Another 044 rebuild

[ENTS]

Bought a VERY USED 044 the other day.  Starting stripping it down and relpacing broken parts.  Seems it was droppedl (from a great distance) or something was dropped on it.  Both side covers are cracked and the front mount on the rear handle (fuel tank) is cracked in two places.  Have to replace that handle but the side covers will have to do till I can afford to replace them.  The piston looks in great shape.

I decided to tear the carb. apart, put it in the ultrasonic cleaner for an hour and proceeded to put it back together (new kit).  Question about the metering lever height--level with the carb. body or otherwise?  It's a Walbro HD-17A.  I found a picture of the Walbro tool (500-13) for setting the height on the lever.  It has markings for various carbs. but not the HD.  It does have a marking for HDA but not sure it's the same animal.  Can anyone shead some light on this?

Thanks,

[stonebroke]

what kind of ultrasonic cleaner do you have that can do carbs?

Stonebroke

[ENTS]

what kind of ultrasonic cleaner do you have that can do carbs?

Stonebroke

I got it army surplus, holds about 2 gals of water, was next to brand new, got it for peanuts.  I put small parts in the basket and then hang the stripped carb in the bath.  Water gets really hot after an hour.  Everything comes out squeaky clean.  Hung a piston in it once, came out sparkling.

[ENTS]

Found the answer to my metering lever height ques.  It's level with the carb. body.  This HD carb is the same (I'm told by a Stihl tech) height as the HDA carb and they are level with the carb. body.  Next trick is getting it back on the saw.  Looks like you need 4 tiny hands.

Later

[joe_indi]

Next trick is getting it back on the saw.  Looks like you need 4 tiny hands.

Later

Put in the screw that holds the pin first, just by 1 turn.Put a drop of 2stroke oil into the tiny well for the spring.Put the spring into the well.The oil will hold the spring in position.
Another drop of oil on the front of the lever will hold the needle in place.
Slide the pin onto the lever.
Holding the lever between your thumb and 2nd finger, with your 1st finger to steady the lever, move the lever into position so that the needle goes into its well, the spring fits into the tiny cone on the bottom of the lever and the pin is in line wit its groove.
Pressing down gently on the lever, just above the position of the spring, align the pin in its groove and tighten the screw.
If you have a pressure gauge connect it to the fuel inlet.pour  a few drops of oil into the metering well and pump up the pressure to 0.8bar (10psi approx).
There should be no bubbles at the metering needle.
Keep a screwdriver horizontally and move along the top of the metering lever.
The ideal position for a 440/044/046/460 is when you get a very very tiny spurt of air coming out at just one particular position on top of the lever.

[ENTS]

Thanks joe_    That oil trick makes it a lot easier with that squirmy spring.  Buttoned it all up late last night and pressure tested it.  10psi and has a VERY slow leak down.  I need to bring a container of clean water out to the shed and determine where the bubbles are coming from. 

Later,

[ENTS]

Need some carb. guru advice:

The slow leak on this carb is around the cap that covers the fuel pump (not the metering side).  Does the gasket go down dry or use gasket cement  OR does use swell that gasket and it seals?

Another ques.  I located 3 ipls for this carb with 2 showing a fuel pump diaphragm and a gasket with the gasket agaisnt the cover.  The other ipl shows the afore mentioned 2 items PLUS another part marked fuel pump diaphragm.  This is a rubbery material thicker than the other fuel diaphragm and goes agaisnt the carb. body.  Which is correct??

Any help here is appreciated,

Later,

[Rocky_J]

You never want to use gasket cement or sealer on a carb. As far as the additional gasket on the diaphram, I'm guessing that would depend on the carb and diaphram. Minor details like this get changed over the years. I'd recommend simply picking up a new diaphram/gasket kit for the carb from a local dealer.

[joe_indi]

Need some carb. guru advice:

The slow leak on this carb is around the cap that covers the fuel pump (not the metering side).  Does the gasket go down dry or use gasket cement  OR does use swell that gasket and it seals?

Soak the gasket in fuel before you install it.Better still, use a bit of gasoline with some extra oil to soak the gasket.Oil the carb surface and the cover surface.
The gasket goes onto the cover then the diaphragm.
Tighten the screw, apply oil all round the sealing point and pump up the pressure.The point of leak should now show up as a small bit of froth in the oil.If this does not happen, your pump diaphragm seat is okay.If it does show any froth, loosen the centre screw slightly and tap the cover with a small spanner and re tighten the screw.You might have to repeat this a couple of times to get a seat.However, if the gasket itself is damaged there is no other cure than a replacement.
Apply a bit of oil to the impluse pipe on the bottom of the carb and pump up the pressure again if air bubbles are seen at the end of the pipe, you have a damaged pump diaphragm which needs replacement.

[ENTS]

Rocky -- I figured that gasket cement was a no no.  As far as new gasket kit, that's where I find the extra part, in the new kit.  I think I need to go looking thru the garbage to find the old gaskets.  Maybe they will tell me something.  The residue left behind on the carb body make me think there was another piece agaisnt the carb. body.  

[ENTS]

Tried to post a picture of the carb. body/residue but I guess I've forgotten how.  It's up my my gallery tho.

Joe_   I'm a gonna go soak that gasket right after lunch.  Any insight on the third piece?  I'll put pictures up in my gallery after lunch.

Later and thanks,

[joe_indi]

Joe_   I'm a gonna go soak that gasket right after lunch.  Any insight on the third piece?  I'll put pictures up in my gallery after lunch.

No third piece  there, unless its for some B.C. version :D
Just the cover, then the gasket and then the diaphragm, biscuit colored (mylar I think).
Dont bust your head over the 'third part'.
You mentioned some residue.Was it in the cover, in the rectangular shaped area?
If yes, clean it out and make sure that the impulse tube that emerges from there is not blocked.
Lunch eh? I've just had my dinner.

[ENTS]

I think I've figured out my confusion. 

The ipl shows two (2) diaphragms, the kit contains two (2) gaskets (each a different material, rubbery and stiff).  I figured this out after staring at the ipl over lunch.  Must be two different diaphragms for the HD series carbs.  Now why do they provide two different gaskets instead of the diaphragms?  Don't they know I confuse easy.

AND why is diaphragm spelt with a "g"?  Darn greeks and french.

[ENTS]

Joe_

The residue imprint is where a gasket would be sitting on the carb. body.  You can't feel anything there, no raised area, it's just impregnated in the body.  Wish I could remembe how to post a picture here but you can see it in my gallery.  The carb. spent and hr. in the ultrasonic cleaner, it's squeaky clean.

Gonna put the rubbery gasket on and go pressure test it again.  Be back shortly.

Thanks,

[ENTS]

 



Here's the picture of the residue or shadow of what was there.  It looks horrible in that picture yet there is nothing that will come off that carb. body and it's smooth. 

[joe_indi]

That's not a pretty sight.
But, if the saw is a 044, that carb being on it is a bit strange because 044 would not have a carb with limiter caps, which looking at the image this carb has.
That is not a big issue here. getting all that stuff of definitely is.
An attempt with nitro cellulose thinner on a bit of cotton is worth trying.Some nail polish remover should be fine.
If that does not do the job, try a cotton wad soaked with a strong solution of washing soda.
however, it looks like the seating of pump diaphragm would not be 100% even if you remove the stains .
What I do in such cases is fold a strip of 2000 grade water paper over the end of a metal ruler and use it to buff the carb from all directions .This would do the job.
After you do that, take out that strainer, looks as though it could do with a cleaning also.
Joe

[ENTS]

Joe_

Limit caps are off, that's the first thing I did.  Even my 9 yr. old 044 has (had) the caps.

That carb. is soaking in a bath of carb. cleaner.  I'll take a stiff tooth brush to it later.  The screen is brand new.  Just looks bad due to the shadows.

Later,

[ENTS]

Using carb cleaner and Bar Keepers Friend (a friendly powder cleaner) that crud came clean (almost all).  If you blow this macro shot up you'll see some pitting (lower left).  Well, it's going together tomorrow and we'll see how it runs.





Later,

[joe_indi]

I have marked the image where some extra  work might be necessary



joe

[beenthere]

It's an interesting problem to me, and I wonder if you could slide this casting face around on a sheet of 600 grit wet/dry paper laying on a flat piece of glass, and lubricated with a light oil?

Would that give you a smooth, flat, polished surface?    It is something I'd try, not knowing if it would cause a problem. 

[joe_indi]

....... and I wonder if you could slide this casting face around on a sheet of 600 grit wet/dry paper laying on a flat piece of glass, and lubricated with a light oil?

You cannot do that because the choke lever juts below and you wouldn't be able to lay it flat on a piece of glass.That is why I do it with the steel ruler.
joe

[ENTS]

I doubt that I'll be able to get that pitting out.  Just gotta hope it doesn't interfere with the valve action or leak. 

You can slide it around on the glass, you just have to hang the linkage over the edge.  That's basically the way I did it with the powder.  It's a bit clumsy and you can only go back and forth.  The powder is such a fine grit that it didn't leave any lines.  But the 600 grit may leave lines if I can only go back and forth.  May try the steel rule.

Later,

 

[joe_indi]

.......But the 600 grit may leave lines if I can only go back and forth.  May try the steel rule.

Try rubbing the 600g paper on a metal sheet first to reduce the grit.
I did just that today.Worked very well, no pressure leak.
Very fine lines that show as 'buffing marks' will not cause a leak.
Joe

[ENTS]

I picked up 800 grit, figured if you beat up 600 all you're doing is making it 800.  Anyway, worked on that surface for about 10 min.  Didn't want to take anymore material off.  Looks a bit better but that pitting is never gonna come out.



I tell ya what, that 800 grit really cleaned this thing up.  Look at post 14 compared to this one.  Gotta remember this trick for the next one.

Anyway, it get's buttoned up tomorrow.

Next, piston and jug clean up.

[joe_indi]

Now, that looks like another carb altogether!
A really good job.
A pitting near that lower valve seat should not be an issue because its outside the valve seating area.
But, what I would suggest next is a bit unconventional.
Apply a very light coat of grease on the surface before you fit the diaphragm.
This will ensure a leak free condition at the start.
Once the engine starts up the valves' movement will help in getting a more permanent seat.
Joe