stripped carb limiter...is that a problem?

[JamesJems]

New guy here. I've been lurking around here for a week or so trying to figure out what to do with my new MS260. Yesterday I decided to modify the muffler and so I drilled a couple of holes...

Then tried to adjust the carb (H-screw). Wound up stripping the red plastic thing with a drywall screw. But I did manage to turn the H-screw a little to the left (CCW) to make it a bit richer. ( I don't have a tach, but I do have a local saw shop).

Just how important is that little red plastic limiter screw? Was it installed just to keep pesky little fingers like mine from fiddling with it, or will the H-screw actaully come out of adjustment without it?

Oh, and ah...is it possible to be more precise with the H-screw mixture adjustment *without* a tachometer?

James

 

[Ekka]

As long as the H and L screws dont turn to easily and vibrate to a different position ... who cares.

Just another gimmick to make it look like we care about the planet, pollution and idiots who cant tune a saw.

Yeah the last ones important coz some wanker would think "geee i can get heaps more revs by turning this here thingy in a bit", then 2 days later he's trying out a warranty claim.

Madsens site had a couple of wav sound files to demo what it should sound like but their website is down.

http://www.madsens1.com/sawtune.htm

A tach is the best but I have never used one in 10 years to set a saw coz I dont own a saw tach. But I got 2 good ears.

When the saw's warm I hold the trigger flat chat, screw in very slowly till the revs increase ... now that means it's getting lean.

Then I come back out about 1/4 turn. The saw runs just off peak, a sort of blubbering or just missing and heaven forbid I call it 4 stroking. Then try it in some wood.

I had the same thing with my 025 when I took the screen out and opened up the muffler. You have to richen about 1/2 turn, get that blubbering sound.

And you can see by the condition of my old saws pistons and pots that engine wear is minimzed. I run 32:1 stihl 2 stroke oil also and swear by it. I did try that Husky oil and dont like it, but Shindaiwa 2 stroke oil is good to, the guy said is the same as stihl (synthetic)

 

[Lakeside53]

You need the cap to stop the H screw from moving. It has no spring on it and the rubber washer doesn't hold it in postion. I assume you have a WTE carb with a limiter only on the H screw?

They are bi?ch to get off without the correct left-hand threaded tool. You used a drywall screw which is right hand threaded - if you do this, you need to move the limiter cap fully CCW until the tab lines up with the exit slot, then withdraw.

Buy a new cap (50 cents or less), dig out the old cap (chuck it), slice the side tab off the new cap and pop it back in.


The MS260 tunes pretty good by ear, but a mangled cap is going to make it hard to do. A tach is good check - 14k is the max Rpm allowed.

 

[Lakeside53]

but Shindaiwa 2 stroke oil is good to, the guy said is the same as stihl (synthetic)

It might be in Aus, but not in the USA.

 

[Kneejerk Bombas]

Buy a new cap (50 cents or less), dig out the old cap, slice the side tab off the old one and pop it back in.

I would slice the tab off the new cap and throw the old one away!

 

[Lakeside53]

I would slice the tab off the new cap and throw the old one away!

see, somebody does read my posts...

I'll fix that!!!

 

[Ekka]

Yeah and now the manufacturers have read these posts and gonna make some newfangled BS that'll stuff us up.

Things were so simple once.

 

[MAG58]

Limiter Caps

Have posted this before, It's no need to ground off the plastic ears on the limiter caps, or destroy them in any way. Just flip them out a bit, then us a screwdriver that go into the hole in the caps and you can turn the metal screws.

 

[Lakeside53]

Have posted this before, It's no need to ground off the plastic ears on the limiter caps, or destroy them in any way. Just flip them out a bit, then us a screwdriver that go into the hole in the caps and you can turn the metal screws.

Maybe so... what that won't work on a walbro carb on a Stihl!

 

[MAG58]

Maybe so... what that won't work on a walbro carb on a Stihl!

On Husky and Jred's it's work good :greenchainsaw:

 

[JamesJems]

I assume you have a WTE carb with a limiter only on the H screw?

yea, Lakeside, it's a WTE carb, (whatever that is...) the red limiter is only on the H-screw. I defaced it pretty good getting to the limiter. The drywall screw stripped it, but it never pulled it out completely. How do I dig the rest out??? I just KNOW I'm gonna mess something up...I mean, is it easier if I take the carb off? I don't know how to do that.

Shoot.

You guys are a big help. Ekka, thanks for the perfect description of how to tune by ear. I can't wait for the Madsen's site to come back on line.

James

 

[Lakeside53]

It's a real pain .. you mess them up and... I end up spending 30 minutes getting them out, and when you get the bill You're not the only one that's done this - which is why I don't push the drywall screw idea....

It might be easier with the carb off ... but...

Try using a small but HIGH QUALITY flat bladed screw driver... push it down though the old limiter cap and then while maintaining a decent inward pressure, unscrew the actual needle valve - lots of turns as it has a very fine thread. If you are lucky, it will jack the old cap out. If not, you'll have more room to pick out the pieces. Don't blow air into the old cavity without the needle valve in place or you'll pack junk into the carb.


If you need to take the carb off, turn the saw upside down and remove the screws holding the handle top onto the tank. Then remove the two nuts on the carb studs, the linkage, the fuel line (careful... plug it or drain the tank!). It will then slide off the studs.

 

[Reddog]

My dealer and I don't agree with lake on this. Take it off and leave it off. The rubber holds it fine. I've got three saws this way and have no problems with them moving. But I check my saws every day. But its your saw do what you want.

 

[Lakeside53]

My dealer and I don't agree with lake on this. Take it off and leave it off. The rubber holds it fine. I've got three saws this way and have no problems with them moving. But I check my saws every day. But its your saw do what you want.

I don't need to check my saws every day - I know they are where I set them last. Your dealer should talk to the carb manufacturer....

The rubber is just a dirt seal. It only sits on a very small part of the adjustment range, and depending on the carb and who last removed the screws and replaced them (without resetting the rubber postion), can easily be on the wrong portion of the thread to even do that.

I've watched them rotate, particularly on blowers when I'm just trying to set them up. Luckily they tend to unscrew rather than lean out, but they sure can move.

Yep, it's your saw - do whatever you want! For 50c, I know what I'd do.

 

[Reddog]

I don't need to check my saws every day - I know they are where I set them last. Your dealer should talk to the carb manufacturer....

The rubber is just a dirt seal. It only sits on a very small part of the adjustment range, and depending on the carb and who last removed the screws and replaced them (without resetting the rubber postion), can easily be on the wrong portion of the thread to even do that.

I've watched them rotate, particularly on blowers when I'm just trying to set them up. Luckily they tend to unscrew rather than lean out, but they sure can move.

Yep, it's your saw - do whatever you want! For 50c, I know what I'd do.

Yea and it's fun to get your talk every time.

 

[Lakeside53]

Yea and it's fun to get your talk every time.

Likewise!