MS 440 first muff mod... problems?

[Bieber]

Hey folks!

Did my first muffler mod on my MS 440.

Since I have the German muffler model I first had to drill out some
internal baffles (see photo). I then simply opened up the existing hole to 14mm x 24mm / 0.55" x 0.94". I has now a decent area of
approximately 0.51 sq".
The deflector is made of vanadium alloy steel and screwed into place
with a muffler screen behind it (german version does not have that).

When I fired it up for the first time I noticed how responsive the saw was. wow!

For adjustment I pulled both restrictor caps and opened H and L for another 150 degrees. Put them in again and went to dealer to have i tuned with a tach. I tuned the H to only 13300rpm. The L was at approx. 3000rpm.

Today I did the first few cuts and it ripped through the wood! WAS WORTH THE MOD!


NOW HERE THE MORE IMPORTANT PART:

But I have the notion that something has to be wrong with carb setting since I got the feeling the saw becomes very hot!!!
I hope you can see that in the pictures muffler deflector and screen became colored like gold or yellow... something you see in the beginning when heating up metal.
So does it run too hot aka to lean?
Not sure cause as I said tuned it to only 13300rpm and saw is burbling good when out of wood!
Or is there something else I missed to look for or adjust?

every help/ suggestion is welcome!

thanksopcorn:

 

[Anthony_Va.]

Paranoid? :msp_smile:

You might be though. Did you paint the muffler? If so, maybe your paint is burning. If it's burbling and tuned rich, you should be fine.

 

[Anthony_Va.]

I don't blame ya man. I was paranoid my first time too. You have any pictures of the muffler?

I just don't see how it could overheat if it's set right and everything.

 

[Bieber]

no no I didn't get you wrong

wonder why you asked for paint cause I thought you looked a the pics I just put under the text!?

I did that with the "manage attachements" button and I can see the links to the pics?
Anything I did wrong? Theres another way to post the pics or how do do you do that?

don' beat me ...I'm new here:msp_tongue:

 

[Bieber]

anyone else who can't see the pics?

 

[Anthony_Va.]

Oh ok, I did'nt realize you already had a pic up. I can't really tell the discoloring in the pic though. Does the saw feel really hot?

 

[Bieber]

yes i know the golden shine on the deflector and screen is hard to tell from the pics, but they are there and that makes me think.
I really have the feeling it got hotter in a shorter time after my mod,
but can't say why!?
how important is the L adjusmtent BTW; cause I just tuned that simply by ear but thought it was about 3000rpm with the throttle plate slightly opened

 

[Bieber]

in two days I go logging some big beech trees. there I will see what happens:msp_biggrin:

 

[Evan]

looks good and discoloring is normal special with bare metal.

i never found the need or want to tune with a tack and stay away from dealers as much as possible. tuning by ear in my opion is the best method.

you may also want to tune day to day for difrent air temps and even humidity and elevation. i just keep a screw driver in my pocket and let the saw tell me what it wants.

 

[Anthony_Va.]

Yea, with the mod, youre probably pretty rich at that RPM right now. You may ot be cutting to your full potential. Need to test it in wood and make sure it doesnt burble in the wood.

 

[Evan]

but burbles right as you lift it out of the cut at wot

ive found i like to be slightly richer bucking big wood were the saw is working in the cut for awhile while flooding out chips

 

[Bieber]

thanks evan and anthony for your care about my issue!!!

it burbles goooood out of tha wood. in the wood when under load
it clears nearly up. sometimes it's still slightly there when not under heavy load in the wood. that makes me think as anthony said that it is still on the richer side. and I could go even a bit more to the leaner side. 13300 rpm... so the tach said that as well

 

[Bieber]

burbles while lifting out of the cut... can't remember that detailed but I will listen more closely next time I'm in the wood. maybe i follow your advice evan and gonna tue by ear when get the feeling the saw needs another slight adjustment

 

[Evan]

anytime, yeah sounds slightly rich

 

[Bieber]

not anytime... but you could say as long as I let her cut alone in the wood. If I push her in the burbling goes away.
So in the end to say: slightly rich gonna check it out next time and tell results...

 

[Evan]

lol ill help you anytime. saw sounds fine how it 1/16 of turn might make it run slightly better

 

[Bieber]

Hey guys,

just opened up the muffler a bit more.
Cut down some large beech trees today ( 45" dia in breast height)
and the 440 did more than very well!
Was a difference like day and night after the mod!
Thank you all for making me interested in modding my own saw!!

 

[wyk]

Where is the video?

Besser den augen anstatt, des ohrs zu vertrauen...

Hey guys,

just opened up the muffler a bit more.
Cut down some large beech trees today ( 45" dia in breast height)
and the 440 did more than very well!
Was a difference like day and night after the mod!
Thank you all for making me interested in modding my own saw!!

 

[Anthony_Va.]

thanks evan and anthony for your care about my issue!!!

it burbles goooood out of tha wood. in the wood when under load
it clears nearly up. sometimes it's still slightly there when not under heavy load in the wood. that makes me think as anthony said that it is still on the richer side. and I could go even a bit more to the leaner side. 13300 rpm... so the tach said that as well

Yea, the tach is your friend when learning carbtuning. I ttook me awhile too. Yu can gain a few hundred RPM with a muff mod so setting it at the factory spec (13,500) may be a little rich, but will be safe. If you want it to run to it's full potential, you'll have to get used to tuning it in the cut. My 660 actually runs right at 13,800 with the muff mod, though the spec is 13,000.

 

[RacerX]

Looks good.

Any concern with using nuts and bolts to hold in that screen? I see that you have lock washers under the nuts but I would be concerned with a nut falling off and ending up somewhere that it shouldn't be.