346xp old style exhuast mod

[Charlieh]

ok a little picture thread, I bought this: (sorry about photo quality my camera is on the way out)

 

anyway it was bought as a non runner, after a bit of messing about i decided the carb was the source of the problem,

 

poor photo but you can just make out the lump of blue pastic that was sitting under the metering needle spring, causing it to constantly flood the engine,

 

 

Once that was solved it ran quite nicely, then I did a muffler mod on it, opening up the exhuast outlet area to about 75% of the exhuast port (i wanted to be a bit conservative as its my first attempt and a smaller saw, so i didnt see the need to go to 85%+)

 

 

 

After removing the exhuast I had to drill two holes and then filed and dremmel out the edges on both the exhuast and the mounting plate, the problem with the 346 exhuast is that it doesnt mount tight up to the mounting bracket so once you have drilled and filed the exhuast you then have to use needle nosed pliers to gently bend the outside of the hole you have created outwards so it touchs the mounting plate,

 

I also drilled a hole in the internal baffle as well, as i didnt go to the hastle of spliting the muffler apart, i drilled this hole off center to the exhuast port and new opening so it doesnt have a direct line through, my reasoning for this is that if you push the saw into something bushy like a conifer when limbing and a branch does push the screen in at least its not going to push it straight on/into the the piston

 

 

I have then just used a small peice of isopon car body repair mesh as a spark arrestor mounted between the exhuast body and mounting plate, just to stop debris entering the exhuast

 

all told took just over an hour with the retune, which i did by ear need to get it on the tacho really now,

 

My first impressions are good, the saw pics up revs very fast, it seamingly cuts faster, the noise isnt as bad as i was expecting its certainly quiter than my 254xp (and less vibes and less thirsty). The fuel economy doesnt seem to have been adversly effected and im very happy, I used an older saw for this effort as its not a very tidy job but now i understand how to go about things i would be happier doing it on some of my newer saws, oh and i cleaned the huge amount of build up out of the exhust port which was probably about 1.5mm deep all the way around the port

 

so far the saw has cut about 2 trailer loads (7ftx4ftx2ft) of logs mounted to my portek log master, on one tank of fuel its great it will go into to timber the full legth of the bar (15") and doesnt drop the revs noticably at all,

 

my advice.....do it!

[18 stoner]

Nice one charlieh, you got the bug now then:001_cool:

 

As a thought, if you do another, perhaps split the can open and remove the baffle completely, make the port on opposite side to the standard one then you wouldnt need the spark screen.

 

What you have done seems like a real good mod for a smaller saw, quick and cheap! Nice one!

[High Scale]

Nice job, I have split the can on my spare 361 exhaust and pulled the baffle out, splitting the can though, is a pain, I then blew some holes in it trying to weld the holes that the removal of the baffles left.

 

I have now left the exhaust with a friend who can actually weld.