Husqvarna 351 conversion to 346xp

[born to hunt]

Hi all-
I’m sure this has been posted about ad nauseum but…I inherited a 351 and it needs a new carb. Problem is I own a 346xp and a 550 xp already and was wondering how much of a job it will be to do a 346 conversion? or is it better to just get a new carb and call it good.

If the latter…carb recommendations?

Thanks

Bob

 

[Bob Hedgecutter]

They are a nice saw as is really, mag cased predecessor of the 353.
New top end, new decal on the starter and you have a 346.
But you already have a 346, so if the 351 top end is okay......

Some people like to put the carb from a 359 on 346's......

 

[born to hunt]

How much time and effort is involved in the new top end?
How much $$ ?

I’ve rebuilt carbs before, am a fix-it dad to 10 kids..some with cars…but never done a chainsaw motor takedown before.

 

[born to hunt]

How much time and effort is involved in the new top end?
How much $$ ?

I’ve rebuilt carbs before, am a fix-it dad to 10 kids..some with cars…but never done a chainsaw motor take

 

[Bob Hedgecutter]

How much time and effort is involved in the new top end?
How much $$ ?

I’ve rebuilt carbs before, am a fix-it dad to 10 kids..some with cars…but never done a chainsaw motor takedown before.

As it is your first one- maybe 3 hours tops?
But unless you can find good OEM 346 top ends and unless the 351 top end is roached- why bother?
Basically you pull the intake tract and muffler off the cylinder- undo the 4 bolts holding the cylinder down, remove cylinder- remove piston- fit new piston, new cylinder and reverse the rest of the removal stages until you have a complete saw again with no left over major parts.
Get the carb sorted and run the saw- compare it to the two you have as see what you think- might as well make sure the rest is good before throwing a new piston and cylinder at it.

 

[sean donato]

As it is your first one- maybe 3 hours tops?
But unless you can find good OEM 346 top ends and unless the 351 top end is roached- why bother?
Basically you pull the intake tract and muffler off the cylinder- undo the 4 bolts holding the cylinder down, remove cylinder- remove piston- fit new piston, new cylinder and reverse the rest of the removal stages until you have a complete saw again with no left over major parts.
Get the carb sorted and run the saw- compare it to the two you have as see what you think- might as well make sure the rest is good before throwing a new piston and cylinder at it.

Need to do some minor clearance work so the fins clear the crankcase as well. Make sure to check to see if there is a metal clamp on the intake and not the plastic one while your playing with it. Really it's a good saw how it is and shouldn't be too far behind the 346xp. I vote leave it alone if the top end isn't junk.

 

[born to hunt]

Need to do some minor clearance work so the fins clear the crankcase as well. Make sure to check to see if there is a metal clamp on the intake and not the plastic one while your playing with it. Really it's a good saw how it is and shouldn't be too far behind the 346xp. I vote leave it alone if the top end isn't junk.

Thanks guys- I’ll throw a new carb in it and tune it up. Can’t say enough things about Minnesota Ethanol and carbs. If it were mine it never would’ve seen ethanol. Airplane fuel works great.
Any carb brand recommendations? I’ve had mixed luck with Chinese Amazon specials…

 

[sean donato]

Chainsaw carbs are about the only carbs I rebuild, but honestly it hard to ignore the cheap ones off Amazon and evilbay. Have one on my ms193tc and it works flawless. Couldn't argue with it as $14.00

 

[oldbuzzard]

Before you start go on youtube and look for Husqvarna 346 rebuild (or 353, they are all the same). Top overhauls are relatively simple once you see how they are done. One thing you need to know is on most saws you remove/reinstall the cylinder WITH the intake manifold attached.
While looking at youtube also check out replacing the plastic clamp with the metal clamp. You should do that even if you don’t do anything else to the saw.
Also I agree that new carbs are so cheap they are not worth the time to rebuild.

 

[John Stryker]

If its a fuel problem, I would first check the filter, fuel line, and inspect the carb, and maybe put in a carb kit. Replacing an OEM carb with aftermarket may not necessarily help.

 

[TRTermite]

Before you start go on youtube and look for Husqvarna 346 rebuild (or 353, they are all the same). Top overhauls are relatively simple once you see how they are done. One thing you need to know is on most saws you remove/reinstall the cylinder WITH the intake manifold attached.
While looking at youtube also check out replacing the plastic clamp with the metal clamp. You should do that even if you don’t do anything else to the saw.
Also I agree that new carbs are so cheap they are not worth the time to rebuild.

DITTO on the carb attached and proline has a screw clamp (EBAY) that gives one a secure feeling that all is well with the fit. I forget how many MM it is.

 

[Chevboy0167]

Cheap carbs have been a crap shoot for me. Some were not even drilled out or casted properly. I now buy used OEM of eBay and rebuild. Been working good for me so far.

And yes to the metal intake clamp.... best upgrade to keep these saws alive.

 

[John Lyngdal]

I've had good results with the China carbs on my saws, but once in a while you get a substandard unit. OEM carbs are made in China these days, so OEM products have the extra marking an overhead added to the prices. I tried a 359 carb on one of my 346NE and it just made the adjustment more sensitive.

For sure install a metal clamp, it's cheap insurance against an air leak and possible piston damage if it isn't caught in time.

If a new carb and fuel line gets your 351 back up and running, the cost benefit ratio would be to run it in that configuration.
Even if the piston was toast and the cylinder was in good shape, I'd still install a new piston and correct the issue that lead to the damage leaving the saw as a 351. Finally, if the jug and slug needed to be replaced, I'd rebuild it as a 50cc 346NE.
I like my 346 and 351 Huskys for different reasons, but for average wood cutter there is no functional difference between then. The 346 spins faster but the torque band of the 351 is wider.

 

[macadoodle]

I have a 351, why is it that people want to convert to a 346xp? I know the 346 was a great saw, but what makes it better than a 351? I’m just wondering, I have a very low use 351 and was going to replace the intake clamp, but if I’m doing that I wouldn’t mind changing out the piston and cylinder if I get a better saw. I also just like tinkering!

 

[irhunter]

I have a very low use 351 and was going to replace the intake clamp, but if I’m doing that I wouldn’t mind changing out the piston and cylinder if I get a better saw. I also just like tinkering!

If you want to tinker, I suggest buying a clapped-out 350 for $50 and make that into a xp.

 

[sean donato]

I have a 351, why is it that people want to convert to a 346xp? I know the 346 was a great saw, but what makes it better than a 351? I’m just wondering, I have a very low use 351 and was going to replace the intake clamp, but if I’m doing that I wouldn’t mind changing out the piston and cylinder if I get a better saw. I also just like tinkering!

Totally different saws. Thay happen to share a few common parts. Plastic case vs mag case, different topend ect. Good saws by anymeans, but not close to a 353/346xp.

 

[J D]

Totally different saws. Thay happen to share a few common parts. Plastic case vs mag case, different topend ect. Good saws by anymeans, but not close to a 353/346xp.

351 has a mag case, I think Sean may be referring to the 350?

 

[John Lyngdal]

351 has a mag case, I think Sean may be referring to the 350?

My 351's have a magnesium case.

Back to the OP's question....
If the piston and cylinder on your 351 is in good shape, I don't think that spending ~$130 to replace it with a 346XP NE piston and cylinder is a value proposition. If the top end needed replacement, for sure I would replace it with a 346 upper.
Good plan on your part to replace the plastic clamp.

 

[huskihl]

350 is plastic. Same cylinders as 351 and 353 but with a dished piston

351 is mag case with the same open port cylinder as an early 350

353 is same mag case with a semi closed port cylinder and flat top piston

346 is the same mag case with a bottom fed xp style cylinder. OE was 42mm bore. NE was 44.3mm