update on 041 fb rebuild

[Deer Assassin]

i dropped a 18inch white oak on it a while back busted a quarter size hole in the crankcase along with bar and chain destroyed.

i found a used crankcase on ebay for 10 bucks it had the crank n rod with it

when it arrived it turned good n smooth so i tore mine down ( having no idea what im doing) swapped piston and cylinder points clutch ect

then i broke the piston ring putting the cyl on the new ring came today i took my time got it all back together


well.............. it runs

but a few issues

1. the dang muffler wont stay on i put thread lock on it but it seems to be stripped in the cyl (i had issues with this before tree dropping on it.
what do you guys recommend should i tap the cyl


2. i was hoping not to have to mess with the carb as it was fine on other saw and nothing changed same cyl n piston but with the new ring it seems to have more compression ( i havent checked before and after) but when it runs it seems to idle high and the idle screw isnt touching any thing only thing i can adjust is to adjust it higher
when u run it up it runs good except WOT it seems to bog down if you ease off throttle it runs back up

i figure i might need to adjust carb or would the timing being off cause it

i kinda screwed up when i swapped the points over by removing the whole assy
i eyeballed it and put it the same way on the other i never checked the timing



just looking for a lil advise

thanks

 

[o8f150]

idle and the wot sounds like it is running lean,fatten it up

 

[JoshF]

Just try backing the low screw out until the chain stops turning then see what it does

 

[hotshot]

Hand tap to 6mm

Hand tap the holes from 5 to 6mm, then drill out the flange. Take your time to keep the tap straight as the material is real soft.

 

[SpaayDawg]

The muffler is the one place besides the cylinder bolts that I use red loctite. I usually get the recoil/gas tank bolted in after the cylinder. Then bolt the muffler to the cylinder loosely. get the handle housing bolts started through the gas tank, cylinder, then tighten them down. Use the handle housing and muffler cover to get the muffler lined up where it needs to be before tightening the muffler flange to cylinder bolts down good. It is a process, as manufacturing wasn't as good back then as it is now, but taking a little bit of time to just start all the bolts gets everything lined up so you can really torque on 'em.

Bogging at WOT seems to me you have your H jet screw backed out too far, and racing at idle you have the L screw too lean. A good starting point for me with these saws is 3/4 - 7/8 of a turn out on both, then set the LA screw so after touching the butterfly plate screw another 1-1/2 turns. There are so many gaskets in there be sure you don't have an air leak that could cause a piston failure.

You're almost there!

 

[Deer Assassin]

the carb and intake gaskets were in bad shape


i just ordered a gasket kit for the saw

i got to pull all the carb intake stuff off to get to jug to tap for the muffler

so im going to replace that old gaskets i was afraid i might have an air leak to

 

[Deer Assassin]

Hand tap the holes from 5 to 6mm, then drill out the flange. Take your time to keep the tap straight as the material is real soft.

i can handle the hand tapping

what do you mean drill out flange after i tap ?

 

[SpaayDawg]

After tapping the cyliner, drill out the flange of the muffler to accept the larger bolt you will be using.

 

[Deer Assassin]

duh it makes sense now as i have already done it


tapped to m6x1.0

going to morrow to pick up some socket head cap screws

 

[bobt]

Hey there Deer Assasin,

Good for you on rebuilding an 041. Those saws have lots of torgue, and are still a force to be reconed with even now.

I can't say from what you wrote so far if you have reassembled the stator plate to the new crankcase in a position that will provide the correct spark timing to make the saw run right. I suspect that you may run into problems.

The spark timing is critical on engines and the 041 is no exception. The timing is correct when the spark comes exactly at 2.5 mm before top dead center. If the spark is too late, the saw will probably run, but without the power that it should have. (it will be a dog) If the timing is too advanced, (early) the saw will probably kick back violently and almost rip the starter handle from your fingers.

Without the correct tools, such as a dial indicator and a way to determine exactly when the points open, you will have to figure the timing out by trial and error.

Be prepared to remove the starter and gas tank assembly and flywheel, and rotate the stator plate by small increments until the saw is snappy when the throttle is applied. It should accept the throttle quickly and rev up to full throttle in an instant.

Bob

 

[Deer Assassin]

Hey there Deer Assasin,

Good for you on rebuilding an 041. Those saws have lots of torgue, and are still a force to be reconed with even now.

I can't say from what you wrote so far if you have reassembled the stator plate to the new crankcase in a position that will provide the correct spark timing to make the saw run right. I suspect that you may run into problems.

The spark timing is critical on engines and the 041 is no exception. The timing is correct when the spark comes exactly at 2.5 mm before top dead center. If the spark is too late, the saw will probably run, but without the power that it should have. (it will be a dog) If the timing is too advanced, (early) the saw will probably kick back violently and almost rip the starter handle from your fingers.

Without the correct tools, such as a dial indicator and a way to determine exactly when the points open, you will have to figure the timing out by trial and error.

Be prepared to remove the starter and gas tank assembly and flywheel, and rotate the stator plate by small increments until the saw is snappy when the throttle is applied. It should accept the throttle quickly and rev up to full throttle in an instant.

Bob

bob i was afraid of that but i think i have it close

it accepts throttle quick and has power

and i have no snap back on starter rope

i will know more next week gasket set on the way for intake n carb
then i will try to tune it

 

[Deer Assassin]

what fuel ratio do yall think i should run in this ole thing

40:1
or 50:1

 

[bobt]

what fuel ratio do yall think i should run in this ole thing

40:1
or 50:1

Either will be fine.

I use Stihl Ultra these days, but my 041 had a diet of the orange bottle Stihl oil for many years. I mix a bottle of Ultra that is the size for 50:1 in 2 and a half gallons of gas, but my can only holds a little over 2 gals, so it is mixed probably closer to 40:1.

Glad to hear that your ignition timing seems to be close to optimal.

Bob