What's on your bench today?

[billpierce]

Any help appreciated. Shall I get a 350 piston?

[bmp01]

The plot thickens !

I have nothing to add regarding your question.

So it's definitely been apart before then,  what is the running spec of a 350, ie max speed, speed of max torque

Also, what is that piston? Ring looks very thick, or is it just the picture? 1.5 mm rings found in old pistons and aftermarket lower grade pistons are not good for speeds over 12 k. I would have expected a 346 piston, genuine or Meteor, to be using a 1.2mm ring. Wheres someone with Husky knowledge.... 

 

Edited December 14, 2020 by bmp01

[billpierce]

8 minutes ago, bmp01 said:

The plot thickens !

I have nothing to add regarding your question.

So it's definitely been apart before then,  what is the running spec of a 350, ie max speed, speed of max torque

Also, what is that piston? Ring looks very thick, or is it just the picture? 1.5 mm rings found in old pistons and aftermarket lower grade pistons are not good for speeds over 12 k. I would have expected a 346 piston, genuine or Meteor, to be using a 1.2mm ring. Wheres someone with Husky knowledge.... 

 

It's a mahle piston, perhaps it looks big in that pic, I didnt notice it as being that big before. Ring doesnt look over worn either tbh.

[adw]

1.5 mm ring would be correct, it have started out as a 350, if it has a ser no. plate what does it say?

[bmp01]

2 minutes ago, billpierce said:

It's a mahle piston, perhaps it looks big in that pic, I didnt notice it as being that big before. Ring doesnt look over worn either tbh.

Have you got a vernier to hand, I gotta know......

 

The other thing - if you've still got the 346 carb on there it might not be a good match for a 350 top end, that could explain why you couldn't tune it in.  But again my knowledge of carb sizes / part numbers isnt worth much.  

[Stubby]

2 minutes ago, billpierce said:

It's a mahle piston, perhaps it looks big in that pic, I didnt notice it as being that big before. Ring doesnt look over worn either tbh.

It could be a 353 pot on there . I has one once like that .

[spudulike]

The 346 came in two variants, 45cc and 50cc. The earlier with a 42mm piston, the latter with a weird  sized 44.3mm. The cylinders were always closed transfer ports.

The 350 has open transfers - these will be two channels running up either side of the bore  and a 44mm piston.

It looks like you may have had a previous owner who got hold of one of these top ends and slapped it on. 

I have converted a few 45cc to 50cc 346XPs  and these have worked out well with no issues.

Bit of a strange one and the 350 will not rev anywhere near as high as the 346!

[spudulike]

Just now, Stubby said:

It could be a 353 pot on there . I has one once like that .

Open port transfers on that top end - you can see it in the first pic. Not a 353 unfortunately!

[spudulike]

Take the ring off and pop it in to the bore, push it up square in to the bore with the piston 1" up and measure the ring gap with feeler gauges - that will tell you if the ring is worn. 

Push the piston up in to the bore so the bottom of the skirt is flush with the cylinder bottom and see if there is much rock front to back on the bottom of the piston - a little bit subjective but it works for me!

[bmp01]

Isn't it something like 4 thou clearance piston to cylinder anything over and 'things' is worn ?

 

Thing is,  the piston and cylinder might be fine,  not worn.  The 'problem' is that you were expecting 346xp performance and engine speeds and you're not going to get it with the lower spec 350 top end.

If the saw performs as well as a 350 that would be a surprise with the mismatch of parts. The only other issue was you couldn't tune the carb in - but you might want to review that in light of what you've found since then ?? (Edit - no load speed of 12000 still on low side ?)

 

Sounds to me like you need a 346 cylinder to match that Meteor 346 piston you have ??

 

And your mate owes you some beers for sorting out his PITA saw. 

 

 

 

Edited December 15, 2020 by bmp01
Clarifications plus edit note.