Rebuilding stihl 044

[Mike Whitmore]

Matt olson put red loctite on the crank for sealing the spacer

 

[Mike Whitmore]

I replaced the impulse line....and then when i had the leak...i checked just the impules line itself since that is where im injecting pressure and vacuum from..

By the way i found a really great way to make sealers for the carb and exhaust ports..when vacuum testing.....i had a sheet of 5/15 acrylic. From where i was fabricating something...and i have a koi pond...nice epdm (rubber) liner material..cut a couple pieces to fit drilled to match bolt patterns in acrylic, then doubled the epdm up cut small holes for screws in epdm. And presto...nice seals for pressure and vacuum testing. I was gonna make some outta 1/8 inch sheet steel..but acrylic much easier to cut and shape.

 

[drf255]

Without the clutch torqued down, that spacer will leak a bit. Don’t use loctite, use some grease. Like Buck said, the O ring’s necessity is debatable.

If it’s idling fine, I doubt it has an air leak.

1128 series Stihl (044/046/461) use either a Zama or Walbro Carb. Different kits, so make sure which one you have on the saw.

The HD will have the carb number stamped on the side of the body, the Zama with have it cast on the side. I believe the Zama is a C3A, but I could be wrong on that.

Watch the way you put the diaphragms on and pressure test the carb once you have the pump side clamped down and before the metering diaphragm/gasket/plate is installed. Wear safety glasses and wet the needle and seat with a few drops of mix before you test it. We can walk you through that testing.

Start with the needles 1 turn out each from a light seating. Tune from there.

You’ll get it.

 

[Mike Whitmore]

Well i think i found the issue..if i tighten the clutch down with the case under pressure, you can hear the pressure escape....then with clutch tight it wont hold pressure....that is with grease.....i dont know what to do....also it wasnt red loctite..it was anaerobic sealer im thinking about trying that....i put grease inside spacer, and on the shaft...even tried packing grease inside of oiler and put in oiler plastic piece with hook....gonna see what you think before i do anything else....its about to get a sledgehammer

 

[BuckthornBonnie]

Pics?

It’s possible that the crank is worn, the spacer itself is worn, or the bearing recess is wallowed out in the case.

 

[Mike Whitmore]

Holy ****...i just found it....look at this ****..reason it blew up too i bet... that is the spacer up close...almost impossible to see.. you can see where the oring that was on this spacer wore out completely...also why when i tightened clutch down it leaked, because it made the crack spread

 

[BuckthornBonnie]

Bingo

 

[Mike Whitmore]

Some pics


Some pics of the pressure testing jigs...used sockets for spacers..the bottom piece of acrylic on the carb side is full coverage..just used a piece for spacing on top

Also the bearing spacer in normal size...and the crack is facing the camera...if you zoom in on the pic you can barely make out the slightest hint of a line..the crack is in the top of the shine nearest my hand side
Also since i found this problem it appears that at least 4 or 5 others had same issue posted on other sites.

 

[drf255]

I’ve had one that was cracked in half. It fell apart into two pieces upon removal to check the seal. Good catch.

 

[Mike Whitmore]

Got new spacer bushing. Greased it up greased shaft put it on, put washer and clutch on...and a tiniest bit of pressure loss...i took clutch off, set saw level, pressed down on spacer with finger...and put soapy water. And i have these tiny little air bubbles coming out of that bushing between the spacer and the crank...its less bubbles that a foan starts to expand around the top of that spacer bushing against the crank....it takes about a minute to drop from 7 to 6 pounds....what a pos design...why the hell didnt they thicken the crank further...not sure what to do now

 

[Mike Whitmore]

Gonna wait for ideas..right now im thinking about using anaerobic sealer inside spacer bushing...On new replacement 440 crank it looks like the crank is thickened....but that is for 12mm wrist pin..mine is 10mm

 

[Mike Whitmore]

Also which zama c3m carb is this?

 

[Mike Whitmore]

Ok zama c3m s5g...rebuild kit rb-36..do i need a metering tool?

 

[Mike Whitmore]

Put it together ran alright seemed to bog at more throttle...maybe flooding...i ordered rb 36..watched rebuild video..seems easy enuf..

 

[president]

Got new spacer bushing. Greased it up greased shaft put it on, put washer and clutch on...and a tiniest bit of pressure loss...i took clutch off, set saw level, pressed down on spacer with finger...and put soapy water. And i have these tiny little air bubbles coming out of that bushing between the spacer and the crank...its less bubbles that a foan starts to expand around the top of that spacer bushing against the crank....it takes about a minute to drop from 7 to 6 pounds....what a pos design...why the hell didnt they thicken the crank further...not sure what to do now

372 huskys used the same goofy setup too

 

[president]

Gonna wait for ideas..right now im thinking about using anaerobic sealer inside spacer bushing...On new replacement 440 crank it looks like the crank is thickened....but that is for 12mm wrist pin..mine is 10mm

I have the latter ms 440 and there is no recess for the 0 ring in the outside surface
it appears to fit inside the belled flare ,mabey it has been updated and not prone to split

 

[bayard]

does the clutch go on clockwise?

 

[president]

does the clutch go on clockwise?

no, spins on anti clockwise

 

[scallywag]

Gonna wait for ideas..right now im thinking about using anaerobic sealer inside spacer bushing..

Perhaps something like MotoSeal or ThreeBond in place of where the early 044's had the O-ring?......Be sure to check the temperature rating of any sealant you choose to use in this area.

 

[BuckthornBonnie]

Ok zama c3m s5g...rebuild kit rb-36..do i need a metering tool?

Usually not... check level before removing screw/needle. Avoid aftermarket springs.