Shindaiwa 490 air filter question

[NWPA Tim]

I bought a Shindaiwa 490 recently and decided to file the chain and clean it after the first 2 tankfuls. I got a surprise when I took the air filter out and found sawdust in the carb. After doing a search here it I see that it is not unheard of.
Here is my question: the parts list shows an o-ring where the air filter fits the carb, but mine does not have one. Seems to me that this would let unfiltered air along with dust bypass the filter. Can someone here with a 490 tell me if they have an o-ring on theirs?

Thanks.

 

[shindaiwadealer]

Hello and welcome to AS. This saw has to have the o-ring installed on the black plastic elbow that the filter sits on to keep the particles from seeping past. Also, if you have the original nylon screen type filter, replace it with the optional flocked upper and lower halves. Parts numbers 69020-98321 (upper), 69020-98331 (lower). That should solve all your filtering problems.

 

[JohnnyBoy1986]

:agree2:

 

[buckwasp]

Had/have the same problem

I have the o-ring and the upgraded flock filter and still have a very fine sawdust build up in the throat of the carb. I'm at a loss of what else to do or why there is still dust making it's way through. I actually had the top end rebuilt under warranty. I was running opti mix and the saw was no more than a month old. I wasn't running lean either, but was using the original filter. If you come up with a solution then please let me know.

Buck

I bought a Shindaiwa 490 recently and decided to file the chain and clean it after the first 2 tankfuls. I got a surprise when I took the air filter out and found sawdust in the carb. After doing a search here it I see that it is not unheard of.
Here is my question: the parts list shows an o-ring where the air filter fits the carb, but mine does not have one. Seems to me that this would let unfiltered air along with dust bypass the filter. Can someone here with a 490 tell me if they have an o-ring on theirs?

Thanks.

 

[NWPA Tim]

Thanks for the replies.
I plan to get the better filter before using the saw again. I see only 2 ways dust gets into the carb: through the filter or around it. I will put some grease on the o-ring to make a better seal.

buckwasp, was the dust the cause for you needing the rebuild?

 

[buckwasp]

dust in the carb.....

I don't know what else it could have been. Carb was adjusted per specs through the business I bought it from. I saw no signs of it being out of spec either. There was no doubt on the oil/fuel mixture. I use opti mix with good ole fresh 87 octane. I bought the saw brand new and hadn't probably put more than a total of 12 hours on it when it lost compression. I know of one other 490 from the same business that needed a new piston/cylinder. I don't believe his was warranteed even though he had it less than one year because he said he 'might' have used older mix gas. I kind of think he might have gotten the shaft myself. I'll run a little grease around the o-ring next time I go out and let you know the results. I know for a fact that there has been a little dust in the carb and my o-ring is there and I am using the new h.d. flocked air filter. It feels like I get a good seat when the air filter goes into place.

Buck

Thanks for the replies.
I plan to get the better filter before using the saw again. I see only 2 ways dust gets into the carb: through the filter or around it. I will put some grease on the o-ring to make a better seal.

buckwasp, was the dust the cause for you needing the rebuild?

 

[shindaiwadealer]

Make sure that both upper and lower halves are securely snapped together too. I have a customer that every time he takes the filter apart to clean it he never completely snaps it back together. The filter medium is excellent at filtering even the smallest of particles. If the medium is punctured, excessively cleaned to the point that the filter is wore out, the filter isn't assembled properly and/or installed improperly, then you will get some fine particles past it and into the engine. I don't know what else to tell you if you have checked all these conditions.

 

[NWPA Tim]

Update:

I ordered the better filter and my dealer offered to clean the carb, install the filter and check the saw over, which they did. I have been using the saw a lot the last couple of weeks and find dust in the carb each time I check. The o-ring is in place, the filter is snapped together tightly and pushed firmly into place. I find dust inside the filter directly opposite where it fits onto the carb, almost like it came from there.

I probably should take it back, but I have scored a large amount of cherry and oak tree tops that need removed quickly. With three of us getting it after work, it is first-come, first-served.

 

[NWPA Tim]

By the way, i couldn't ask for a better running saw.

 

[shindaiwadealer]

Update:

I ordered the better filter and my dealer offered to clean the carb, install the filter and check the saw over, which they did. I have been using the saw a lot the last couple of weeks and find dust in the carb each time I check. The o-ring is in place, the filter is snapped together tightly and pushed firmly into place. I find dust inside the filter directly opposite where it fits onto the carb, almost like it came from there.

I probably should take it back, but I have scored a large amount of cherry and oak tree tops that need removed quickly. With three of us getting it after work, it is first-come, first-served.

Can you post some picts of the air filter attached, air filter off, and air filter seperated? That way we can help diagnose where the dust is truly entering.

Brett

 

[NWPA Tim]

I can post pics, but as I have been thinking more about it, I have a theory:

When I pop the entire filter out of the saw and turn it over and look into the opening where it slides onto the carb, there is a round pattern of fine dust straight in from the hole. After separating the two halves of the filter, I find that the rest of the inside is pretty clean.

I believe air is leaking by the o-ring or the black plasting collar the o-ring seats into. This air hits the opposite inside part of the filter and leaves dust there.

I will try to get some pics later today.