acquired a jonsered 451E saw. Love how it was built and runs but couldnt be tuned
Tore it down and did a vacuum and pressure test. Squirt soapy solution all over. Aha! The pto seal leaking. Replace seal. Run tests again and still leaking. Spray soap again. Its the freaking modified spark plug; not where i installed the quick coupler into the plug base but where the plug screws into the cylinder. What? Took it out and saw some divits on the mating surface. Filed them down, reinstalled, and pressurized. Problem fixed. Holds vacuum (5 psi for 5 minutes) and pressure (10 psi). Reassemble saw and test cut. Still cant tune. Im thinking its probly the other seal so i tear it down and replace the other seal. Do some cutting and voila! same symptons. Dam. Tear it down and run tests again. Almost holds vacuum but very slowly loses vacuum; after 3 minutes lost 2psi of the 5psi i started at. Neither seal is leaking. Neither is the plug. Start sprayng everywhere. Its the freaking cylinder gasket. Three of the cylinder bolts are tight, one not loose but not even close to spec. Took it apart AGAIN and noticed the three tight bolts have noticeable thread lock and the other does not; someone screwed up. Ordered new gasket. Waiting for delivery. Will let you know how it works out.
What ive learned is to think outside the box.
Tore it down and did a vacuum and pressure test. Squirt soapy solution all over. Aha! The pto seal leaking. Replace seal. Run tests again and still leaking. Spray soap again. Its the freaking modified spark plug; not where i installed the quick coupler into the plug base but where the plug screws into the cylinder. What? Took it out and saw some divits on the mating surface. Filed them down, reinstalled, and pressurized. Problem fixed. Holds vacuum (5 psi for 5 minutes) and pressure (10 psi). Reassemble saw and test cut. Still cant tune. Im thinking its probly the other seal so i tear it down and replace the other seal. Do some cutting and voila! same symptons. Dam. Tear it down and run tests again. Almost holds vacuum but very slowly loses vacuum; after 3 minutes lost 2psi of the 5psi i started at. Neither seal is leaking. Neither is the plug. Start sprayng everywhere. Its the freaking cylinder gasket. Three of the cylinder bolts are tight, one not loose but not even close to spec. Took it apart AGAIN and noticed the three tight bolts have noticeable thread lock and the other does not; someone screwed up. Ordered new gasket. Waiting for delivery. Will let you know how it works out.
What ive learned is to think outside the box.
