Husqvarna 340/351/346 new little snarly wanna be

[KYsawman]

The early 350 was 44mm open port. I always thought the 351 and 353 where 45mm the same closed port cylinder but different pistons. Dished 351 flat 353. The later 350 used the same closed port cylinder as the 351/353 with the removable transfer covers. I guess the did this when they dropped the 351 from the line and to save on parts.

 

[Adamski]

The early 350 was 44mm open port. I always thought the 351 and 353 where 45mm the same closed port cylinder but different pistons. Dished 351 flat 353. The later 350 used the same closed port cylinder as the 351/353 with the removable transfer covers. I guess the did this when they dropped the 351 from the line and to save on parts.

This one has no trans covers.

 

[Tor R]

The only thing you have to keep in mind for your 351G is that it has a different crankcase compared against the one they introduced with the 353.
A 45mm slug is normally a no go, and the case may not accept a 44.3mm piston either.

 

[Adamski]

The only thing you have to keep in mind for your 351G is that it has a different crankcase compared against the one they introduced with the 353.
A 45mm slug is normally a no go, and the case may not accept a 44.3mm piston either.

How do they differ? I assume some grinding of the case can sort this..

 

[Tor R]

How do they differ? I assume some grinding of the case can sort this..

yup, you need to grind the case a bit.
Its the same issue we has with the classic OE case also, none of my 00-01 xpg cases accepted a 44.3mm slug, piston skirt hit the case close to BDC.
There is a service bulletin where it show the difference and on whitch s/n the changes came

 

[old guy]

The 351 uses an open port 44m/m open port cyl. The same as the 350 used for a while, the 353 never used this cyl. The 353 used a 45m/m cyl with a flat top piston, the 350 also used this cyl. With a dished top piston, the 45m/m cyl has the transfer covers.

 

[KYsawman]

I get all the changes in this series confused. They did a lot of mixing and matching. At least a lot of the parts interchange. I have a 340 that is going to get the 346xp(ne) jug and slug and the 350 block. I have a 346xp( ne) and want to compare.

 

[Tor R]

Are those 350 oem blocks still available? And if they are, what part number do your guys order? 2 different blocks as I know about.
I heard they where NLA in Norway

 

[KYsawman]

I bought mine about a year ago 537324001 bearing cup

 

[KYsawman]

Just checked parts tree saying NLA several on eBay 8-24 $

 

[Adamski]

I bought one off Huztl. Fits well so far. Apart from them being wan Khers they are good for a few things

 

[Adamski]

Ideally I would keep both, but which shall I keep and tinker with. This 351G or the 340? Both minty fresh.. but these comments on the 351 case suggest it is not 346 cylinder compatible???

 

[Mattyo]

I have a vid somewhere on the 346xp oe conversion to hyway 45mm top...and where there are clearance issues. I think it was some minor case grinding.

 

[Adamski]

I have a vid somewhere on the 346xp oe conversion to hyway 45mm top...and where there are clearance issues. I think it was some minor case grinding.

So will an old 346oe fit an old 351 case??

 

[Mattyo]

probably...

but what I'm saying is, even a NE will fit... with minimal effort

 

[Tor R]

Ideally I would keep both, but which shall I keep and tinker with. This 351G or the 340? Both minty fresh.. but these comments on the 351 case suggest it is not 346 cylinder compatible???

if you has to pick between them keep the 351, it has a crank&case who is superb compared against the 340/345/350 serie.

So will an old 346oe fit an old 351 case??

oe will fit perfect, its just the ne and a 353 top end that you has to double check the crankcase for.
Ill find the service bulletin for you as fast I'm on my main computer

 

[sunfish]

I'm fixing to go through my brothers 351 & will put a 346 top end on it, not sure OE or NE yet.

Like I've said before, I have put oem NE top ends on three different 346 OE cases with no clearance issues, none were G models if that matters?. There must be some differences between cases?

 

[Tor R]

Not sure if the changes was done around those s/n's:

 

[Adamski]

Not sure if the changes was done around those s/n's:

So material was added to the case around where the piston skirt comes close at bdc. Surely this strengthening was continued through to the new cases. Or was it the opposite, material being removed??

 

[Adamski]

I'm fixing to go through my brothers 351 & will put a 346 top end on it, not sure OE or NE yet.

Like I've said before, I have put oem NE top ends on three different 346 OE cases with no clearance issues, none were G models if that matters?. There must be some differences between cases?

I’m gonna run with the 351. I hope it will be fine like yours were..