044 hybrid lacks balls in the cut

[langdon19]

Hi all
I bought a 44 with a toasted top end. Mate sold me a second hand 46 genuine slug and jug. Assembled saw and has less power than my 44.
When you are in the cut the saw looses revs and you have to lift the saw up a bit to get the revs up then drop it back in, repeat repeat, it should power through this I would think. Running a 25” bar.
Saw holds pressure and vac.
Swapped the carbs between my 44 and 44 hybrid and no better.
Both saws give 150 psi on an automotive tester.
I’m stumped
Going to pull the exhaust again and have a look.

 

[cscltd]

Is it an oem Stihl cylinder or $25 ebay special one.
i got a ts800 cutoff in with new $25 cylinder and it Boggs and spits back so bad the strato port is full of fuel and won’t cut at all and it’s 99cc engine

 

[langdon19]

Yes mate oem 046, yeah it’s not new but had enough life left to do the build

 

[SteveSr]

Yes mate oem 046, yeah it’s not new but had enough life left to do the build

How do you know OEM? Post some photos of the casting markings on the lower sides of the jug.

 

[Evan]

Did you instal base gasket?

Id remove it bumping compression may wake ut up. If you do check squish atleast make sure it turns over by hand first.

My 44/046 makes tons of tourqe my squish is bought .002 its mildly ported. Im running meteor piston cabar rings. Dont know the compression. Feels like alot.

Are your high low needles about 1 turn out?

 

[singinwoodwackr]

Did you open up the exhaust too much via muffler mod?

 

[langdon19]

I will try to get some photos of the jug later or tomorrow.
Yes I am running a base gasket, h jet is a turn out, low is 1 3/4 out as it would not Rev up at 1 1/4, with the 44 Carb installed it still lacks balls.
I have not opened the muffler up. I am going to pull the muffler abs check spark arrester

 

[Maintenance supervisor]

Is it the walbro carburetor?
Do you know how to check your squish band height?
You could have an enormous amount making combustion very inefficient.

 

[langdon19]

Yes it is the walbro carb.
No I have never touched squish band height or measured it.

 

[Maintenance supervisor]

Honestly checking the squish is relatively easy. Hardware store and get some
030 solder soft, bend it into a leg and insert it into the spark plug hole. Rotate the engine by hand ( take starter off and rotate with flywheel) , feel when it contacts the edge of the cylinder!
Then take calipers and measure the solder crush.
If it doesn't make contact folder and twist the end of the solder,and don't hamfist it, it'll take aliitlte effort but not shoulder popping strength.
The walbro is usually a good carb.

 

[langdon19]

I have some solder, have a flat out day ahead of me at this stage. Will get onto it when time permits.
Thanks all

 

[teacherman]

Hi all
I bought a 44 with a toasted top end. Mate sold me a second hand 46 genuine slug and jug. Assembled saw and has less power than my 44.
When you are in the cut the saw looses revs and you have to lift the saw up a bit to get the revs up then drop it back in, repeat repeat, it should power through this I would think. Running a 25” bar.
Saw holds pressure and vac.
Swapped the carbs between my 44 and 44 hybrid and no better.
Both saws give 150 psi on an automotive tester.
I’m stumped
Going to pull the exhaust again and have a look.

Might want to have a look into the cause for the previous piston's toasting. Normally the 046/460 is a really strong performer, with the same 36 mm stroke as the 044, so it seems it should work fine. But if there is a bad seal causing an air leak, well, I'd rule that out for certain before risking a nice oem 52 mm top end. Maybe you already did that, if so please ignore my ramblings.

 

[langdon19]

Might want to have a look into the cause for the previous piston's toasting. Normally the 046/460 is a really strong performer, with the same 36 mm stroke as the 044, so it seems it should work fine. But if there is a bad seal causing an air leak, well, I'd rule that out for certain before risking a nice oem 52 mm top end. Maybe you already did that, if so please ignore my ramblings.

Hole in impulse line, clutch side crank seal leaking.
All rectified, new seals impulse line and passes pressure vac test

 

[muddy42]

Sorry if this is obvious but something in the clutch could be slipping? Weak springs?

 

[langdon19]

Sorry if this is obvious but something in the clutch could be slipping? Weak springs?

Don’t think so mate the revs of the motor drop in the cut and won’t pick back up unless you lift it out of the cut.

 

[langdon19]

Only marking I can see without pulling the jug

 

[langdon19]

Squish is about .035 with base gasket

 

[langdon19]

Spark arrestor is clean
One thing that was weird to me was that when I originally set the walbro to 1 1/4 turns out on the L and 1 out on the H the saw would idle but not rev up
I ended up turning the L jet out a bit more until it rev’d up happily
When I put the 44 zama carb on I just swapped it straight on as the 44 is an animal. The hybrid was still boggy.

 

[angelo c]

Make sure you're using "electrical solder" and not welding solder. You wanna start with solder diameter no greater than .020 and "twist" it if needed. If the solder is over .040 it just ain't gonna "squish" down enough to be accurate.
Also have you tried the same bar and chain on another saw ?
Some times an overly aggressive raker height will bog ANY saw. I've had plenty of saws come in that "won't run- weak on power" only to find the sharpener was a bit to anxious.

 

[muddy42]

1 3/4 turns is a bit much. Is the tuning consistent at that or does it lose it over time, does the saw run held upside down, sideways etc.?

Can you describe how you perform the vac and pressure test? What I mean is do you have the saw as fully assembled as possible - piece of rubber behind the carb, impulse line connected but blocked with a golf tee? I have been tricked by doing a partial test of a 460, this way you are testing everything - intake boot, impulse line etc. Plug the decomp to take that out of the equation.

Try a shorter bar and chain and see if that helps? Try a new chain. 25' is quite long for this saw.

There could be something sticking in the carb, have you cleaned it totally?

Try removing the fuel filter (temporarily). This can highlight fuel flow problems. check fuel tank breather. what happens if you cut with the saw held sideways and the fuel cap off?