Stihl Is Changing Carburetors?

[SteveSr]

I have noted some operational issues with my MS260 Pro that appear to be carb related. Changing the position from horizontal to bar nose down seems to cause a large drop in idle speed. If the idle is not set almost dangerously high the saw is likely to stall. This seems to happen when the saw is fully warmed up. I also checked and mine does have the #56 fixed jet although this shouldn't make any difference in idle performance.

I talked to a tech service rep at Stihl in Virginia Beach and he basically indicated that this was a characteristic of the carb (Wt-403). He also mentioned that Stihl was going back to a 2 screw (h and L) design with limiter caps to solve some of these performance issues.

Have any of you seen or heard anything along this line? Are they changing from Walbro to some other manufacturer like Zama? On another puzzling note I saw a new MS260 *non-pro* with a 1 screw Intellicarb which is only supposed to come on the *pro* versions of their saws. Is Stihl trying to use up their inventory of the existing Intellicarbs before switching to the new 2 screw replacement? Inquiring minds like our want to know!

 

[Fish]

Sounds more like a fuel supply issue, like fuel line or tank venting
but I may be wrong, and usually am.

 

[Toddppm]

My non-pro 260 only has one adjustment screw too? Runs great though

 

[TonyM]

I had a brand new 026 PRO when they first switched to fixed jets. It did the exact same thing. It would run fine one minute, and like crap the next, and depending on position would richen or lean out as you describe. It also ran horrible when it was humid. It would either idle so fast the chain would spin, or it would stall. I finally fixed it by buying a SOLO 651!

 

[glens]

SteveSr,

It's a fairly common misconception that "fixed jet carb" equals "Intellicarb" but the they are completely separate features which sometimes co-exist but are never co-dependent.

That's just in case you care.

Glen

 

[alamo-kid]

new Stilhs

I looked at a new stihl catalog todayand it showed pictures of the new ms 270 and ms 280 they both seem to have 2 holes in the cowling for high and low speed adjustment screws....? I have never seen one in person so I'm not sure but could they have 2 screws? 165 say's all the new ones he has seen have had 1 screw...... but as I said before my ms 260 came with 2. any body seen one of these new saws. The new Stihl line up sure seems to have a lot of duplication in the same class of saw.... I wonder which one is on the way out. The 270 and 280 have white handles so I assume they are pro saws?


jeff

 

[glens]

Jeff,

I gave a 280 a good eyeball today.  It and the 270 have a completely new configuration.  The crankcase itself is mostly like the recent white-handled saws, but the oil tank half with the cap, and most of the starter encasement seems to be of a plastic material rather like in the (what would be) odd number saws.  The units on display both had spur sprockets and non-adjustable oilers.  I forgot to pop the airbox cover to see whether they have "Intellicarb"s but I don't doubt that they do.

The cylinder is oriented much closer to vertical (if not in fact completely) and I'd think that would throw the major imbalance-induced vibration of the crank counterweights at half-stroke into the fore and aft plane, thus rendering it largely non-noticeable.  I wonder if that isn't in large part why Huskies feel like they vibrate less (rather than owing entirely to the suspension).

The saw seems a little more "spread out" than other Stihls in the size range.

There are in fact two mixture screw holes and they are both populated with screw slots.

Glen

 

[daveb]

270/280

They still don't list the 280 on their website. The 270 they show looks like it has some kind of funky chain adjuster. Did you see this on the ones you looked at? Also the 270 is listed at 49.6cc, what is the 280?

 

[glens]

The funky chain adjuster actually seems like a nice feature for the occasional user, at least.  I've never spent any amount of time with them, but they make the tool-less fuel caps a little more sensible.

Okay, my sources show:

MS270C (C denotes "comfort" - hence the chain adjuster) and MS270CQS (same but with additional rear-handle "quick stop" brake release) at 49.6 cc making 3.5 hp.

The MS280 (standard chain cover) and MS280CQS (see above) are shown to be 54.0 cc making 3.75 hp.

Basic weights are the same, the "C" adds 0.2 lb and the "QS" adds another 0.3 lb, so the lightest is the MS280 at 11.6 lb.

They did not have any of the QS versions in stock, only the 270C and 280.  I forget now what the prices were, but think they were about $350 and $400.

I've never worked a QS model before, but am thinking for a couple of reasons that it must work against what would normally be the stationary end of the brake band.

Glen

 

[SteveSr]

Originally posted by TonyM
I had a brand new 026 PRO when they first switched to fixed jets. It did the exact same thing. It would run fine one minute, and like crap the next, and depending on position would richen or lean out as you describe. It also ran horrible when it was humid. It would either idle so fast the chain would spin, or it would stall. I finally fixed it by buying a SOLO 651!

TonyM,

I am glad to hear that I am not loosing my mind with this. I started using older 026s in a trail club that I work with. These ran great compared to the new ones I've seen. I guess that we can thank the EPA for this. I figured that I would eventually find an old carb to stick on it to make it run right. Sounds like Stihl is finally realized this and is changing carburetors. BTW, did you return your 026 to Stihl as defective or just sell it outright?

 

[treeclimber165]

Stihlman036 (Chris) has a couple extra old style carbs for the 026. I got one for mine and it now runs great.

 

[TonyM]

I sold it for $225 with a case to a guy a work with. He did some muffler mods to it and seems pretty tickled with it. It had cut maybe 20-25 cord of wood when I sold it.

 

[Kneejerk Bombas]

Originally posted by SteveSr
I have noted some operational issues with my MS260 Pro that appear to be carb related. Changing the position from horizontal to bar nose down seems to cause a large drop in idle speed

Doesn't this indicate the low speed jet is set too rich?

 

[SteveSr]

Originally posted by glens
SteveSr,

It's a fairly common misconception that "fixed jet carb" equals "Intellicarb" but the they are completely separate features which sometimes co-exist but are never co-dependent.
Glen

I do know what the difference is between an "intellicarb" and a non-intellicarb. I was just surprised to see one on a saw that wasn't supposed to have one.

 

[SteveSr]

Re: Re: Stihl Is Changing Carburetors?

Originally posted by Mike Maas
Doesn't this indicate the low speed jet is set too rich?

I tried all kinds of settings for the low speed mixture but it didn't seem to have any effect on this issue. It came setup way too rich from the dealer and exhibited the problem. I let it stay this way until it got broken in. I finally reset the low speed mix to where it should be and the issue continued. The only way to keep it from stalling under these conditions is to set the idle speed way up which causes the chain to run occasionally. I know this is not safe but it saves wear on my arm and the starter rope!

 

[glens]

Originally posted by SteveSr
I do know what the difference is between an "intellicarb" and a non-intellicarb. I was just surprised to see one on a saw that wasn't supposed to have one.

Steve,

I'm still a little unsure what you mean.&nbsp; That the non-PRO saw has the fixed-jet carb is not news, but if it had the IC cap and air filter, that <i>would</i> be.&nbsp; Are you saying the latter?

It's my understanding the the carb is the same part between the two versions of the saw model, and that the cap/filter are the only differences in the intake tract (and isn't it the same filter, with a knockout for the IC passageway?).&nbsp; It may be that they're using up stock in order to make a switch, but I'd think they would want to keep <i>some</i> around to cover repairs for at least a while.

Glen

 

[SteveSr]

Originally posted by glens
Steve,

I'm still a little unsure what you mean.&nbsp; That the non-PRO saw has the fixed-jet carb is not news, but if it had the IC cap and air filter, that <i>would</i> be.&nbsp; Are you saying the latter?

Glen

Yes, this was a regular non-pro MS260 with the carb vented air filter and intellicarb. When I pointed it out to the shop person he was surprised.