Makita-Dolmar Airfilter Woes

[rayIN]

This is a great forum that I have been reading for about 6 months. However this is my first post, and I'm seeking advice on finding the right airfilter. My problem is I'm sucking fine saw dust in the engine on a Makita-Dolmar DCS520. Stock filter is either folcked or nylon, neither of which is efficient enough to become clogged, rather the fine stuff passes right through - sometimes as early as after 1/2 tank of gas. I see and feel the dust in the carb troat. I'm a big fan of 2-stroke engines, and this 10lb saw, and would like to see it last as long as possible. I modified the muffler based reading this thread and it really performs well.

I've exhausted my search for fine dust leaks into the carb compartment, and can only guess I'm getting the fine saw dust through leaks that develop around the carb foam gasket when the engine vibrates.

I would like to go to a pleated paper filter - any suggestions of approximate sizes would be most welcome. The only think I can think of is to bother the guys at the Stihl parts counter to find something close, and modify that - or fabricate a new one out of a high performance vacuum bag rated at filtering drywall dust.

Thanks in advance,
RayIN

 

[rayIN]

I should be clearer - I meant that the dust must enter the carb compartment around the foam gasket that separates the carb from the compartment. I didn't mean to imply that I had a leak in any of the carb gaskets into the carb. It's a WT 76.
Thanks again,
RayIN

 

[Dolmar_Tech_Mgr]

This is not the first time i have heard of or seen this problem, I will contact the factory on Monday to see if there is anything we can do to help improve on this situation. This family of saws is due to replaced by a new family very soon. In what i have seen of this problem it appears that the debris is entering between the filter seperation points. I have used some vasoline on the filter halves where they press together and this has had good results.
Terry

 

[rayIN]

Terry,
Thanks for the reply. I wrap the halves with teflon tape. This is my only saw with flocked airfilters - are these less efficient?
Thanks,
Ray

 

[Dolmar_Tech_Mgr]

In all our chainsaws we use only two types of filters, the Flok which is standard equipment for producution and this is the best filter we have. The other filter is nylon and is more for winter months to keep the filters from icing up.

Terry

 

[johncinco]

I mentioned this before with mine, but I think it is buried somewhere. I have the makita version of the same saw. I found that the nuts on the sides of the filter cover had been over tightened previously, and between that and heat from the engine the cover had warped, allowing just about any size chip/dust to pass into the compartment. I tighten them down just snug, and then tape off the seams with duct tape and it works great. In addition, which will be the gurus only solution, is to make sure your chain is sharp. Stealing their thunder for a second, a sharp chain makes chips, not dust. While I agree 99.9% with that statement and believe it to be true, you are always going to get some dust no matter what. If you plan on buying an extra filter let me know I have the part number and can email you. I called a dealer, paid with visa and the mailed it to me. Cheers, JB

 

[rayIN]

Terry, JB
Thanks for the responses. I have 3 airfilters and still have the problem. I haven't tried to seal the top cover with duct tape, but it doesn't seem warped - besides it's done this since it was brand new. I do alot of clean-up work and usually cut into middle rot, which is pretty dusty. I'm experimenting with vacuum bags and simply wrap the existing filter body and hotglue the seams. I'm not sure how well it will breathe. Perhaps I'll have to look into a couple of different grades of vacuum bags. I'll post if I find anything that works well.
-Ray

 

[Tony Snyder]

You don't have to be a factory tech rep to know (no offense intended) that flocked filters have their drawbacks, particularly if wetted to clean and then expected to return to original effectiveness. The fibers lay down and form an air obstruction, or dislodge and turn into screen door mesh.

 

[jokers]

Hi Tony, I would suppose that it is somewhat related to the shape of the filter or brand but I have good luck washing my flocked filters at the car wash. Hit them at a steep angle with the pressurized soapy water and they usually end up looking new. After they dry out I give them a thorough check with a light from the inside or backside to make sure I don`t have any holes and look for any flocking that needs to be combed with an old toothbrush. If you have the angle of the water right the fibers don`t even lay down.

Russ

 

[Saw Man]

Perhaps contrary to some belief, a dirty(not clogged) air cleaner element is actually more effective.

Certainly wouldn't pressure wash any flocked filter. It is too easy to remove the flocking, and only if carefully viewed against a bright light, or thru low magnification will you see the shafts of light shining through.
Those are holes that don't belong there.

Most air filter elements can be gently brushed off with a soft bristled brush (not an old tooth brush), and should occasionally be cleaned using hot soapy water.

On two cycles there is a condition "fuel blow back" that wets the air filter. As the gas evaporates, a very light oil film is deposited. As time goes on the air filter becomes slowly clogged due to the mixture of gas/oil/and dust.

Hot water helps soften the dirty material, AND speeds up the chemical action of the soap.

Some of the best soaps are simple dish washing liquids. They dissolve/mix easily, are good on oils/ fats, and create lots of bubbles. Those bubbles (fancy name-collidal suspensions) actually
help to 'catch & float' dirt particles away.

Sometime, just wash a filter in gas. Then, in a seperate container, wash it in a hot soapy solution. Let soapy container set for a while. Rinse in clean water. Let rinse water set also.
You'll be surpised at the results.

As to the Dolmar air filter, and most splitable filters, they are subject to alot of vibration. They can flex/vibrate at certain rpms, and allow some leak paths.
Most splitable filters have a spot or tabs used to split them, and if not used, the filter can be permanently damaged.
Check out the inner seam edges for damage/distortion.
Halves should give the feel of a firm 'snap', and squeeze it ALL around the edge for a positive good seal.

Another area is the two slotted Torx fasteners that go thru the filter assembly. It is possible to overtighten the screws, andat some point in time the filter can distort at those holes, or the surrounding area where the filter fits in/on the elbow.
Compare profile, and stiffness of new vs old.