Typical symptoms of 345/346 etc intake failure?

[Adamam]

I've been working on a few 345/346/353 type saws recently, some of which have piston/cylinder damage which seems to have been from the common intake boot/clip failure.

 

I haven't actually seen a running saw with this problem though until (maybe) today. I have a 345 that doesn't want to start, then starts and runs high for a few seconds then dies.

 

Obviously this could well be an air leak (maybe from the clip/boot which is the old plastic type) but it's so extreme (start/scream/stop) that I'm not sure.

 

Does this clip/boot failure often result in such an extreme air-leak? I assumed it would be more subtle...

 

The pot and piston are good.

 

[SawTroll]

I've been working on a few 345/346/353 type saws recently, some of which have piston/cylinder damage which seems to have been from the common intake boot/clip failure.

 

I haven't actually seen a running saw with this problem though until (maybe) today. I have a 345 that doesn't want to start, then starts and runs high for a few seconds then dies.

 

Obviously this could well be an air leak (maybe from the clip/boot which is the old plastic type) but it's so extreme (start/scream/stop) that I'm not sure.

 

Does this clip/boot failure often result in such an extreme air-leak? I assumed it would be more subtle...

 

The pot and piston are good.

 

 

Major air leak.

[spudulike]

Typically an air leak will initially manifest itself as a reluctance for the revs to snap back down to an even idle on releasing the throttle. This may be followed by the engine screaming and reaching higher revs than it should.

 

If the saw hasn't seized my now, you may get bogging in the mid range or no high revs at all.

 

Carb settings will start going out of the window with the L screw requiring an extra half turn or so to get the idle to behave but the saw will never have a stable idle.

 

The intake is a bit of an achilles heel of this range of saws but much of it is down to poor fitting of the manifold with the impulse nipple on the manifold often being crushed!

[SawTroll]

Typically an air leak will initially manifest itself as a reluctance for the revs to snap back down to an even idle on releasing the throttle. This may be followed by the engine screaming and reaching higher revs than it should.

 

If the saw hasn't seized my now, you may get bogging in the mid range or no high revs at all.

 

Carb settings will start going out of the window with the L screw requiring an extra half turn or so to get the idle to behave but the saw will never have a stable idle.

 

The intake is a bit of an achilles heel of this range of saws but much of it is down to poor fitting of the manifold with the impulse nipple on the manifold often being crushed!

 

The issues mainly disappered, after the 2006 update.

 

SB, 357 XP, 359, 353, 346 XP,

Partition wall and clamp for intake system,

2006-03

 

The existing intake system on 357XP, 359,353 and 346XP currently consists of an integrated plastic clamp in the partition wall. As the clamp is made of plastic, there is a risk of deformation. This results in impaired clamping force against the cylinder, which in turn can result in leakage in the intake system. To prevent this from occurring, we have now introduced a metal clamp and a new partition wall.

 

The new partition wall is made up of polyamide with 30 % fibre glass.

The new clamp is a hardened steel clamp. The new material and the design of the clamp reduce the risk of deformation and the subsequent risk of leakage.

 

Full replaceability prevails.

Introduced from serial number:

357XP 061100201

359 061100001

353 061100001

346XP 061100001

 

New part no. Description Excl. part. no. Remark

537 25 13-02 Partition wall, intake, complete New spare part

537 43 88-01 Clamp, intake New spare part

 

Spare part, partition wall, part number 537 25 13-01, has been discontinued and is replaced by part number 537 25 13-02.

 

[Adamam]

The issues mainly disappered, after the 2006 update.

 

Then all that was left was the issue of the skinned knuckles and bind fury cause by that wretched, wretched metal clamp.

 

 

Although the squashed/skewed impulse nipple is still a problem, even with the metal clamped version.

[SawTroll]

Then all that was left was the issue of the skinned knuckles and bind fury cause by that wretched, wretched metal clamp.

 

 

Although the squashed/skewed impulse nipple is still a problem, even with the metal clamped version.

 

Yes, sort of - but you can always use a screw type clamp in its place, to avoid the knuckle damage.

[Adamam]

Yes, sort of - but you can always use a screw type clamp in its place, to avoid the knuckle damage.

 

Do you know for a stone cold fact of a screw type one that fits? The Stihl 026 type is too small (just), and generic industrial type version are always too wide across the band...

[spudulike]

Do you know for a stone cold fact of a screw type one that fits? The Stihl 026 type is too small (just), and generic industrial type version are always too wide across the band...

 

Fitting them is easy, you just need finesse:sneaky2:

[SawTroll]

Do you know for a stone cold fact of a screw type one that fits? The Stihl 026 type is too small (just), and generic industrial type version are always too wide across the band...

 

Jonsered 2077, 2083 and other saws in that "family" (Partner and Poulan Pro) is what Husky mentioned in a TI once - and I have been told that at least some Stihl model ones (believe 038 is one, but memory may be off) will fit as well.

 

Of course it doesn't have to be a chainsaw related one, as long as the diameter and width is compatible.

[adw]

Dont mess about with non standard clips, learn how to fit the correct clip, its not that hard once you have done a few, but as has been said its more importent to get the impulse into the cylinder before fitting the housing.