Wet air filter problem

Ax-Man

Ax-Man

Don't make me chop you
Joined
Feb 4, 2006
Messages
705
Location
N.E. Illinois
I have two pieces of equipment suffering from this problem. One is HT 101 and the other one that just showed up today in an older 020 AVP beater saw. Both pieces do fine till the air filters get wet from too much mix then they start to run doggy or just won't start which is what happens with the 101.

Is this a carb problem or a ring to cylinder wall problem ???

To me it isn't a carb problem because I can take out the air filter and they run and start like they are suppose too.

But on another note I have saws that I know that the top end is not as good as these two pieces but don't suffer from this wet air filter problem even after getting run hard and for a long period of time.

Anyone ever run across this particular problem.
 
Too much back pressure through the carb. It's blowing the fuel mix back into the air filter. This is why the 200T has the piece of sponge under the air filter below the throat opening. It catches blowback fuel and holds it until it gets sucked back into the motor again. reducing the amount that can soak the air filter.

I'd look at opening the muffler slightly and/or checking to see if the carb is adjusted too rich.
 
  • Thread Starter Thread Starter
  • #4
Leak??? From where.

To me it is like the mix is getting past the rings on the down stroke of the piston before the transfers open. Kind of like blow by in a four stroke. I don't lnow if that possible in a two stroke or not.
 
By the very nature and design of the engine you will have a little bit of back blow.It can't be helped . Lean it up a RCH and see what that does .

I suppose you could have some muffler restrictions also .If it can't get out then it can't draw down as hard on the transfers .Which means it can't draw down as hard on the intake .
 
  • Thread Starter Thread Starter
  • #6
I'll go along with that Brian.

I hate to tinker anymore with that 101. I have that thing dialed in to where it starts on the first pull as long the filter is dry. The muffler on that has been opened a little. The 020, I don't know, the muffler could be carboned up as I have had that saw a long time. That darn thing was always a finicky saw but this past winter I swapped out the carb on that one for a carb that was like new and that solved the finickyness in it. Runs better than when it was a full time work saw. It was a top handle 020 but I made it into a rearhandled sort of like a back-up for our ms 200 rear handle.
 
Along the lines of what Skwerl WISELY posted, you might take off the muffler and look for carbon buildup around the exhaust port.

Leaking...don't know the arrangement on those saws, but was thinking it could be coming from a bad fuel tank breather, if in the vicinity.
 
  • Thread Starter Thread Starter
  • #13
Sorry Top , I never get rid of any either 020 or ms 200's :P

You know Wood now that I think about it I have run into a few two strokes that the venting for the gas tank was tied into the air filter housing. I can't remember what they were though.
 
It also has a lot to do with how the filter is made . If it was a wire mesh filter it wouldn't do a thing blowing fuel . Some of the celulous fiber filters would just plug up tight as a bulls butt at fly time . After enough of the surface of the filter got wet it would be about like running with the choke on .
 
  • Thread Starter Thread Starter
  • #15
That is exactly what is happening. Al, just like the choke is on and then giving it full throttle.

I'll see if a little leaner setting helps. It is just aggrevating more than anything. No compressor out on the job to blow dry the filter. :cry:

That 101 has a real thick filter like a blower. You wouldn't know that one was soaked with mix till it just got so saturated it would drip out of the filter. Now that is bad. After I finally figured out what was happening out on the job I just ran it without a filter just to finish up till I could get it back to the shop. I need an excuse to buy a new one if I could afford it that is.

Good old Sthil, gotta love em. :lol:
 
Strange problem. It's hard to picture an engine running so rich that the filter drips fuel, and at the same time the engine is running good until the filter gets saturated, and runs good without the filter. I'd think that with so much fuel getting excluded from the cylinder, you'd have a lean situation happening.

I think I'd be wanting to overhaul the carb first thing.
 
I'm just about ready to trot off to the woods to cut up some pecker poles .I'll take a peek inside my 200 to see if there might be some gizmo like a piece of sponge stuck in the filter to attempt to prevent this problem .

I've never experienced this problem so I really never paid attention to the filter .
 
Well I got my skinny trees cut up .Not a big deal just some clean up stuff I do every couple of years .

Any who the 020T lists two air filters .One is evidently some type paper and the other is a felt material . In addition as B pointed out there is also a foam insert that sits in a little pocket in the filter housing .Mine is missing .

I would venture a guess the felt might be better at aleviating that wet filter business .The number is 1129-120-1606 .I also imagine a chunk of closed cell foam would work as well as the original foam insert .It's worth a try at least but the replacement probabley isn't that much .
 
I don't think the foam thing is for filtering the air but rather to catch the fuel spray .

Perhaps closed cell is not really what I should have said but it has to be some material that won't flake off and get sucked into the engine . I don't think a synthetic sponge would be the best choice .
 
I have an old Stihl boat anchor that's filter is entirely a thin piece of synthetic foam. No problems that I've noticed.
 
You must log in or register to reply here.

Similar threads

Intact
Ported 590 not starting, BADLY want to fix at-home!
Replies
4
Views
701
Nutball
Nutball
ruel
066 rebuild no start
2
Replies
35
Views
2K
Magnus
Magnus
flatlinesup
Milwaukee M18 Saw (and forum intro)
Replies
22
Views
2K
chainsawer4741
C
ruel
066 parts
Replies
4
Views
1K
Cut4fun
Cut4fun
Nutball
Ported Echo 2511t Raffle!
4 5 6
Replies
141
Views
17K
lxskllr
lxskllr
Back
Top