Pressure test them.
Ignition Coil Or Gas Issue, I think
- Thread starter Isidro
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I put a vacuum on the fuel line and it held. the line looked really good. I do have an extra fuel line so I might just change it out. Today I am going to focus on pressure testing the saw body, sealing off the carb and muffler. I got to rule that out as the cause for no back pressure to the carb. There is not enough suck to move fuel into the carb while it is running. I do have a leak somewhere that I got to find. At this point I can not let that saw "win" Might end up with a total rebuild which could equal the cost of a new saw but I will learn a lot and it will keep my out of the bars.
Vac test the impulse port or line and see if it shakes the needle back and forth while pulling it over .
I have one to do tomorrow also.
Today I pressure tested the saw's body. Blocked the carb side and the muffler side. The pressure is holding at 10 psi for over an hour now. That is good news. Right now all signs point to the impulse lines and connections. Will wait for my new part and then update.
Tony
good luck
Not sure what you are thinking is supposed to be happening here. Back pressure to a carb???
Yes, I am expecting back pressure to the carb. I do not see any, the saw starts but does not stay running.
I order the part that you attached in your reply. I have check my existing unit and I find no leaks when I put a vacuum on that small hose. I think the carb connection to the line is weak and/or the surface to surface connection on the other end of the line is not "seating" well enough to support a vacuum so no fuel is being sucked into the carb. Hopefully, the new part will eliminate either or both those problems and the saw stays running. If not I am really challenged as to what is causing my problem.
Thank you for responding to my posts, I need all the help I can get.
Tony
You are not looking for constant pressure back to the carburetor
what you want is a pulse signal - when the piston moves up It sucks a vacuum on the impulse tube and when the piston moves down it pushes of pressure wave into the tube
This back-and-forth pressure causes the rubber diaphragm in the carburetor to pump fuel which is what keeps your saw running
Yup just put a vac tester on it and it should flutter back and forth.
I agree, will check for that movement with gauge and let you know. Thank you
I still need to hock up a vac tester and see if I get back and forth movement. Tomorrow I am going fishing but I got the rest of the week to check that out. I will let you know what I find out. Thank you, Tony
I installed a new flange and the problem still exist. Monday I am going to focus on the spark and coil. I do not think there is any more I can do related to the fuel delivery system
Wish me luck, Tony
Wish me luck, Tony
I hope I made a break through. I have no spark at high RPMs. I do have a constant spark at low RPMs. I order a new OEM coil which I hope solves my very frustrating problem. I ran to the ground every gas related component on my saw and nothing. I pulled the pull cord off, connected a trouble light to the spark plug, ran the saw with a drill, and got spark at low RPMs but not at high RPMs. Sure hope a new coil solves my problem. We shall see.
Again, thank you for all your help, Tony
Again, thank you for all your help, Tony
Received and installed the new coil. The saw started right up and remained running. Just need to adjust the carb. I am confident I, we, got my problem solved. The free saw was still a great deal and now I have a few extra parts that in the end were not the issue or bad. I did have a bad coil which I tossed.
Thank you and everyone who waded to help solve my saw issue. Learned a lot and had fun doing it.
Tony
Thank you and everyone who waded to help solve my saw issue. Learned a lot and had fun doing it.
Tony
Thanks for getting back to us with the solution, too often we never know if any of our advice helped. That's strange behavior for a coil so kind of put it on the "not likely" list, but with the electronic package in modern coils, strange things do happen. Good on you for sticking with it.
