#1 this one is just coursity. The crank case ports has anyone done anything to them? Like the little section of gasket. Would cutting that open it up any? Ive noticed it's not connected to the lowers divider. unlike divider in a 372 boot.
Okay for the question that's most important. what or how do we clean the injector? I didn't see that in the service manual. I could have completely missed it. My Minds been running a million miles on empty as of late, so I apologize if I've missed that part! I've got two types of injector cleaners (a 12v that you press onto a can of carb clean and a multi injector machine) but I don't know if there's an adapter or something to make either fit.
Report back on #1 if you do it. I’ve been tempted but left it alone. Across several Stihl Models. Because it isn’t continuous to the cylinder it seems like it would create turbulence. But it’s very far from the uppers. It may serve to organize turbulence from the case earlier in the transfer tract. The not so secret sauce to the front fed transfers is how well they aim the flow of the uppers. Anything that makes that flow more linear is good. IIRC, Husky 5 series does not have a gasket piece in the case lowers. Maybe someone can confirm that.
Don’t clean the injector unless you know it’s dirty. In that case you’re probably in for a new one so what can it hurt? Standard carb cleaner or Ethanol are probably better than proprietary injector cleaners designed for automotive.
You may be able to pump from the primer through the injector while the parts are off the saw. I can’t remember if the injector piston will open during that process. If not you may have to rig up a battery system to activate the injector (best guess is it’s 4.5-6V system). That avoids introducing cleaning agents into the rest of the saw.
Whatever cleaner you use, don’t soak it. Just pump some through and then get non-ethanol mix back into the system. That should preserve the rubber parts best. Most rubber degrades from ethanol bonding to ambient moisture over time not from short term exposure.
The CPU may tell you the injector is bad in certain circumstances, but it has extremely limited capabilities. My injector did not read as bad even though fuel was actively dripping out of the vent. I would not rely on it for diagnostics. Standard trouble shooting is necessary.
Great saws but parts costs add up quickly. It really helps to have a known, good, stock saw to swap parts with. That’s basically what the dealers do. The MDG1 system is a huge disappointment. It makes the saws software dependent for resets but does extremely little for diagnosis.
Take anything I say with several grains of salt. Almost all my 500i experience is with one saw. It was a 2 year saga to get it running and I replaced and messed with almost every component of the saw. In the end, the problem was a rare one. I had a bad stator wire, the injector was probably broken from excessive priming. Vapor lock/hard restarts are more common than my problem. If that’s what you’re dealing with I’m not much help.
