Thats pretty good info there never knew that! Ive always made sure i have mixed my oil 40:1 using synthetic but i guess i should start using and adding more oil to my gas. I wonder if the oil technology has improved so much since then is to why all the manufactures require 50:1 mix or they are just trying just trying to screw us so our saws will tear up and we have to buy new ones haha? So doing those upgrades i should be completly fine and my saw be fine as long as its done right?
I would not suggest running any of the new saws on newly formulated oil at a 15:1, or even 20:1. I know some run at 32:1,
but you better be watching what oil your using. Personally in a stock newer saw that was not ported I would not run anything more than 40:1(some may disagree).
On that 55 husky I would run a 91 or 93 and 40:1, tune it and be done as far as the oil and fuel go.
As
@Nanuq said, you have to figure out how fast you want to make it, there are always trade offs. Thanks Nanuq for posting that great old school picture as well as mentioning the coolest bike race there is(Just watched about 20 IOM videos tonight lol).
Just opening up the muffler will cause the saw to be louder, is that something your willing to deal with.
Porting will make it faster, but that cost some bucks, how much are you wanting to spend.
Personally I'd sell the 55(unless there it was a gift or family members), and then buy a ported saw. Another option is to go for the 2 saw plan, if you don't already have a few(you will soon if you hang out here much
), but what fun would having only two saws be
.
As far as switching to a closed port cylinder I think the gains will be minimal at best, last I knew you could not buy an oe replacement piston for them either. If you are going to advance the timing you should know how far you are advancing it in degrees. Do you know how to check the squish on a saw, it's a good idea when removing the base gaskets/cutting the base.
Before doing any changes you should document some test cuts so that after you make changes you have a baseline to compare the modded saw to. A saw with a muffler mod may sound faster, but how will you know if it really is.
Have fun
.