Help with McCulloch pro mac 700 vacuum testing

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brandonstc6

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I have a mcculloch pro mac 700 that I rebuilt and it was running way too fast at idle. I work on saws a lot so I bought a mityvac vacuum tester. I am trying to pressure test the saw. I made a block off plate with a fitting to attach a hose. I cut a gasket to go under the block off plate. I then took a piece of gasket material and punched two holes for the muffler bolts then i put it under the muffler and bolted it down. I then tried to pump up pressure and the needle on the gauge didn't move any. I then sprayed soapy water all over the seals and gaskets and around the cylinder base, and around the compression release and spark plug. I did not see any bubbles anywhere. Am I missing something or doing something wrong? ThanksIMG_2991.jpgIMG_2992.jpg
 
there is a pump housing undet the gas tank. i think it runs the oil pump off comression need to take take off and see. look above oil tank plug under gas tank
 
I sprayed soapy water around it and didn't see any leaks. Tomorrow I will try removing the compression release and plug the hole. If that don't work, then I will check the oil pump but everything looked good there when I had it apart.
 
this engine is a sump set up there is no case to split. you might have to keep spraying soap water and keep pumping to you need bubbles.
 
see the hole in line with compress release and above the muffler have you tried spraying there that is where the com release can leak
 
I got the compression release blocked off and I checked the oiler and the bolt holes and I cannot find the leak. What else can I do?
 
pull the flywheel and points and then fill up you wheel barrow and dunk the saw. i have had to do that before. did you check the oil pump. also need to check the line that is hooked to the mity vac
 
Check to see if it will hold a vacuum. If you do the dunk test make sure you are ready to run it soon. Dunked one of my PM800s, didn't get back to it soon enough - now needs bearings due to the trapped moisture.

I will point out your thread in the MAC sticky - those guys have yellow blood.

Ron
 
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