Thanks for the tip on the 5020! Now if I could only come up with a system to start it. Sometimes it's a bear.
I know this is a stupid question, but what is a "Strato" I know I love how the 2050 runs when I've got it wide open, kind of like running on nitro. Is that something I should be looking for in other saws?
My back has been toast since my last motorcycle wreck so even if I were to use a 10" chainsaw, my back would still complain. So I give it something to really complain about using the 20". :msp_scared: As long as it's fairly well balanced, I'm good to go. :msp_biggrin:
Overkill is using a 115cc chainsaw with a 60 inch bar n chain (if there is such an animal) on a 6 inch sapling! But just think of the ground you could cover if you had a field of 6 inch sapplings! :msp_w00t: Not that I could even lift a chainsaw that big, but if I'm going to dream, I might as well dream big.
Starting: I'd suggest pulling gently until engaged, then rip on that thing like your life depended on it, for a
short stroke. Don't want to destroy the starter reel. Of course, thoroughly purge carb air first.
Strato (as commonly done):
background: port openings are symmetric about bottom dead center. As things turn, exhaust opens, transfers open, transfers close, exhaust closes. So exhaust is open all the while the transfers are open, and in spite of mfgs best efforts, much incoming charge "short-circuits" right out the pipe. Nasty, waste of fuel. Makes engine waaaay out of emissions compliance, and tosses away around 35% of the fuel.
Strato engine: besides the usual air&fuel carb port, there are variably throttled air-only ports connected to the filter. As the piston approaches top dead center, cutaways in the sides of the piston skirt connect the air-only ports to the discharge end of the transfers. So, what'll come out first there (and may go out the exhaust) is air and no fuel/oil.
You'll see some of the mechanism involved if you look at an IPL (Illustrated Parts List) of a strato saw, and zoom in on the piston. Crystal clear in the IPL for RedMax GZ4000.
This "strato scavenging" greatly reduced HC and particulates (think carcinogens) emissions, and reduced fuel consumption. The improvement in air quality local to the saw is huge, such that I won't consider buying a non-strato 2-stroke. RedMax (div Komatsu Zenoah) developed it, Husqvarna bought RedMax from Komatsu, and later the EU folks strong-armed Husqy to license the technology to Stihl, or so one story goes.
Pardon any avoidable surplusage; I tried for the "just the facts" treatment.
Subject merits completeness.
Absent direct injection (into the chamber) it's THE way to control emissions without stupid factory modifications. Lots more stuff to fail with direct injection, which is not to claim diaphragm carbs are trivially simple.
I yield the podium to any engineers involved in the process, to set us straight(er).
