Woody Longbranch
ArboristSite Member
There is pressure in the fuel tank proportionate to the rpm. With a good vent attached,( i checked it on another saw) the pressure causes a good fuel cap, ( i checked it on another saw) to leak, not at idle but more the higher the rpms. Take the vent off the long hose ms 390 style and fue pumps out the hose.
Yes I had the saw apart, when i put it back together I didn't tighten the knot on the flywheel and it backed off and it sheared the built in key. But I went to stop the saw after that happened I saw the Piston wasn't going up and down and I thought I broke the connecting rod for some of the internal mechanical failure cuz I had replaced the Piston maybe the clip came off the end of the wrist pain and broke the wrist pin or the Piston skirt broke.
But no it was just the Woodruff key thing so I put another flywheel on and put the motor back together and that's when the problems started so I'm thinking I didn't get the seals seated properly and that the leaking but someone must know that has to be one specific reason that pressure is building up inside the gas tank proportionate with the RPMs it's not the vent and it's not the gas cap it's pressure building up in the tank and the motor has been recently a apart.
The saw runs really really strong with the new piston and cylinder.
I let one of my ground guys use it to cut up the big limbs when they go out on the ground cuz the limbs were too big for a small saw but it's spraying gas inside the cover where vent hoses is . My question is does anybody know what is causing this? What will fix this?
I did try to search all the threads on the chainsaw to see if anybody talked about it I'm sure it's happened to other people but I couldn't find a thread that talked about pressure coming out the vent of the gas cap except for the threads that identified bad gas caps or bad vents and this is neither.
Thanku
Yes I had the saw apart, when i put it back together I didn't tighten the knot on the flywheel and it backed off and it sheared the built in key. But I went to stop the saw after that happened I saw the Piston wasn't going up and down and I thought I broke the connecting rod for some of the internal mechanical failure cuz I had replaced the Piston maybe the clip came off the end of the wrist pain and broke the wrist pin or the Piston skirt broke.
But no it was just the Woodruff key thing so I put another flywheel on and put the motor back together and that's when the problems started so I'm thinking I didn't get the seals seated properly and that the leaking but someone must know that has to be one specific reason that pressure is building up inside the gas tank proportionate with the RPMs it's not the vent and it's not the gas cap it's pressure building up in the tank and the motor has been recently a apart.
The saw runs really really strong with the new piston and cylinder.
I let one of my ground guys use it to cut up the big limbs when they go out on the ground cuz the limbs were too big for a small saw but it's spraying gas inside the cover where vent hoses is . My question is does anybody know what is causing this? What will fix this?
I did try to search all the threads on the chainsaw to see if anybody talked about it I'm sure it's happened to other people but I couldn't find a thread that talked about pressure coming out the vent of the gas cap except for the threads that identified bad gas caps or bad vents and this is neither.
Thanku
