Thanks, you guys have filled in some of the blanks. But I still don't have a clear picture of why all of the Husky 51/55 jugs have that threaded hole in them. Maybe another way to ask this is were there any Partner models that used those same open port cylinders? Seems like most of the small Partners aside from the P400 family were closed port designs.
The P540 and P543 used the same open port 46mm jugs as the 55.
Otherwise, those saws were related to the P500/P5000. :msp_wink:
The Formula 500 partner I had was a open port 45mm.
It wouldn't surprice me if it is tha same as the 51 usually used.
Like SawTroll said the 540 and 543 used the exact same open port top end as the Husky 55
The 45mm Formula 500 top end is the same top as a Husky 51.
Spike without going into deep details like dates etc, just remember that Elux raped, robbed and pillaged its accusitions back in those days. The 500 design predates the Husky 50/51/55 saws, so its plain to see that Elux just used a good cylinder design that Partner already had when it came time for them to design there saws. Thats why the Husky cyls had that threaded hole in them, they are based on a Partner cyl design.
Same with the handle designs on the Jreds etc. You have to remember that Elux wanted Husqvarna to be the top dog in there holdings and Husqvarna saws would probably not be what they are today if it were not for Partner, Poulan, Jonsereds,Pioneer etc. Its just business.
You have to remember that we only see what goes on here in North America and that were not the only place Husqvarna does business. Parts used for one saw here might end up on something else overseas so maybet that threaded hole is used on something else.
Spike, here is a picture of the cyl on my Partner 540. You can see where the threaded hole is used on the Partner, but look close and you can see the boss for the decomp that cannot be used on the Partner but its still there anyway.
A shot from the other side should look familiar to you.