1st Successful MOD !

[dastevoe]

Well success at last !
Thanks to Cut4fun, Al Smith and Woodworkingboy for there guidence in my first Woods Modded 038 super !
I fired up the BEAST this morning and I have to say I'm HOOKED.
Put it together,took it out, pulled & pulled....nothing ?
Pulled off the air filter,dribbled in a bit of gas.....pulled.....POP... POP...POP...away she went !!
I set the carb 1 3/8 open H&L and it seemed ok. I didn't run it a long time,maybe 10 minutes didn't get it in the wood yet (still need to find a muffler cover for it,it was missing when I got the saw).
Here are my #'s : machined .004 from bottom of cyl.
got squish to .021" with no gasket.
Widened exhaust by 1.75mm/side to total width of 30mm staying ~2mm from each side of piston window.This was as close as I dared go to the sides giving me 60% of the bore dia.
Bevelled out NICE AND WIDE to the muffler then high polish.
Intake was widened to within 2mm of window as well,again NICE WIDE BEVELout to the boot.Polish up to 400 grit.
No compression #'s (borrowed guage not working!),but I'll try to get some.
New fuel p/u line and impulse line.
This came to me as a "saw in a box" so I have no base line to compare to.
Now I'm staring at a magnum P&C on my bench with bad intentions
Any pointers on getting this puppy broken in chime in please.
Thanks again,
Steve

 

[gf beranek]

Cool. Glad to hear your success.

 

[darkstar]

Sounds great , something i want to do badly.
Awesome.

 

[Al Smith]

To break one in set it slightly rich and run maybe 8-10 tanks of fuel through it .Then set it where it's supposed to be and run it like you stole it .

When you get a new piston and cylinder from Stihl it's pretty well honed to good tolerances .If however you rering a piston you have to remember the rings have to comform to the cylinders ovality etc because there will be some . It takes more time than most think .Fact is it took me the best part of last summer to break in the Rocky special .

When those rings get seated there will be no doubt in your mind because you aren't pulling over a stocker any more . My 38 Mag pulls over at least as hard as a stock 066 .

One problem with these folks say modifying an 084 is the fact they have a hard time getting enough run time on that large of a saw to seat the rings . I have a 125 Mac that has the same problem ,Done 4-5 years ago and still not broken in .

 

[Al Smith]

I forgot to mention something that is paramont .Run maybe part of a tank then check your bolts for torque .Run two -three more and do it again . Let the saw cool before you put the tights to it .

 

[woodworkingboy]

If you put in new rings, I'd run petroleum based two cycle oil until it's broken in, then switch to a good synthetic. Look for sights and sounds of overheating.

 

[Swe#kipp]

As Al said, a bit rich, wide open throttle in the wood but out of the wood be gentle
It's fun aint it, you get a very different animal in your hands after some porting and polishing

 

[GASoline71]

If you put in new rings, I'd run petroleum based two cycle oil until it's broken in, then switch to a good synthetic. Look for sights and sounds of overheating.

Jay... unlike automotive motor oils... you can run the good synthetic 2 stroke oil from the first moment you start a new saw... no problems...

Stihl even says it's okay to use their full synthetic Ultra during "break in"...

Gary

 

[Al Smith]

Without sounding somewhat sexist break the saw in somewhat gently then ride that bitch for all she's worth .You want to run them hard ,ride them hard .

 

[woodworkingboy]

Jay... unlike automotive motor oils... you can run the good synthetic 2 stroke oil from the first moment you start a new saw... no problems...

Stihl even says it's okay to use their full synthetic Ultra during "break in"...

Gary

Right Gar, I know that is one general consensus. I did some experimenting around, after reading a lot of conflicting opinions on which type oil to use on a modded saw that was going through break in. With the synthetic on a Husky single ring, I was getting a lot of resin coming out the exhaust, a sticky mess really, presumably the oil blowing by the ring that hadn't seated properly yet. The exhaust port was covered with it. 32/1 mix, by the way. That wasn't the case with the dino oil to that extent, when I switched. After break in, basically nothing coming out the exhaust with synthetic.

Just wondering if maybe the higher compression in a modded saw is a factor? I'm not that conclusive about it, but I've gone to doing that practice with the dino oil until break in. I know that the synthetics have come a long way. Running Castrol or Mobil synthetic these days.

 

[Al Smith]

Kind of funny ,on say the auto engines of 10 years ago,they were all shipped with "break in " oil .Really just oil with STP in it . The newer ones are so danged tight you have to run 5W 20 in then or they can't pump it .The new tolerances are in microns rather than thou s' .Tight like a mouses ear ,among other things .

I can't comment on synthetic oils,never used them myself .My buddy Louie the one time kart racer swore by the stuff though .

 

[dastevoe]

Got a compression guage on it this am.,150psi.
Seems a little low ?? for a jug with .021 squish? Maybe not !I'm new at this game.
1 tank af fuel on new piston & rings ,could go higher with seat in of rings maybe ?? No matter...it starts and runs fine,I'm not racing this thing anyway. Wish I had a stocker sitting arround to compare to after a while.
Next piece of the equasion is learning more about chains
Steve

 

[Al Smith]

I wouldn't be too concerned on the comp readings .It will come up .Besides that too many people worry about comp readings and tachometers any way .

When you are pulling that thing over to get comp readings that is called static readings or basically at rest .When it runs ,that is called dynamic ,or under operating conditions .

Because of the fact of the way a two cycle engine in effect seals the rings under power that reading would be higher and get higher as the rings seat .

Lay that thing to the wood and forget about a race chain .You can get that later ,work on the saw .

 

[woodworkingboy]

What Al says. Especially if new rings, look for compression increase. Some gauges read low too

 

[squisher]

Yah that's what I love about the quality tools nowadays. You need a compression gauge to check the compression gauge.

 

[Al Smith]

That comp can be misleading .The 125 Mac I made the iron liner for can be started without the decomp .Which is a feat all in it's own because that is 123 CC at 7.5 to 1 to comp .The rings aren't seated yet ,simple as that .

That thing however has gnawed into 54 " of silver maple with a 48" hardnose buried so it's got the power--under power . If that thing had blow by on the rings no way could it handle that much bar that well .

Like I said ,it just takes time on the ring thing .

 

[woodworkingboy]

Yah that's what I love about the quality tools nowadays. You need a compression gauge to check the compression gauge.

Well, you have to at least start off with the right kind, some have the check valve at the top of the hose, you want it at the bottom at the cylinder connection.

 

[dastevoe]

[/QUOTE]Lay that thing to the wood and forget about a race chain .You can get that later ,work on the saw .[/QUOTE]

Well I layed her to the wood, 4 or 5 , 12"+ frozen maple firewood logs.
It's got some "BITE" to back-up that sweet "BARK".
The carb needed a little tweeking as I went .It's dialed in at 1 3/8 H,1 1/4 L.Maybe a tad rich on the H for now, I'll run a few more tanks through it then reasess it.Seems to have lots of revs too,but I'm ridin' her gently ...FOR NOW
The missus came down into the shop and caught me playing with one of the other saws and said "you should be on an episode of PIMP MY SAW" I guess you had to be there :what:
Anyhow... this saw stuff is fun!
Steve