Chainsaw Repair

4219 T-WRENCH CHAINSAWS SPARK PLUGS 16MM X 13MM HUSQVARNA   found it bought in march 2013. 

Owner's manuals that come with the saws state 3.4 and 3.8 HP for the "new kids". Porting is different, but I suspect it has to do with the port covers as on the 365/372 XT's. (Not sure cause I haven't looked).

The saws share the same piston, carb, AT module and software program. Only the coils are different. Revboost is obviously one item, but there may be more to it.

According to a recent post on the AS by Randy (Mastermind) the top ends are exactly the same, despite the part numbers are different?   

That ignition coil for the 550XP costs $61

Don't forget the full circle crank adapter as a difference too.

Of course, but that isn't what the confusion is about - it is about the cylinder, or rather the transfer covers.

I have both saws and early on took the covers off and compared numbers. The casting number on the transfers are the same

Looks like the different part numbers on the complete assamblys is a deception then, as all the other part numbers are the same?

That brings us back to the coils and the crank stuffers being the only real differences - and maybe the software? Does that really make sense? 

Of course it really is about how they chose to make the power output lower on the non-xp version, not at all about making the output of the xp as high as possible - as usual.

It is a bit odd that they did it in a different way on the 50cc saws than they did on the very similar 60cc ones though - and that the part numbers are different on the same cylinder/transfer covers.