Air leak

[piglosi]

In process top end rebuild complete and I have an air leak. Looking at the green cylinder gasket on the exhaust side, the edges of the gasket appear wavy. I think this is the issue. I either honked up the gasket, or it’s a POS. The gasket appeared centered and all fastener holes looked good when I stuck it down. This is a LRB gasket from eBay. The NOS homelite gaskets I used on the other 2 EZ’s are fine, sit flat, no wave, and tuned well. I ordered a couple gaskets from Randy. Don’t want to cook my new piston I got from Leon.

Metering lever is correct height in carb. Base gasket is new and fine. Saw will start and idle, but ya get nothing until the adjustment screws are about 2.5 turns out and it sounds lean. Couple throttle hits, and it won’t hold that rich tune and leans out.

[piglosi]

My problem is not the gasket from little red barn. The homelite gasket fit better, used no sealant to hold in place, but saw exhibits same issue. Will start and idle, but flat out bog when you hit the throttle. Metering lever is flush with the casting, gaskets and diaphragms are in correct location, and hi/low screws are 1.25 out. Gasket is good. No visible cracks to intake and it’s tight. Drive case is tight. Piston and rings are new and installed correctly. IDK, will a bad crank seal act this way? I’ve never done one on an SEZ but I may learn soon!

[piglosi]

I be had the carb off this saw 1/2 dozen times. If I don’t crack the gas cap, when I pop the fuel line off the carb inlet nip, it will fill the box with fuel. Is this normal? I rebuilt the cap.

[blythkd]

Normal for gas to flow out of the disconnected fuel line. Any time I'm going to remove a carb I either drain the tank first or plug off the fuel line with a small screwdriver or punch or something.

Have you tip tested it? Get it idling and tip it so the crankshaft is vertical to one side then the other to see if the idle changes. It's about the best test for bad crank seals there is other than pressurizing the case and dunking the saw which is a lot more involved.

[piglosi]

I didn’t tip test it, but that’s a good idea. It will idle a bit. Hit throttle and it’s like chain brake is engaged. Got clutch and oil pump off now.

[piglosi]

Thank you for the help. BTW, where is the crank seal on the clutch side? All I see is the bearing sticking out 1/8” into the drive case and the oil pump fits over it. IPL not much help.

[piglosi]

I see it, used a real narrow pointy knife and tapped it right out. New one went in, however I am below flush with drivecase. Is that ok? About .100.
Clutch back on, fired saw up and it runs, however clutch is always engaged. This is the 3 shoe clutch. Hmmmm

[piglosi]

Swapped carbs and it runs the same, lean. Hit the drivecase with carb clean while running and no change. Shot the carb adapter area and she died. Restarted, repeat spray died. That’s probably the problem. Anyone else have problems with leaks in that area? Carb adapter or reed block?

[piglosi]

Swapped carb adapters and gaskets from a parts saw and same thing. I’m still sucking air from somewhere around there. If I dribble carb spray saw picks up some. If I juice it good, she quits. Anyone struggle with an air leak in this area?
I didn’t see any damage to the carb block or gasket, besides the dimples on the gasket from reed pyramid. I’m a bit stumped.
At least I learned PTO side crank seal today.

[blythkd]

That manifold that the carb bolts to has been a common piece to find cracked. Could be you have 2 broken ones. They crack near the screw bosses. Other than that, not sure. Could be a crack in the crankcase I suppose. If you can't find it you might have to pressurize the case and run some soapy water over the area where the leak is.

I don't typically drive those seals down into the drive case but I doubt that it hurts anything as long as the rubber part of the seal isn't down against the bearing race.

[piglosi]

Thank you for taking the time to reply.
I am gonna pull the handle off and have a good look at the intake system. I didn’t see any cracks visually but I do NDT inspection and maybe fpi will reveal something. I will focus on the crankcase too.
I like these SEZ saws. My FIL turned me into em a decade ago when I ran the one he bought with a whole paycheck back in ‘78. They are worth fixing. Growing up I worked firewood with my father. He ran a fleet of mini macs and super 2’s. Largest bar was 16 lp chain. We were poor and he liked the lightweight saw. The macs are tough and time consuming ti work on. The homelite was better. Once I got a paying job, I bought a Husky 51 from a shop, tuned it for 32:1, and got the work done faster. Still have it, 25 yrs old, at least 100 cord cut, original piston looks factory through ex port. Knock on wood. I love these homelites now in our throwaway China world.
When I fix this thing I will report back the root problem.

[piglosi]

Problem solved. There is a square black flexible pc (no part number but stamped 16)that retains the reeds to the pyramid that fits in the intake portion of the crankcase. The inside radius of it was cracked 360 around. Reed pyramid from parts saw didn’t have the crack so in it went. Cleaned up the crankcase surface of corrosion and oil and it runs great. Using carb clean to find an air leak works and I hope I remember this. Thanks for the help.

[blythkd]

Funny, I almost mentioned checking that rubber retainer since it doubles as a gasket but then I thought, nah, there's never anything wrong with them. Just goes to show, the more time goes on, the more different issues we see, sometimes even with parts that have never been an issue.

Glad you got it fixed. It just takes persistence.

[piglosi]

Yeah, I had to look close up with 10x. Couldn’t see it cracked until you flexed it. I’m gonna look around for a NOS one for backup. Thanks for the help again.

[piglosi]

Part number is 65011. Few NOS on eBay for 7-8$

[piglosi]

Leon got em.