MS 440 first muff mod... problems?

[wyk]

Woah, I missed that image. You have nuts INSIDE your muffler? That's..uh.. nuts... Ya got more nuts than I do

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.

 

[oscar4883]

The nuts had me worried a bit as well. At the very least I would take a chisel and score the remaining threads up some. Or tack them if possible. With the bolts going through slightly rounded surfaces over time I would worry about them loosening since they are not sitting totally flat. Otherwise it looks like a real nice job.

 

[Dan_IN_MN]

OP

Check my sig for carb tuning.

 

[ronT2]

The nuts had me worried a bit as well. At the very least I would take a chisel and score the remaining threads up some. Or tack them if possible. With the bolts going through slightly rounded surfaces over time I would worry about them loosening since they are not sitting totally flat. Otherwise it looks like a real nice job.

That or set the heads of the screws on a vice and peen over or stake the ends of the screws so the nut won't fall off.

Sounds like it's running good, glad you're happy with the mod.

 

[CedarRock]

Make sure to check the color of the plug when adjusting the carb. Light brown is best. The darker the richer..the lighter the leaner.

Double-Nut those screws in the muffler and get rid of the washers.

 

[Anthony_Va.]

I did'nt see that pic of the nuts either at first.
I'm not sure if I would leave it like that man. Big trouble if one of those gets into your exhaust port.

If you tack weld or peen the bolts, you won't be able to take them back off to change the screen. Maybe put the nuts on the outside?

 

[ronT2]

I did'nt see that pic of the nuts either at first.
I'm not sure if I would leave it like that man. Big trouble if one of those gets into your exhaust port.

If you tack weld or peen the bolts, you won't be able to take them back off to change the screen. Maybe put the nuts on the outside?

If you just peen them a little you can still get them off... they just won't fall off.

 

[Chris J.]

I'm glad that I'm not the only one who wondered about the nuts inside the muffler. All of the factory deflectors that I've dealt with used metal screws.

 

[Bieber]

Where is the video?

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

Well, I dunno where it is. Should have made a vid seeing it cutting after modding I know. Next time will do it and post it.

...Keine Angst wyk ich halte dich auf dem laufenden!

 

[Bieber]

Thank you for all your advices! honestly:msp_smile:

Will have a look at the inside of muff to check loosening of the nuts. BTW I knew that there was risk of the nuts inside the muff.
The spot welding was a good idea I think. Will do that probably.

BTW what about Loctite? Is there anyting heat resistant enough?

Going to keep you updated to changes

greetings

Sebastian

 

[Miles86]

Really beautiful deflector you made there, pull the spark plug and check the insulator. If it's white or hardly any deposits, then it's running pretty hot, is your plug the correct heat range? I like mine a chocolate brown (plug color):biggrin:

 

[Bieber]

Really beautiful deflector you made there, pull the spark plug and check the insulator. If it's white or hardly any deposits, then it's running pretty hot, is your plug the correct heat range? I like mine a chocolate brown (plug color):biggrin:

thanks man,

checked the color already. was pure brown. so rather a bit too rich...
only problem was didn't even clean the plug up right after the mod so I could be that this brown is still a residue of the time before the mod. Have to clean it up now and check it again.

Have it tuned to 13500 (+ - 100) rpm now and is still burblin (too?) good... so question is if I will go so rpm higher... we`ll see
how she performs the next days...

 

[Bieber]

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.

took that into consideration already since it is burbling very very good at 13500.
I think this is a dumb question and asked times before, but running your 660 with 13800 ... man wouldn't that rise the danger of ring seizure and failure of bearings? just curious cause it maybe the option for me to go higher aswell

 

[wyk]

Honestly, bruder, I would remove the nuts, place the spark screen on the outside of the muffler between the deflector, and use metal tapping screws to hold it in place and tac weld those if they want to come loose. Afterall, we don't want your motorsage to exploden kaputten.

Traurig, wenn ich ein Nazi bin...

 

[Bieber]

Honestly, bruder, I would remove the nuts, place the spark screen on the outside of the muffler between the deflector, and use metal tapping screws to hold it in place and tac weld those if they want to come loose. Afterall, we don't want your motorsage to exploden kaputten.

Traurig, wenn ich ein Nazi bin...

ok, ok, eigentlich hast du schon recht...
Will think about it but problem is I have drilled 1/8" holes for tha screws... so you can imagine what fat metal screws I' ll have to use... what an optical issue!
I'll go to my workbench now and seeking for another solution.
Keep you updated folks... with pics!:tongue2:

wyk, für dich nochmal auf deutsch... werde dich über Änderungen sofort unterrichten!

 

[madhatte]

Afterall, we don't want your motorsage to exploden kaputten

Heh. I love mangling German. It always maken fur good joken.

 

[wyk]

You're worried about how it looks? It could be MUCH worse. The guy whom had my 385XP before me had welded the deflector on permanently with the spark screen! It looked like the muffler had cancer. Here I am cleaning it up mit mein MeisterDremel:

See? Could be worse...

 

[Anthony_Va.]

took that into consideration already since it is burbling very very good at 13500.
I think this is a dumb question and asked times before, but running your 660 with 13800 ... man wouldn't that rise the danger of ring seizure and failure of bearings? just curious cause it maybe the option for me to go higher aswell

Nah man, you'll just be able to feel your mod better. A few hundred rpm will not hurt anything, as long as it's not running lean. Just tune it where it cleans up good in the cut and see where it's at. Chances are you'll gain a few hundred RPM. That few hundred is where you will feel the power. There are guys running 660 ported worksaws everyday at 14K or more. So yea, short answer: Tune it to where it's running optimum, and don't worry about anything.