Dolmar 7900 HD Air Filter Kit - Pics and Videos

[MCW]

New video:

Now you'll get to see how nice this filter kit works. It's just as good as the "others" in my opinion.


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http://www.youtube.com/watch?v=xVGtM9FyWio

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:greenchainsaw:

Good video Woodchucker.
Apologies for basically hijacking parts of this thread but just got back from the Inlaw's farm and gave the HD filter setup a good workout on very dead, very dry, Pink Gum (same filter penetrating ability as dead, dry Redgum).
Basically I was cutting about a 30" stump at full throttle with the saw on it's side using my right hand to cut (whoops, bad!), and catching the dust/chips coming out of the chip guide with my left hand, then pouring the mess into the intake.
I know it sounds rough but I did this until my new Snellerized 7900 slowed, stopped, then wouldn't restart (nearly a tank and a fair pile of 1" Pinkgum cookies!)
Have attached pictures of the filter and prefilter. I had kept my thoughts on this filter's ability to pass the dead, dry, Aussie Redgum/Pinkgum etc test to myself as I honestly expected it to fail but it didn't. It passed with flying colours.
Have attached pictures. I also took a video of me blowing out the prefilter with an air compressor. I haven't attached the video as it was poor quality but what was blowing out of the prefilter was like pink/red talcum powder.

As you can see the prefilter is basically blocked solid with the dust...

The photo of the intake looks to have fine particles in it but I can assure you it hasn't. There was a film of your standard 2 stroke oil lining the intake and I had my finger inside getting it out then wiping it off on white paper. No hint of pink wood dust at all. Some of the visible larger particles fell off when removing the filter. The particles that have been known to get through filters from Redgum etc are that small they cannot be seen with the naked eye. All you see is a general discolouration of the intake tract.

SUMMARY: You will not find better filtration on a chainsaw than this as far as I'm concerned. Maybe equal, but not better. Many top level saws (Huskys, Stihls) have had their filters fail to stop particles as fine as these in Australia. Woodchips are easy

 

[Andyshine77]

That looks like dust from cutting bricks, not wood.:jawdrop: That truly looks like the ultimate test for any saws filtration.

 

[MCW]

That looks like dust from cutting bricks, not wood.:jawdrop: That truly looks like the ultimate test for any saws filtration.

Sad part is Andy it only gets worse when using a blunt chain
This chain was cutting well!

 

[tdi-rick]

Looking good Matt !

 

[AUSSIE1]

Good stuff Matt.
Is the main filter similar to the husky material?
That prefilter material could be the go for the large Husky's we are having troubles with.
What is the prefilter made of?

 

[MCW]

Good stuff Matt.
Is the main filter similar to the husky material?
That prefilter material could be the go for the large Husky's we are having troubles with.
What is the prefilter made of?

I'm not sure Al. It isn't the felt like my 3120 but it is definately a paper element. Nothing is mentioned in the small bit of literature that came with the kit.
The prefilter is also different to any I have seen but to be honest that isn't too many at all
The prefilter certainly does get more dust out than I thought it would. Only problem I can see is where it is sewn together and doesn't fit perfectly against the main filter. All of the larger chips etc congregate around this point then have easy access to the main element. You can see that in my pictures. Wherever you have the seam pointing is where you'll have the highest build up of crap on the main element.

 

[WoodChuck'r]

Rock on wit yo bad self MC-Dub. Those pics are badass.


Yay for Dolmar.

 

[WoodChuck'r]

Apologies for basically hijacking parts of this thread

Don't mention it. Now if your saw pics were of an orange saw I think that only then we would have a problem.....

Just kidding.


We're pimping Dolmar, this thread is for a great cause IMO. :greenchainsaw:

 

[MCW]

Don't mention it. Now if your saw pics were of an orange saw I think that only then we would have a problem.....

Just kidding.


We're pimping Dolmar, this thread is for a great cause IMO. :greenchainsaw:

Yep
If this doesn't stick it fair up the anti-Dolmar brigade's A*S then nothing will.
Although I don't expect their attitude to change

 

[056kid]

A comparison with the leading competitors in the red gum is a good idea...

 

[TraditionalTool]

A comparison with the leading competitors in the red gum is a good idea...

Yeah, and masturbating will get the same results possibly...but who cares what the other competitor saws will do, he uses a Dolmar and not a Stihl.

That saw looks like it cuts just fine and he was showing how well the filter system works on it. Do we need yet another demonstration of Stihl's great filtering system?

Better yet, why don't you show us how great your Stihl filters the dust in similar cutting conditions?

 

[tdi-rick]

A comparison with the leading competitors in the red gum is a good idea...

Matt has a couple of Huskies too, a 3120 and a 'new' 390.

There's more than a number of destroyed 660's from Red Gum dust ingestion around the country here, and as Matt can attest, Husky wont honour warranty unless filter oil has been used on the outer.
Where do you think the HD Stihl filter kit originated from ? and they are still lunching themselves, Rooshooter did another one a few months back. The Stihl HD kits were a response to a problem in Australia and South Africa, and FWIW dealers steer pro customers away from 361's due to inadequate filtration in the drier areas too.
It's an all makes issue.

 

[056kid]

Yeah, and masturbating will get the same results possibly...but who cares what the other competitor saws will do, he uses a Dolmar and not a Stihl.

That saw looks like it cuts just fine and he was showing how well the filter system works on it. Do we need yet another demonstration of Stihl's great filtering system?

Better yet, why don't you show us how great your Stihl filters the dust in similar cutting conditions?

Stihl filter systems are terrible compared to the system of say a 372...

I dont know why you think that I am a stihl nut..

 

[blsnelling]

It's a known fact that air filtration is a real problem in the seriously hard woods of AU. So that comparison has already been done. If this filter didn't let red power through, then it's superiour to the competition. Pretty simple.

 

[MCW]

Many of the saws Ive heard of having issues are larger saws like the 660, 880 etc. Without filter oil I'm sure my 3120 would suffer the same fate.
It was only the other day in this thread that Al (Aussie1) mentioned that he had been having trouble with the larger Huskys which is news to me.
My 5100-S also needs filter oil to keep the dust at bay as did the stock 7900 filters.
The only stock filter system I've seen that can keep this gear at bay is on my little Poulanesque McCulloch 2316AV which is an oiled foam filter. Now that's sad
I think the Husky 372's do OK.
One thing Bob (BobL) mentioned a while back which I thought was a good comment is that the bigger saws suck more air, suck more air HARDER, and may be able to pull this dust through the filter easier, unlike the smaller cc saws. Not sure about this but makes sense to me, as Bob normally does.
Unless he gets in Scientist mode then me no comprehendy

 

[Adirondack]

Thanks MCW,

Good work on putting the filter to the real test. Dolmar should give you some free stuff cause I think you will sell a lot of filters. I know it has convinced me to buy the upgrade filter with my next purchase. Thanks for all your posts.

 

[AUSSIE1]

Many of the saws Ive heard of having issues are larger saws like the 660, 880 etc. Without filter oil I'm sure my 3120 would suffer the same fate.
It was only the other day in this thread that Al (Aussie1) mentioned that he had been having trouble with the larger Huskys which is news to me.
My 5100-S also needs filter oil to keep the dust at bay as did the stock 7900 filters.
The only stock filter system I've seen that can keep this gear at bay is on my little Poulanesque McCulloch 2316AV which is an oiled foam filter. Now that's sad
I think the Husky 372's do OK.
One thing Bob (BobL) mentioned a while back which I thought was a good comment is that the bigger saws suck more air, suck more air HARDER, and may be able to pull this dust through the filter easier, unlike the smaller cc saws. Not sure about this but makes sense to me, as Bob normally does.
Unless he gets in Scientist mode then me no comprehendy

Sorry Woody for the hijack.

Nothing passes the filter on the 371.
The ported big bore 371 I would assume is sucking alot more than std, possibly similar to the 385.
The amount the 385 lets through is worrying, same as the 395.

Would be interesting to see how the 7900 kit filters wiithout the prefilter.

 

[tdi-rick]

<snip>
Would be interesting to see how the 7900 kit filters wiithout the prefilter.

I'm guessing the same, it'd just load faster.
That's how two stage filtration works generally.

 

[AUSSIE1]

I'm guessing the same, it'd just load faster.
That's how two stage filtration works generally.

Yeah I understand the principal of the two stage, but would not have thought the prefilter would prevent the "fines" from getting through the secondary, but not saying it would.

Usually the prefilter being more open, catching most but the secondary catching the fine dust.

Tis why I was saying would be interesting to see how it would perform with out the pre filter.

 

[MCW]

Thanks MCW,

Good work on putting the filter to the real test. Dolmar should give you some free stuff cause I think you will sell a lot of filters. I know it has convinced me to buy the upgrade filter with my next purchase. Thanks for all your posts.

No worries mate. Not after free stuff, just trying to help out 6400-7900 owners with possible filtration problems and to stick it up the anti Dolmar boys who have used the average standard filter setup to bag them
As I mentioned, by passing this test I can't think of any other situation in sawing where it would fail?

I'm guessing the same, it'd just load faster.
That's how two stage filtration works generally.

I agree Rick. If I removed the pre filter it would just block faster I think. I'm actually surprised at just how much dust the pre filter seems to block.