Rein
ArboristSite Member
UPDATE: I posted this on 3 Facebook groups and 3 members of the
Dolmar Chainsaws and Makita Power Equipment group all said the same thing - these saws are know for having (or developing) weak springs and the solution is to install a stronger needle valve return spring. A couple people have agreed with the tank vent idea, but since I experienced no change in pressure when I loosened the fuel cap I am not confident the vent is the issue. Now all i have to do is figure out what a "stiffer" spring is! I'll probably just get a carb rebuilt kit so I
I worked on this saw recently and there were a lot of things I needed to address in addition to the owner request to replace the AV system and check into it being difficult to restart once it was warm. As I removed the fuel lines from the carb in preparation for cleaning, fuel spurted out the intake line. I immediately loosened the fuel tank cap but fuel continued to come out so I clamped the line off temporarily while I worked on other things. Once I had the carb cleaned I reattached the fuel lines and that one line still had pressure in it. Later on I did empty the tank, flush out with fresh fuel, blow it out and blow out the filter. I eventually got the saw running and tuned well and fixed the other issues. I had it in my shop for several days after working on it and it seemed fine, with no smell of fuel. Today I got a call that fuel is “dripping” out of the muffler. The customer has yet to fire the saw up. Is it possible that the fuel tank vent is clogged and the inlet line is expanding with fuel and releasing it over time? The only other thing I can think of is the carb metering diaphragm is pressing on the needle valve lever and releasing fuel somehow. The thing is, when I was done with this saw it started cold or warm easily, idled around 2500 RPM and maxed out at around 13,000 RPM (I didn’t want to allow it to max out at the spec of 13,500). It didn’t react the way a flooded saw would at all.
Dolmar Chainsaws and Makita Power Equipment group all said the same thing - these saws are know for having (or developing) weak springs and the solution is to install a stronger needle valve return spring. A couple people have agreed with the tank vent idea, but since I experienced no change in pressure when I loosened the fuel cap I am not confident the vent is the issue. Now all i have to do is figure out what a "stiffer" spring is! I'll probably just get a carb rebuilt kit so I
I worked on this saw recently and there were a lot of things I needed to address in addition to the owner request to replace the AV system and check into it being difficult to restart once it was warm. As I removed the fuel lines from the carb in preparation for cleaning, fuel spurted out the intake line. I immediately loosened the fuel tank cap but fuel continued to come out so I clamped the line off temporarily while I worked on other things. Once I had the carb cleaned I reattached the fuel lines and that one line still had pressure in it. Later on I did empty the tank, flush out with fresh fuel, blow it out and blow out the filter. I eventually got the saw running and tuned well and fixed the other issues. I had it in my shop for several days after working on it and it seemed fine, with no smell of fuel. Today I got a call that fuel is “dripping” out of the muffler. The customer has yet to fire the saw up. Is it possible that the fuel tank vent is clogged and the inlet line is expanding with fuel and releasing it over time? The only other thing I can think of is the carb metering diaphragm is pressing on the needle valve lever and releasing fuel somehow. The thing is, when I was done with this saw it started cold or warm easily, idled around 2500 RPM and maxed out at around 13,000 RPM (I didn’t want to allow it to max out at the spec of 13,500). It didn’t react the way a flooded saw would at all.
