I know this is an old thread, but just wanted to pass along some info if anyone else stumbles on this issue.
I picked up a Montgomery Ward 3.6 chainsaw last weekend which is just a rebranded Remington PL4. It had the original fuel line on it (had factory overspray on it) and I had to cut it to get it off the carb and fitting in the handle. I thought I was going to have to dismantle the saw too, but I was able to fit some tygon fuel line through the hole in the carb tray up to the fitting that comes out of the tank inside the handle.
If you heat up the tygon line really hot (I stuck it inside the heat vent of my truck for a few minutes with the heat on high), and then apply some oil around the fitting and on the part of the line you're sticking on, you can fit it through the hole up to the fitting and get it started by just pushing it slightly. Then you can get some needle nose pliers and get in there to pull it onto the fitting. It's not easy but it can be done.
Then when you put the carb back in, you just have to do some test fitting as to how far to trim the line back to fit on the inlet of the carb without being too long or short.
The new line is not leaking and the saw is running great again. Hope this helps someone down the road.