Husqvarna 340/345/350 Jonsered 2141/2145/2150 Information

[modder]

Is that a 346xp after market jug!!! It looks a bit lighter than a new one. I foresee some critiques for grinding on those transfer dividers on the riser but mine still worked great when I did it. I just wish I had put an untouched one on mine after so I could see for sure if it made any difference

 

[old-cat]

Is that a 346xp after market jug!!! It looks a bit lighter than a new one. I foresee some critiques for grinding on those transfer dividers on the riser but mine still worked great when I did it. I just wish I had put an untouched one on mine after so I could see for sure if it made any difference

I ran mine with the pictured cylinder and untouched base, then took it apart and did the base. It sure seemed to make more power the second time!
That's a Meteor cylinder

 

[Mattyo]

So, after looking at your base and mine, yours is a bit more aggressively cut. why not cut that central "fin" (between the transfers) out completely? seems almost silly to have it.

 

[old-cat]

I think it is beneficial to guide the air flow upward, I grind it down to a v shape.

 

[Mattyo]

seems to me like its best to literally have a knife edge at the top of that fin (and the edge towards the connecting rod), and to not grind it down vertically... if guidance upward is the ticket...

then the real trick is to line up the knife edges between the base and the cylinder head

my issue is that I haven't seen many other photos of ported (modded) base adapters other than yours... I would figure that there'd be lots of them...no?

 

[old-cat]

This is only my first attempt, playing around, I don't have access to a dyno I can only play, just like you!
The little 350 has NO respect, few people want to even mess with it. It can be a tad bit troublesome, air leaks, muf screws falling out, etc. etc.

 

[Mattyo]

I ruined a cylinder because my head screws were too long.... torqued the head screws down and fired it up... it fired and ran.... and died. this happened last year. figured it out last night. m5 x 8 x 25mm cylinder head screws need to lose 50 thousanths otherwise they bottom out. DOH!

 

[old-cat]

I ruined a cylinder because my head screws were too long.... torqued the head screws down and fired it up... it fired and ran.... and died. this happened last year. figured it out last night. m5 x 8 x 25mm cylinder head screws need to lose 50 thousanths otherwise they bottom out. DOH!

I took .035" off my base then tried to bolt the cyl on to chk squish. HaHaHa! No go! I had to take off about an eighth inch.

 

[Mattyo]

I took off .020... and still use a gasket.... I didn't check for squish at all because plenty of people do gasket delete w/o checking... so I figured 20 thou was ok ... so far so good

 

[SawTroll]

I took off .020... and still use a gasket.... I didn't check for squish at all because plenty of people do gasket delete w/o checking... so I figured 20 thou was ok ... so far so good

Doing such hings without checking the squish hardly is advisable!

 

[SawTroll]

I ruined a cylinder because my head screws were too long.... torqued the head screws down and fired it up... it fired and ran.... and died. this happened last year. figured it out last night. m5 x 8 x 25mm cylinder head screws need to lose 50 thousanths otherwise they bottom out. DOH!

Spike60 has written about which bolts to use a few times - I believe he recommended the 346xp ones?

 

[Mattyo]

I should have caught the bolt issue... its here in this thread a few places, just didn't see it. One day I'll go through this thread and pull out the pearls and put them in one post

 

[modder]

When I did mine, I removed the divider completely, but a few members advised against is because doing so increased case volume. I also cut the riser down and did some heavy grinding to re-shape the transfers to copy the shape of the 346 and 357 transfers as best I could. (it was a 2150/350 jug) I widened the intake, raised and widened the exhaust, opened the muffler added a hand made base gasket and shaved a little from the top of the piston to get proper squish. I used a 357 intake boot and HDA 199 carb but to be honest, I didn't see much gained from the 357 carb. I sold the saw after getting it dialed in to a friend whom already had a 2150 because he really liked how much power and cutting speed it has over his stock saw. He uses it as his primary saw and the other as backup. The only complaint he has is, its hard on fuel.

 

[SawTroll]

..... The only complaint he has is, its hard on fuel.

That is natural, with the mods you made, with a larger carb, more transfer capasity and more open muffler.

 

[Barnaby]

So I have a stock 350 that has a scored piston (45 lbs pressure), so I purchased a new meteor piston from Bailey's, as well as intake manifold upgrade, gaskets, filters, fuel line and piston bearing. I had to sand some scratching of cylinder exhaust side after removing bonded piston aluminum with acid. Then during reassembly I noticed the new and old pistons are different sizes. "45" is stamped on the cylinder and the new meteor piston is 44mm. I went ahead and reassembled it anyway, not knowing the outcome of whether the ring would seal. The saw is testing at 30 lbs pressure now. Is this 44mm piston the sole cause of this, or is it my cylinder, or both? What would be your suggestion on how to proceed?

 

[Mattyo]

I think this one is pretty obvious. If it says 45 on the top of the cylinder, get a 45mm piston. The thing I've seen recommended is a 353 piston, which doesn't have a dished top. Try that and see what you get for compression.

I think the more pertinant question is one I'm going to use to hijack this... is there are difference between 44mm pistons and 44.3mm pistons? I had the same issue w/ an aftermarket cylinder that I cleaned up, and the saw wouldn't start after I put a new aftermarket 44mm piston in it... so I'm wondering ... do 3 variants exist? 44mm, 44.3 and 45?

 

[modder]

The 44mm piston is for the old 2149, 2147, and the 346 oe. It is way too small to work. You need the 45mm piston for it to work. As long as you didn't take the naskil coating off the cylinder and it is not gouged badly, your cylinder should be fine. After installing the proper piston, you may want to do a vacuum test to be sure the crank seals are still good.

 

[weimedog]

Here is my experiences .. documented on video. They are a lot of fun if you are a mechanical type AND have a reason to cut wood.
https://www.youtube.com/playlist?list=PLtw-MqiEnI4FqI4p_gjbHg3fsoykcdazS

 

[Barnaby]

I think this one is pretty obvious. If it says 45 on the top of the cylinder, get a 45mm piston. The thing I've seen recommended is a 353 piston, which doesn't have a dished top. Try that and see what you get for compression.

I think the more pertinant question is one I'm going to use to hijack this... is there are difference between 44mm pistons and 44.3mm pistons? I had the same issue w/ an aftermarket cylinder that I cleaned up, and the saw wouldn't start after I put a new aftermarket 44mm piston in it... so I'm wondering ... do 3 variants exist? 44mm, 44.3 and 45?

Can I use the 353 piston w/o other modifications? I just want it running again soon, it is as if part of me is dead right now....If I can't cut wood, I feel useless. thanks for the information.

 

[Barnaby]

The 44mm piston is for the old 2149, 2147, and the 346 oe. It is way too small to work. You need the 45mm piston for it to work. As long as you didn't take the naskil coating off the cylinder and it is not gouged badly, your cylinder should be fine. After installing the proper piston, you may want to do a vacuum test to be sure the crank seals are still good.

I used some 220 grit followed by 1000 grit, don't think I took too much off the cylinder. Thanks for giving me some direction. I'll look for a 45 mm piston, any suggestions? How does one do a vacuum test?