried pretty quick. Anybody here know what might be going on?

thanks for any advice

 

[Mike Van]

My 041 which ran pretty good got hard to start when hot - A new plug was the fix - Pretty cheap fix too -

 

[glennschumann]

I recommend a plug too. Been there, done that on an old Homelite XL - Hard to start hot but easy to start cold. Turns out it had the wrong plug in it. Got the right plug, and it is all good. Look up the correct one, and try that.

 

[lumberjackchef]

Try the plug but if does it again, Run the saw till it is warmed up, then pull the starter off, grab the flywheel while holding the body of the saw tight, so that it doesn't move, then jiggle it back and forth to see if you have any play in the bearings. I had an old Dolmar 120 that I modified and it was the best running mid sized saw I have had the pleasure of carving with. Well it had these same symptoms and I replaced the plug a couple of times and it seemed to work. But the last time I happened to pull the starter and found that the the bearings and seals were causing it to have a vacuum problem once they were up to temp. Hence the hard starts and idling problems. No amount of carb rebuild kits or adjustments seemed to matter either. Now shes on the bench about to get a rebuild! Hope that's not your problem but just thought you might want to check it out. Part of the gamble of buying a used saw is that you don't know what kind of maintenance it had or how many hours those bearing have seen or under what conditions the saw had been operating. Let us know.

 

[smithie55]

Beings it is a used saw, it sounds like the crank seals are bad.
Crank case is unable to maintain the proper vaccum pressure once the seals have warmed up.
I bought 2 used Stihl saws and had to have the crank seals replaced in both of them. They are not to awful expensive to have replaced.
Saw shop can run a pressure test on the crank to determine if that is the actual cause.

 

[Bambi]

Dumb Question

What are you running for gas and what is your oil mix? Gasoline has been a big issue for awhile. I have been using mid grade Mobil 89 octane for years with no problems and use the the standard 50:1 mix with no problems. The pumps sez 10 % ethanol which has been approved by most manufacturers. E85 is out there in some states, I haven't seen it, but its greats stuff for many cars but not for saws or power equipment. People assume that its 85% gas and 15% ethanol. Did a little home work and it ain't what many people think. It's the other way around 85% ethanol and 15% gas. It is Death for a saw or any power equipment, not set up for it. Cars have computers and some can compensate some can't.
Even though I use mid grade, I think they are sneakin in more alky. On two pieces of power equipment both 4 strokes I have had problems and according to some of the forums out there, the problems are caused by too much alky. With a 4 stroke it usually raises havoc with carbs and fuel pumps. In a 2 stroke not set up for it, other things happen. Temperature ambient or saw temperature will affect the alky more.
I would find out what gas that your saw center recommends and others in the area are using and go from there and like the others in this group a little less pressure and a tad more oil in the mix won't hurt.
Good Luck
Bambi

 

[BC_Logger]

Even though I use mid grade, I think they are sneakin in more alky. On two pieces of power equipment both 4 strokes I have had problems and according to some of the forums out there, the problems are caused by too much alky. With a 4 stroke it usually raises havoc with carbs and fuel pumps. In a 2 stroke not set up for it, other things happen. Temperature ambient or saw temperature will affect the alky more.
I would find out what gas that your saw center recommends and others in the area are using and go from there and like the others in this group a little less pressure and a tad more oil in the mix won't hurt.
Good Luck
Bambi

your talking about ethanol E10 gas right ? or a alkylate fuel ?

alkylate fuels are fine on 2 stroke and 4 stroke engines

http://www.aspen.se/Files/PDF/Productsheets/English/produktblad1_ENG_NEUTRAL.pdf

 

[Coalsmoke]

it's me again, the dufus who blew up his new 361 trying to mill doug fir.

So, my newest saw is a used 046 with a ported muffler, (what I should have got in the first place) it's really fun, the biggest saw I've used yet (now I want an 066, this IS an addiction) but, it's got a glitch, starts and runs and cuts and idles well when cold, but as it heats up it gets really hard to start and won't run without throttle. I posted this in another forum but it got buried pretty quick. Anybody here know what might be going on?

thanks for any advice

Has anyone else noticed that this particular problem, that almost seems like a heat generated vapour lock issue, is rather common among older stihl saws? I know when I ran in a large crew, some of us had husky and some stihl, and some like myself had both and quite a few of the older stihls would develop this problem. I just thought it was interesting and this thread reminded me of being in the bush fighting the same type of thing. Huskys would get hard to start in time, but once they were warm they ran like a wild horse.

 

[mtngun]

I experienced the so-called "vapor lock" issue on hot days a while back. I do think it is worse with E10 because ethanol seems to boil easier than real gas. I think the fuel is actually boiling inside the carb and I know it boils inside the gas tank, so that could explain the problem.

My Efcos are the most prone to balky hot starting, and there were days when they refused to start at all when they were hot. My Stihl still starts when it is hot, it just takes a few more pulls and maybe part throttle.

They seemed to want more fuel, so I adjusted the idle mixture quite a bit richer. It seemed to help with the hot starts.

In theory, the tank is vented so it should not build up pressure when fuel boils, but it does anyway.

 

[the westspartan]

I experienced the so-called "vapor lock" issue on hot days a while back. I do think it is worse with E10 because ethanol seems to boil easier than real gas. I think the fuel is actually boiling inside the carb and I know it boils inside the gas tank, so that could explain the problem.

My Efcos are the most prone to balky hot starting, and there were days when they refused to start at all when they were hot. My Stihl still starts when it is hot, it just takes a few more pulls and maybe part throttle.

They seemed to want more fuel, so I adjusted the idle mixture quite a bit richer. It seemed to help with the hot starts.

In theory, the tank is vented so it should not build up pressure when fuel boils, but it does anyway.

Had the same problem with my ms441 on a 92 degree day, cutt'n in the sun.

 

[olyman]

I experienced the so-called "vapor lock" issue on hot days a while back. I do think it is worse with E10 because ethanol seems to boil easier than real gas. I think the fuel is actually boiling inside the carb and I know it boils inside the gas tank, so that could explain the problem.

My Efcos are the most prone to balky hot starting, and there were days when they refused to start at all when they were hot. My Stihl still starts when it is hot, it just takes a few more pulls and maybe part throttle.

They seemed to want more fuel, so I adjusted the idle mixture quite a bit richer. It seemed to help with the hot starts.

In theory, the tank is vented so it should not build up pressure when fuel boils, but it does anyway.

me believes thats because the vent aint as big as the boiling is large--hence pressure--tip saw so cap is up--loosen slowly---let cool for about 1 min--tighten cap--then try to start--may take a few pulls--as its flooded---couple of my olys do the same thing----