pressure and vacuum test for stihl 010av

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redmond ridge

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good sunday morning to all, just want to know if anybody had experienced pressure and vaccum testing a stihl 010av or 011av and the like. i have one that leaks a lot but i can't seem to know where i should connect the hose for the mityvac pressure and vacuum tester. i have taken out the clutch assembly already and the flywheel and connected the mityvac on the sparkplug hole but i can't seem to hold the pressure. i am not really sure if that is where it is supposed to be mounted. would like to hear from you. also, would a small engine like this needs to be checked with squish thing or only on bigger engines?
 
Block the carb, impulse, and exhaust. Testing through the plug hole is fine. Squish check only matters if you remove the cylinder from the saw.
 
thanks for the reply Arrowhead. appreciate it.... i have blocked the carb and the exhaust. thing that i can't find is the impulse line. can't seem to identify it from what is exposed when i have taken out the clutch assembly and the fan. would be glad to know where it should be located. thanks for who would chime in.
 
The impulse opening is through the mounting plate beneath the carb, direct from crankcase into carb. To accurately pressure test these saws, need to remove the carb and this plate and block the crankcase opening underneath, itself.

AS answers 009.jpg
 
thanks stihlsolo..... it looks kind of hard to remove this plate or isn't this the one they call "Reed Valve"? looking at the picture now, i was wondering how i am going to unscrew the nut and if the screw goes round, how to stop it....but somehow, i have to find out a way how to get it out. it's monday again and i might not have so much time to tinker on the saw. have to wait for next weekend. lastly, i have released the cylinder jug to check on the lines on the piston which is very noticeable when i looked at the exhaust side. problem is the crankcase bearing came down loose as it was not a caged. how to i go about to get this back to the crankshaft? is it ok to fill and leave grease on the crankcase just to get the 12 pcs needle bearings in place? didn't realize it will be this tricky to mend this chainsaw. and i am learning the hard way doing this. i just need some guidance. i am not an expert but would like to try on things new to me. i may have to crack open the case if i get lucky looking for the other parts like the 2 needle cage bearings and 2 seals.
 
The reed valve plate is held in place by the 2 long screws that go through the carb and into the crankcase. With the carb off the plate will just lift off. That nut holds the reed valve itself: do not undo that nut.

Don't know of any way to reinstall the bottom end bearings but to split the cases.You can use grease to hold the bearings in place and then flush out with premix after everything is reassembled.

Thought I had posted about reassembly trick on these saws. For reassembly, install the piston and rod into the cylinder, goop up the cylinder bottom plate and gasket and install them, slip the crankshaft through the rod, goop up the bearings and install those. At this point both pieces of the case gasket need to be in place, I use Yamabond.

With everything held steady, install the crankshaft / top end onto one case half. Then install two cylinder bottom bolts into that case half, not fully tight, but tight enough to keep the cylinder in place and allow the other case half to slip over the cylinder bottom gasket. This trick keeps the rod from moving sideways and freeing those bearings. Then install the other case half.

For these saws, if I'm changing anything out in the top end, I use popsicle sticks jammed in through the hole under the reed valve plate into crankcase on both sides of the connecting rod to keep it from moving sideways and freeing those bearings. Then the cylinder can come off. Also learned the hard way about those bearings.
popsicle sticks 001.JPG
 
many thanks again stihlsolo.... it is time to start looking for the case gasket, needle bearings and the oil seal. this will be tedious so might as well renew all there is and put it together in just one go. i hope i can still find parts for this saw. thanks again.
 
FYI, the reed block itself can warp and create a leak. Ask me how I know!
 
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