1998 Husqvarna 340 conversion to 346XP

[Freddie Helm]

Hey guys, first time poster here. My father in law bought himself a new Stihl and this one was collecting dust so I figured I'd take it over and make something out of it. Didn't take 10 minutes of googling before I joined this site. The parts I have researched so far that I need to perform this conversion are as follows:
(ALL OEM)
350 Cylinder base- 503 88 59-01
Bolts for Base- 50321 78-27
346XP Top End Kit- 544 14 29-08 (This edition has the decompression valve, the *******-07 does not, could someone explain a little about this to me? I'm not sure what it's for and what the benefits are of it)
346XP Cylinder Bolts- 503 21 74-25

Aside from the gaskets, this is all I have read is absolutely necessary for the conversion. That being said, once the conversion is made what about the carburetor/muffler (&muffler mod)? The thread that Stumpy made about his conversion from a 345 to a 346xp mentioned the use of the 357 carburetor and the installion of a 346xp muffler if I am correct I just want the saw to run as strong as it can but I don't mind spending the extra money to make it right all the way through.

Any input is welcome! I'm an amateur but I can find my way around engines decently I think.

 

[SawTroll]

The OEM NE346xp kits all are bored for the decomp valve, the different part numbers are about if the hole has the decomp valve in it, or a bolt to plug the hole (which actually is the better option imo, unless you really need the decomp).

You will have to grind away some plastic inside the case, as well as having the right parts - but I guess you know that after your research?

Calling this a "conversion to 346xp" is of course not correct, as there are lots of quality and "feature" related differences between the models, that aren't addressed by adapting a 346xp top end to a 340. The resultant saw may perform like a 346xp if done right, but it never will be one.

 

[Freddie Helm]

Understood. Yes I did note that the plastic would need to be grinded. Luckily I got a nice Dremel set for Christmas, lol. I just wanted to see if there has been any new discoveries with the "conversion".

 

[blsnelling]

 

[redunshee]

Is the 357 intake and carb a direct bolt on or are some modifications needed. Might try it on my 350 with a 346 p&c.

 

[old guy]

When I put the zama el42 on a 346 I had to grind a little more room for the choke- on off stuff to fit out the rear of the box.
You also have to use the 357 air filter& and it's elbow.

 

[blsnelling]

Is the 357 intake and carb a direct bolt on or are some modifications needed. Might try it on my 350 with a 346 p&c.

It's tight, but everything will fit right up….with one exception. You do have to grind off one part of the intake block.

 

[blsnelling]

When I put the zama el42 on a 346 I had to grind a little more room for the choke- on off stuff to fit out the rear of the box.
You also have to use the 357 air filter& and it's elbow.

It's tight, but it does fit without modification.

 

[Freddie Helm]

Ok sounds like nobody has any objection to the parts I listed above. Thanks for all of your help!