ready...set..MOD!!

[powerking]

Ok I am ready to mod a bit...which would be easier to mod..my stihl 023 or the Husky 254? Just looking to start playing around with either one...I know there not a 066, but that will come soon enough!!
Thanks
Rich

 

[SawGarage]

Rich,

you will get more gains from the saw with more displacement...

you tell me what you want to start with

J

 

[powerking]

J I have already did the plastic intake tube mod, and I also "opened" up the muffler just a bit. It does really seem scream more. This saw (the hsuky 254) has a brand new husky piston in it. I was running it last year and it locked right up on me...Piston was in bad shape, but the cylinder I had sent over to my uncles saw shop, and they were able to clean it up no prob. I only have the HS screw out 1 turn, so, as not to run it to lean.....Whats next for mods that you know of? I'm ready for more!!!
Rich

 

[SawGarage]

RICH! you may want to adjust the screw out a bit more with some mods...should be ATLEAST 1 turn out.

remember, it's like a hose bib/faucet...you screw it IN to CLOSE IT/LEAN IT OUT OUT to RICHEN

search '4 stroking' in the search function...should get you in the ball park... you don't want to replace ANOTHER piston!!!

you should want it to sound like it is loading up JUST a bit out of the wood (warmed up...cold it will always do this.)

I'd pop the muffler off, and measure the exhaust port exit. make your muffler outlet about 80-85% of that size to start. remove any internal restriction.

next area to work on, would be port work to the cyl...



J

 

[powerking]

..just found this post of mine here again....SawGarage....What would benefit more? The intake or exhaust porting?

 

[SawGarage]

if you have the cyl off, it would make sense to do both. widen to 1mm (each side) of the witness lines of the piston that show on the cyl to start... don't raise/lower the ports at all (at 1st...) more on that later...

 

[powerking]

Hmmm..witness lines??? Help me out with that one please!
Rich:msp_mellow:

 

[SawGarage]

Hmmm..witness lines??? Help me out with that one please!
Rich:msp_mellow:

be VERY careful... i only have ONE 254 cyl if you smoke yours! oke:

look in the cyl, you'll see where the piston skirt rides up the cyl wall... follow those lines up to the ports, and cut NO MORE than within 1mm on each side of the port...

Jay

 

[powerking]

Ok, I did widen the exhaust port up to 75 -80% of the 45 mm piston size I had, forgot to take a pic though! I have attatched a pic of the "front exit" muffler mod that I did. the saw really seemed to respond well to those 2 mods today and really revs up well. My tach says it was hitting almost 14,200 before I had to richen it up and get it to 4 stroke....I think I'm about almost 2 full turns out on the HS screw. I just have to find some spark arrestor screen for that muff, now that theres a big hole front and center! Any input is appreciated! good or bad!!
Regards
RichView attachment 190591

 

[SawGarage]

Ok, I did widen the exhaust port up to 75 -80% of the 45 mm piston size I had, forgot to take a pic though! I have attatched a pic of the "front exit" muffler mod that I did. the saw really seemed to respond well to those 2 mods today and really revs up well. My tach says it was hitting almost 14,200 before I had to richen it up and get it to 4 stroke....I think I'm about almost 2 full turns out on the HS screw. I just have to find some spark arrestor screen for that muff, now that theres a big hole front and center! Any input is appreciated! good or bad!!
Regards
RichView attachment 190591

A general rule of thumb is 65-70% of the total bore dia transferred to the cyl wall... did you maintain enough cyl wall for the piston to ride on?! this is why I suggested staying within 1mm of with witness lines on each side of the skirt (so, port is 2mm smaller than the intake skirt, and exhaust side is about 2mm smaller than the exhaust side skirt... ) it doesn't take MUCH to go too far...


cool muffler mod.. you tryin to burn the bark on fire?!? lol

there's a thread (do a google search as the AS search function SUX!! :bang on a spark screen that might fit that pipe... depending on the size...

if you want a bit more out of the saw, and we can cut the cyl SLOWLY, we can work (SLOWLY!!!) on port timing increases

J

 

[powerking]

sorry bout that J, I meant to say 65 -70%...I saw a post from ncfarmboy and I used the calculation of 45mm=29.25-31.5mm and I think I'm right around 29mm. If I did that on the intake port, i would be into the screw bosses, so thats why I didnt touch that side. That port in the front of the muff is outof a shim I had. the I.D is .5in I wonder if thats going to be too much? I could always machine something down smaller if need be.
Rich

 

[ncfarmboy]

sorry bout that J, I meant to say 65 -70%...I saw a post from ncfarmboy and I used the calculation of 45mm=29.25-31.5mm and I think I'm right around 29mm. If I did that on the intake port, i would be into the screw bosses, so thats why I didnt touch that side. That port in the front of the muff is outof a shim I had. the I.D is .5in I wonder if thats going to be too much? I could always machine something down smaller if need be.
Rich

Widen the inside of the cyl. to 29.25-31.5mm or to .5-1mm from witness lines. Attached pic is an example. Intake port just grind out, square up leaving enough meat to safely hold carb screws.
Shep

 

[powerking]

...So the witness lines would be the max width I could grind out to? In my case 45mm @ 65-70% = 31.5mm max.....
Rich

 

[SawGarage]

...So the witness lines would be the max width I could grind out to? In my case 45mm @ 65-70% = 31.5mm max.....
Rich

Rich, it comes down to WHICH of those two you hit 1st (most likely the witness lines...) if you get to within 1mm on each side of the skirt (2mm total for intake side, and 2mm for exhaust side) of your witness lines, but have NOT hit 70%, you need to stay there. IF you measure out 70% of the bore, it it's BEFORE the witness lines, you'll want to STOP @ that point...

clear as mud??

J

 

[powerking]

Got a chance to REALLY work my freshly ported out 254 today with all the downed tree's and let me tell you that thing sings! I was so proud of that saw today!! I was kicking an ms290 all over the place! It's quite loud with the front ported muffler, but I am proud of it!
Rich

 

[SawGarage]

GOOD to hear! fantastic stuff!!

yeah, It SHOULD kick a ms290 from here to there!! now THAT'S a given (probably would beat it in STOCK form... BUT, be a HELL of a lot lighter too!!

J