help opening an olympyk 962

[tony marks]

okay. the exhaust leaves the piston via exits to the left and right of the exhaust port. it then goes all the way to the front of the muffler ,where its reflected into an 1/2 inch pipe .. this pipe runs back thru the muffler and out the chain side,, on top left of mufler. what i dont know is ,will i mess up some kind of porting formula if i open it so the exhaust
goes out the front instead of having to go back thru that half inch exhaust,,and out the side. its not been moded so this is factory setup. thanks if anybody can help. tm

 

[Mack]

Tony,
Is this the older Olympyk style with the single round port on the chain side? Or the Emak/Efco style?
I'm convinced you get a bit more out of the older style, at least the older saws seemed to spool up a bit faster. Nothing scientific here, just a gut feeling. Next time I get an older one in the shop I'll try to run it against a new one.

 

[oakman]

hi tony, it sounds like maybe you are confusing the transfer ports with the exhaust port. when you look through the exhaust port, and see more ports about 90 degrees or so on either side of it, those are the transfer ports. or do you mean there's 2 holes in the exhaust port itself? anyhow, i don't know how old the saw is, but i'd say a 1/2 inch i.d. pipe is too small. probly tuned down to epa specs. i'd open her up, but i wouldn't place the pipes directly in front of the exhaust ports. it will be way loud. if you can, put them off on either side. my theory on that is the exhaust is coming out at fairly high velocity so at least it has to bounce off the front of the muffler, and then over to the outlets. here's my 066. i completely gutted out the can, matched up the muffler to the exhaust port, and added the 2 side outlets. the original hole was about 3/8 diameter. the thing sounded like a japanese gas powered sewing machine or something. really high pitched and tinny. very annoying, even with muffs on. now it sounds like a good strong running dirt bike. and does it run! i luv when i crank it up on a cold morning, and the 2 pipes blast out some smoke. it looks like a dragon waking up, ready to chomp down. but what the hell, it is! go for it and open it up. you won't hurt it. you'll most likely have to fatten it up a bit. if ya get stuck, send it up to me. i'll weld some pipes on for nuthin. good luck pal.

 

[tony marks]

yep ,this is the old style i guess... it only has one exhaust pipe ... exhaust leaves the cylinder into the muffler ,,is split to rite and left ,,the tothr front of the muffler wherethe opening for this pipe is...
then back thru the pipe,, to where it exits thru the pipe out the left top of the muffler.. heres where it gets bad...
last nite i sez to my self ,,i sez self,, go fer it... so i drilled three holes 1/2 inch in the front ,,at the point where normally it
start backthru the pipe . .
now it all goes out the front.
i then,, adjust the high in just a tad and its cuttin like hell.
now my only worry is if i might have it too lean . it seems to me, if i was gettin what i wanted done ,,i should have had to richen the h and l.
none of the changes are hard to undo with a little plate accross the front.
thanks oakman ,for the offer. but really i got dans 372 if i want to get really quick in cut. im just playin . now its cuttin on par with my 036. if it can stand it. sorry for the long post and thanks.

 

[tony marks]

if yall hear an mild explosion down this way ,,u will know ,tony been busy,,,adjustin saws.

 

[jokers]

Hi Oakman
Nice work on your 066, looks good.

I think Tony was speaking of the convoluted and torturous path the exhaust follows in the mufflers of Emak/Efco saws. You wanna see restricted, take a look inside one sometime.

Russ

 

[tony marks]

ithink tortured is the rite wd. it does do some cuttin flips,, in there before it is finally expelled out the exhaust pipe. but mine dont do that any more and its no louder. it is a quicker saw tho.
still i wish the alteration had called for richer mixture instead of a little leaner to get what i wanted as to cutting . we ll see.

 

[Tony Snyder]

It may be viewed that the exhaust path on an Efco is not a direct as on some other brands, but fact is, a 962 still runs pretty darn good just as is.

But, at the same time I suspect this would offer good opportunity for the modified saw builder. I have been tempted to have a 981 built for 5 cubic inch show at low level local competitions. I would think its main competitor would be the older 81cc Huskys.

 

[tony marks]

u are rite tony it did run good ,,just wouldnt match my 036,,same cc.
havnt had the chance to compare since i opened it up .. but i can tell u it now cuts faster,than it did.. it does seem to be a good candidate,, for a true mod job...
ps by the way ive had it in real heavy cutt and it likes it ,,so apparently i didnt get it to lean.