Chainsaw Rebuilder?

  • Thread starter Thread starter Bodean
  • Start date Start date
  • Replies Replies 101
  • Views Views 11K
woodworkingboy said:
020 saws had both Walbro and Zama carbs, both adjustable, Walbros on the earlier models. I think you'd hard pressed to find a Walbro speced for that saw now.
Click to expand...

Sorry I met the adjustable main jet. The 020t I have here has a walbro with a fixed main, I'm going to try the 025 carb seeing how they can be had for cheap. I was told the linkages need to be swapped and it will work on the 200t. For $30 I'm willing to try it and see, if it doesn't work I'm out a few bucks and my time. Seeing that the 200t carb fix works and I don't have to buy new ones all the time I am happy either way I have carbs enough here to build lots of 200ts it's the rest of the saw I can't ever seem to have enough of.
 
How long do carb diaphrams last, either with regular use or sitting?

Two saws that are over 10 years old, with a lot of hours are in the shop. I hope its as simple as a carb kit. I had them sitting on my bench for months, waiting to be fixed, but winter didn't provide time.

My 200t, which is a bit sluggish is also about 10 years old.
 
That all depends especially on the fuel. I have saws that are all of 10 years old that I have done nothing to except clean and run them. I'm sure those carbs are not perfect being that old but those saws run just like a new one so I see no reason for a kit. Now with ethanol gas it would not be unheard of to kit one every year. Once they get crunchy they are junk even if there are no holes. Others may have more insight but I'm certainly not one to just throw parts at something for the sake of doing it. To be honest any saw I have ever bought new has never had a kit it's always used ones where somebody ran cheap gas in it. Usually those get torn down and the carbon build up removed anyway so what does a $10 carb kit matter at that point.
 
Those transparent type pump diaphragms seem to last longer than the black ones like used on the metering side. Not sure if the transparent type ever come as original parts on the saw for the pump side, maybe just after market? No ethanol here, but it seems like the black diaphragms seem to start hardening up after three or four years, usually still usable though. I've been buying carb rebuild kits on eBay out of China. Five or six bucks and free international shipping. A kit from a dealer here runs at least thirty to forty bucks, and they can somehow sell them with a straight face. The Chinese ones seem perfectly good, and there are some sellers that give conscientious service.
 
It's funny here you go to an authorized stihl dealer and they give you a cheap Chinese kit and like you say it's $30. You can get on eBay and get a genuine walbro kit for $10-15. The big problem is when you need a kit they are not always found for cheap, the day you get it installed they are everywhere for next to nothing.
 
Kits are not the same all the time. Older materials had higher standards and take the fuels we have today.
Ethanol is not a big problem for membranes. Its all the other crap..

These plastic pump membranes are very different from the ones made from normal material. You feel and hear difference in the saw using these.
When I started out plastic pump membranes was not used much and you got both in the kit. So testing was a must....

If I find a old saw that has not had fuel after '75 I don't need to change membranes. They are just fine 9 times out of 10.

Kits are always available from mfg and the parts distributes.

The cheap stuff I can't say I had good luck with. Wrong pin lever heights, not correct sizes and holes. Stretch fast.. Not the performance I need and they don't last very long. I try to get from mfg. Its no bulletproof stuff either, but chances are higher they are ok...
 
I usually just use the basic kits which only contain the soft components.Tillotson and Walbro are easy to reference but Zama you have to have every number correct to get the right kit .

The newer kits often have a mylar or some other type plastic parts that are either black or clear which I assume to be more robust with ethanol type gasoline. I've yet to see any difference with the main pump diaphragms as they appear to be the standard buna-n impregnated cloth types that have been used for decades .I try to use OEM replacements which I have better luck with .The generics will work but usually fail within a year or two .
I've also observed OEM Stihl seals change from a black buna-n types to a bluish color which I assume also to be more robust .
 
Seems like bad crank seals are at the root of most older pro saws actin up IME.

Got an old MS440 that wouldn't do right after a piston n pot, carb rebuild etc.

Luckily it was a bent compression relief valve responsible for the low comp, and bad crank seals responsible for its refusal to idle down.

Forty bucks worth of crank seals later, she idles n revs up instantly, like an open class desert bike on the pipe.

Gonna give it back to my buddy in the firewood biz with a bow on top sayin high octane no ethanol fuel only please.

Very powerful saws from a power to weight perspective. Not much heavier than my 365 Specials, and a lot more power.

Outta the saw graveyard for forty bucks!
 

Attachments

  • image.jpg
    image.jpg
    150.9 KB · Views: 21
My 440 was acting too, low power, irregular idle. Suddenly the saw jammed during a cut with a big "clac". Piece of steel in the wood ? No, the chain was fine.
She started again after that and finished the cut but can't no more idle at all.
Add at that a metallic rattle noise : a screw in the muffler choose this moment to go away (I didn't found it back). That didn't help for the diagnostic !
It turned out that she had a big air leak due to a bad bearing on the flywheel side. The plastic spacer holding the balls just disappeared. It looks like the balls collected on one side and the flywheel hit the ignition coil. The crankshaft seal, already tired, didn't appreciate the joke.

I put two new bearings and new seals. I'm happy, my saw had fully recovered and run well.
 
There's something about 44's that demands caution and diligent respect.

It's in that power range that'll bite back hard.

I'm rarely if ever in that big a rush to cut as fast as possible anymore.

365's nice n steady keep me alive into old age.

44's are like dragsters tuned just right.

Jomo
 
Thanks Bode, there's somethin comfortin bout old saws that don't have no stinkin microprocessors!

Jomo
 
^^^^ for real!

I helped with a basic chainsaw operators course last weekend.
Two brand new 362C's (Stihl) Stihl dealer gives the emergency services two new ones every year for training.

So, one lady had a little trouble starting it, not unusual you all know how much shoulder throw it takes to start a saw, even with the decomp button. As she was working after a few cuts I'd get her to stop the saw, we'd chat then she'd start it again, to get her used to the action needed. She was getting better as time went on.
Then twice, she'd stopped the saw, we chatted, went to start it again and she couldn't get it to go, I tried and even I couldn't start it. We let it sit for a while, then it would start, needed a very snappy pull though.
I wondered if they had been broken in properly to 'educate' the auto tune???

Then the other group were practicing bore cuts...lot of kickback trying the horizontal bore...chain was all loose. They couldn't tighten it properly, tried the other saw, after a while same thing...loose chain.
I took the saw apart at lunch and voila the chain tension mechanism was BENT on both saws.
So either the force of trying to bore cut and the kickback bent it or someone had tried to tighten the chain with the side nuts done up too tight...

Two brand new saw...buggered...a training saw shouldn't be that precious that a bit of novice handling renders it inoperable!!
 
  • Thread Starter Thread Starter
  • #64
So yeah... on my way.

I replaced the pin, lever and rod and gaskets on the metering side...went well.

The other side the pump side going well.

Just not sure about the circle gasket and where that goes?

6c20ad45a058c6fce040afced875520c.jpg
 
  • Thread Starter Thread Starter
  • #66
Now. After putting everything back together it only coughs with the choke.

The same kinda problem....though seems like after I replaced fuel line and before carb "rebuild" I could keep it going with revs but wouldn't idle.

Now, I do not realize my error.

:)
 
With my 044, I had a tank vent that was a screw type. Its the hose that just terminates at the filter housing. Left side of the carb.
I opened that up (lefty loosie) about 1/2 turn at a time and it came alive. Make sure you put a new impulse hose in as well. Runs from the head to the carb or intake the carb seats to, I forget.
 
Bermy said:
^^^^ for real!

I helped with a basic chainsaw operators course last weekend.
Two brand new 362C's (Stihl) Stihl dealer gives the emergency services two new ones every year for training.

So, one lady had a little trouble starting it, not unusual you all know how much shoulder throw it takes to start a saw, even with the decomp button. As she was working after a few cuts I'd get her to stop the saw, we'd chat then she'd start it again, to get her used to the action needed. She was getting better as time went on.
Then twice, she'd stopped the saw, we chatted, went to start it again and she couldn't get it to go, I tried and even I couldn't start it. We let it sit for a while, then it would start, needed a very snappy pull though.
I wondered if they had been broken in properly to 'educate' the auto tune???

Then the other group were practicing bore cuts...lot of kickback trying the horizontal bore...chain was all loose. They couldn't tighten it properly, tried the other saw, after a while same thing...loose chain.
I took the saw apart at lunch and voila the chain tension mechanism was BENT on both saws.
So either the force of trying to bore cut and the kickback bent it or someone had tried to tighten the chain with the side nuts done up too tight...

Two brand new saw...buggered...a training saw shouldn't be that precious that a bit of novice handling renders it inoperable!!
Click to expand...
Auto tune saws can take a hell of a battering with trainees.
The one that is hard to start - gap the coil & the plug accurately then try again (the auto tune presumes they are spot on). If the coil gap is too small it will effectively advance the timing making it practically impossible to pull over.
I have seen a couple of chain tensioner fail - I broke one being too rough trying to free a stuck saw. I have also seen them damaged though over tightening or tightening without freeing the bar nuts off enough.
I will look up how to reset the auto tune if you need - can't remember it perfectly off the top of my head
 
Deva, are you sure that you have the gaskets and diaphragms in the right order? The metering side has the gasket next to the carb body under the diaphragm. When you take off the cap you only see the diaphragm. The pump side the diaphragm is next to the carb body with the gasket on top under the cap, i.e. it's the opposite from the metering side.
 
  • Thread Starter Thread Starter
  • #71
Yeah. Jay. They are as you described. The pumpside has the gasket under the cap with the screen in t he middle with the other rubber piece to the carb.

Stephen. I'm still looking for that head hose. The breather I opened and cleaned, nothing in there.
 
Impulse line's at the bottom of the carb, fuel line's on the left side.

Bad impulse line would starve the carb's ability to draw in sufficient fuel.

Jomo
 
You must log in or register to reply here.

Similar threads

lxskllr
Chipper 101
7 8 9
Replies
213
Views
8K
BlackSmith
BlackSmith
Intact
Ported 590 not starting, BADLY want to fix at-home!
Replies
4
Views
949
Nutball
Nutball
Jomo
Meticulous Chainsaw Maintenance
2
Replies
44
Views
3K
stig
stig
ruel
066 rebuild no start
2
Replies
35
Views
3K
Magnus
Magnus
flatlinesup
Milwaukee M18 Saw (and forum intro)
Replies
22
Views
3K
chainsawer4741
C
Back
Top