varied 395xp questions

I've been searching and reading and trying to get a handle on this. lots of good information out there on this site--these forums. (I particularly found the 3 percent per 1000 feet change in elevation rule of thumb interesting in regards to power and also compression readings, but I'm rambling now)

Bottom line, a new Husky 395 that was initially tuned at sea level but has made it's way to 9000 feet in elevation.

As we know the darn thing is limited in how far it can be tuned by the EPA caps in the tuning screws on the Carburetor.


My understanding is that it's limited to keep us from running our saws too rich and thus adding un-needed pollution to the air. But in this case, the limiting keeps the saw from being able to get leaned out enough. (I wish it had those little plastic limiters, I'd take a razor blade, scalpel, dremel tool or something to modify them)

I really haven't looked too close at the carb, but from what I can see it seems they have made if very difficult to modify the limiters.



(Running 92 octane with 50:1 Stihl or Husky oil) Factory setting it would only run at 9200 rpms WOT--- leaned out all the way to where the limiter stops the H screw-- it makes it up to 10,500 on a 32 degree F not very humid day. Max is 12,500

Now I don't want to lean it out all the way to max RPM, but it seems to me this is a bit of a waste only being able to get to 10,500.
I suppose I should look closer at the screws on that Walbro and see if I can get them apart and modified without causing any damage.

I guess my question really is though (and I haven't even measured the size of the exhaust port in comparison to the hole in the muffler) -- If I muffler modded it, do you think it would, it could; improve air flow enough to compensate for the limited high tuning this saw has ? (I'm thinking more air, same amount of gas should create a 'leaner' running saw-- feel free to set me straight if I'm grossly mis-understanding this)

a picture with a quarter laid on top of the factory spark arresting screen



It does seem a little bit limited behind that screen too, the pipe leading up to the screen is only the diameter of a dime or slightly larger but I can't get a good picture of that.

anyone have experience with the new Walbro carburetors? or experience in muffler modifications for this particular model?
carb picture




the muffler


apologies if I'm :deadhorse:

No experience with that particular model, and I can't make out the limiters in your pics. Hopefully another 395 owner will come along and shed light on it.

A muffler mod is always a good idea, and yes, that'll lean it out a bit, which should work to your advantage.

Assuming you get eventually get it tuned satisfactorily, power is still going to blow at 9000 feet. Nothing you can do about it.

mtngun said:

No experience with that particular model, and I can't make out the limiters in your pics. Hopefully another 395 owner will come along and shed light on it.

A muffler mod is always a good idea, and yes, that'll lean it out a bit, which should work to your advantage.

Assuming you get eventually get it tuned satisfactorily, power is still going to blow at 9000 feet. Nothing you can do about it.

Click to expand...

Thanks for the reply mtngun

It may not be as powerful as at a lower elevation, but all things relative it sure seems a step up from the 288, which was a step up from the 272.

And the H and L adjustments all you can see is the screw head-- the limiters are somewhere buried inside of the metal of the carburetor body.

here's a little blurb from walbro about this model carb.

http://walbro.com/techtips2.aspx

newmexico said:

Thanks for the reply mtngun

It may not be as powerful as at a lower elevation, but all things relative it sure seems a step up from the 288, which was a step up from the 272.

And the H and L adjustments all you can see is the screw head-- the limiters are somewhere buried inside of the metal of the carburetor body.

here's a little blurb from walbro about this model carb.

http://walbro.com/techtips2.aspx

Click to expand...

Head to your local small engine shop where they know you by name.
Have them order the proper adjustment tool for ya.

They are also available on E-bay if you don't mind searching and then dealing with all that mess to order one.

There is no getting around it, you're gonna have to properly tune that 395 for elevation. When I opened up the Muffler on my 395, the low needle needed to be adjusted more than the high.

There is a BIG difference in grunt between running Fat just out of 4 stroking in the cut, and running just a little fat and lightly 4stroking out of the cut, with the 395. Running rich also leads to carbon build up that flakes off and can hang a ring as well.

Good luck to ya!

Stay safe!
Dingeryote

You will need to pull the needle's out of the carb to trim the limiter tabs off. Much easier.

dingeryote said:

Head to your local small engine shop where they know you by name.
Have them order the proper adjustment tool for ya.

They are also available on E-bay if you don't mind searching and then dealing with all that mess to order one.

There is no getting around it, you're gonna have to properly tune that 395 for elevation. When I opened up the Muffler on my 395, the low needle needed to be adjusted more than the high.

There is a BIG difference in grunt between running Fat just out of 4 stroking in the cut, and running just a little fat and lightly 4stroking out of the cut, with the 395. Running rich also leads to carbon build up that flakes off and can hang a ring as well.

Good luck to ya!

Stay safe!
Dingeryote

Click to expand...

Dito on the L-jet, my 394xpgw needed more on L-jet then the H-jet after the muffler mod

Hi NEWMEXICO;

If yours has the Tillotson carb, there should be a plastic shoud around the needles, do not try to pry the whole shroud (the needle springs are inside the shoud). At the top of this shroud is an plastic insert that covers the needle tips except a small hole for the screw-driver.

Take a small screwdriver (2.0 mm or smaller, and pry the insert piece up, it shoud pry up and then remove the insert piece. This should leave the shroud open and you can then see the tabs that are on the H/L needles.

Next take a dremel with a very small round cutter for plastic and machine off the tabs on each needle, be very careful as this space is tiny to work in. Now you can adjust your carb.

If you carb is a Walbro the above will not work.

Miles86 said:

Hi NEWMEXICO;

If yours has the Tillotson carb, there should be a plastic shoud around the needles, do not try to pry the whole shroud (the needle springs are inside the shoud). At the top of this shroud is an plastic insert that covers the needle tips except a small hole for the screw-driver.

Take a small screwdriver (2.0 mm or smaller, and pry the insert piece up, it shoud pry up and then remove the insert piece. This should leave the shroud open and you can then see the tabs that are on the H/L needles.

Next take a dremel with a very small round cutter for plastic and machine off the tabs on each needle, be very careful as this space is tiny to work in. Now you can adjust your carb.

If you carb is a Walbro the above will not work.

Click to expand...

I wish it were a Tillotson...

_________________________________________________________________________________________________________________________________________________________________

parrisw said:

You will need to pull the needle's out of the carb to trim the limiter tabs off. Much easier.

Click to expand...

Do you mean opening up the carb and pulling them out from the inside of the carb or can you pull them from the outside? Here's a better picture of them. The whole inside round ring with the little serrations on it spins as I turn the screws.



___________________________________________________________________________________________________________________________________________________________________


I'm thinking maybe, because I'm not really all that mechanically inclined, I may end up taking it to a good small engine repair guy around here and avoid tearing something up. That said, I still would like to figure it out 'cause I'm a little stubborn like that.

_____________________________________________________________________________________________________________________________________________________________________________

It is a Walbro with the part #WJ115 902 stamped into it for what that's worth.

and just cause I can now see into the intake here's a picture of that.








and jeesh, looking at the preview of this post I now know in the future I'm going to break posts up into more manageable, readable snips (and yes one of these days I'll also figure out how to make this silly pictures appear in the reply without you having to click on them. ((edited--it's now figured out ))
Thanks again all of ya'll for your expertise.. I am a :newbie: and appreciate it.

test

Just figured it out finally



and looking a little closer at the I see that the little round metal sheaths around the needle screws can be depressed and have a little notch in them.

(wondering if I can fabricate a tool of some kind to depress to a point where they turn independent of the needle screw, and find a place where they are free to then slide out under the spring tension... then reinsert at a more tune-worthy rotation.

Thanks for the detailed pic, I'll file that away in my memory in case I ever get a 395.

You can take a tiny screwdriver and push the limiter in and turn the screw and then let up and it will stay.

little update

((((((((((EDITED to say +1 to what mdavlee said up there^^^^^)))))))))))


Ok.. so what I did was take the H needle turn it to it's richest setting (which is where it was from the factory).

Then using two toothpicks to gingerly,fully depress the sleeve around the needle jet screws and while I had it depressed turned the needle jet screw 1/4 turn towards lean...
It appears from just looking at it to have given me a little more leeway in leaning out the saw.



I fiddled for a little bit with some .223 brass as it's very close in diameter at the neck to the sleeve around the needle jet.
Leaving a small tab on the brass that fit into groove on the sleeve and trying to turn the sleeve thinking that the sleeve might turn while the needle screw remained stationary.



But, it appears that when depressed the sleeve doesn't want to turn even when I did manage to get the little tab to fit into the little slot.


In depressing the sleeve with toothpicks and turning the needle with a tuning screwdriver the sleeve also didn't turn while the needle jet screw turned freely..
this though,may have been attributable to the toothpicks creating friction between the carb housing and the sleeve.


I'm thinking a tube open at both ends with a little tab to make sure the sleeve won't spin and a longish screwdriver to turn the needle jet screw while using the tube to depress the sleeve might just work while the saw is all in one piece..



Now to put the saw back together and test this theory... bur first must make tool that allows me to do this adjustment with saw together-- New Husky is work to get apart---- I guess I'll get better at it as time goes on though.

just to figure that out

Had to go this far--



but all in all not too bad, I learnt somethin --all the pieces were back together and it was running again in less than 20 minutes-- I'll see tomorrow if the adjustment actually changed anything.

New Mexico,

The tool for adjusting that carb cost me 7 bucks at the local hardware/OPE shop.

Get one and save yourself going nuts.
They work great!

Stay safe!
Dingeryote

dingeryote said:

New Mexico,

The tool for adjusting that carb cost me 7 bucks at the local hardware/OPE shop.

Get one and save yourself going nuts.
They work great!

Stay safe!
Dingeryote

Click to expand...

:agree2:

think I found one now that I know what I'm looking for, bet it looks something like this..

newmexico said:

:agree2:

think I found one now that I know what I'm looking for, bet it looks something like this..

Click to expand...

Yep!

I bought one after tearing things down and deciding it was gonna be a PITA to not just use the proper tool. LOL!!

Works great.

Stay safe!
Dingeryote

dingeryote said:

Yep!

I bought one after tearing things down and deciding it was gonna be a PITA to not just use the proper tool. LOL!!

Works great.

Stay safe!
Dingeryote

Click to expand...

With this tool, does it limit how much you can turn the screws?

It's purely curiosity on my part. I have an older 395xp and the plastic EPA things they put on the screws were easily removed. This looks more troublesome.

rayvil01 said:

With this tool, does it limit how much you can turn the screws?

It's purely curiosity on my part. I have an older 395xp and the plastic EPA things they put on the screws were easily removed. This looks more troublesome.

Click to expand...

The driver is supposed to be a limited access item..wink, wink.
No limits, just the tool.

Stay safe!
Dingeryote

they sell em on the internet

I think if you oogle Genuine Poulan Weedeater Part # 530035560 you'll get this http://www.google.com/search?client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&channel=s&hl=en&source=hp&q=Genuine+Poulan+Weedeater+Part+%23+530035560&btnG=Google+Search

which is probably the right one.

I just got back from the local stihl dealer where I went to the parts counter and asked for a "carb adjusting tool that looks like a nutdriver but has spines inside and -- wahlaa six dollars and forty cents later I had the proper tool.

actually it's a really good design, once it's over the needle screw and pressing the sleeve down there's no slipping off, very positive grip that allows for fine tuning.

after oogling again I found this short thread from this site that has a little more info on the tool.


http://www.arboristsite.com/showthread.php?t=131781

am I really reading this???????