Husky 350 Testing Help

mdep

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Hi all. I am a new member of the homeowner type and need some help with my Husky 350. I got it new in 2001 and used it occasionally for about 10 years. Then it would't start and also had a leak from the seam of the gas tank handle. So it has been in the basement for 8 years but now I want to fix it if possible. The piston looks like its in pretty good shape on both exhaust and intake sides. the exhaust side has some what looks like rub marks but no scratches or scores.

I read that I might be able to weld the plastic tank with a soldering iron so I will try that if I can verify some other things are OK. The other issues I see are as follows:

1. Compression. I only get about 120 psi with the decompression valve control pulled out (NOT activated) and about 90 psi with it activated, the throttle full open and the muffler installed. I don't know how I could hook up to test the decompression valve and I don't know if there is anything else that matters. I have a HFT compression tester.

2. Cylinder pressure test. I have a MightyVac pressure/vac tester and did the Husqvarna test. It just barely passed. Pressure dropped from 80 Kpa to 60 Kpa in 30 seconds. I think I'd rather find a way to block the intake right at the cylinder rather that at the carburetor. Maybe a clamp between cylinder intake and exhaust with appropriate stops?

3. Carburetor. probably the cause of the original non-starting. I know I would replace fuel line, fuel/air filter and the intake impulse tube but don't know if I should repair or replace the carburetor

So, before going to any disassembly of the cylinder and crank here are my questions:

1. Any tips for compression testing? Any good way to test the decompression valve (or just replace it)?

2. Any better way to test cylinder pressure rather than using the rubber stops at the exhaust and carburetor? Does this test also test the crankcase for leaks?

3. Would I be better off just replacing the carb or repair it? It is a Walbro HDA-159A EPA. Are aftermarket carbs (Amazon) OK?

If I can't get the compression improved will have to move on to inspection of the cylinder/crankcase before addressing the carburetor.

Thanks for any suggestions you can provide.
Mike
 
Huskitoter

Huskitoter

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That's a good saw. Many would repair it, regardless of compression. Low comp is just a good excuse to upgrade it with a 346 cyl. Did the saw run when you stored it?

You will want to uprade the intake boot to the newer style with the metal band when changing hoses.

Check the four cyl cup bolts on the bottom of the saw to make sure none have vibrated loose.
 
cuinrearview

cuinrearview

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I've been on a bit of a 350 kick lately. Very easy saws to work on. To answer your questions:

1. 120psi is good on a 350. The piston is dished and they create very low comp from the factory. Your decomp sounds like it is working properly. If anything I would buy a plug and delete it.

2. That's the best way. Pressurize the case and spray some soapy water around the bottom with the flywheel and clutch/oiler off. They're pretty prone to slight leaks. It can run fine with a little one.

3. I would buy a genuine k22-hda kit and re-build it.

These saws can be torn completely down with a 4 and 5mm t handle, a flat head screwdriver, a hammer, 13mm socket and needle nose pliers in about 15 minutes. The bottom end can be sealed with yamabond, moto-seal, dirko, etc. Bearings and seals are cheap. You could completely overhaul this saw top to bottom for about $50 and a couple of evenings if your piston and cylinder are still good.
 

mdep

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OK so I'll not worry about the compression, for now anyway. I've got a shopping list started and will order the new style metal intake boot clamp right away. I'll concentrate right now on pressurizing and looking for any leaks and loose bolts. I don't know what a dished piston looks like but I noticed by looking in the spark plug hole is that the piston looks flat on top.

I'll report back on the leak searching. Thank you Huskitoter and cuinrearview for your comments. Helped me to have courage to move forward with this 350 instead of just abandoning it again. I think I am gonna learn a lot.
 
grizz55chev

grizz55chev

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OK so I'll not worry about the compression, for now anyway. I've got a shopping list started and will order the new style metal intake boot clamp right away. I'll concentrate right now on pressurizing and looking for any leaks and loose bolts. I don't know what a dished piston looks like but I noticed by looking in the spark plug hole is that the piston looks flat on top.

I'll report back on the leak searching. Thank you Huskitoter and cuinrearview for your comments. Helped me to have courage to move forward with this 350 instead of just abandoning it again. I think I am gonna learn a lot.
The dished piston only comes on the 45 mm epa saw, easily identified by the removable covers on the transfer ports, also written on the top of the jug. A 353 piston is a flat top that will fit right in and give you a nice bump in comp, Meteor is a good aftermarket replacement at a good price, around $40 delivered with Caber rings.
 
cuinrearview

cuinrearview

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The dished piston only comes on the 45 mm epa saw, easily identified by the removable covers on the transfer ports, also written on the top of the jug. A 353 piston is a flat top that will fit right in and give you a nice bump in comp, Meteor is a good aftermarket replacement at a good price, around $40 delivered with Caber rings.
I've put a Hyway pop up in two 350s now. They give a little more of a bump in compression. I would still probably source a caber ring for that piston.
 
Huskitoter

Huskitoter

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That early year should have the 44mm cyl.


I've got a shopping list started and will order the new style metal intake boot clamp

They sell just the metal clamp, but you have to modify the original boot to make it work. Go with a new boot - it only costs a couple more bucks and includes the clamp. Boots age, so it's a good time to change it anyway.
 
grizz55chev

grizz55chev

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That early year should have the 44mm cyl.




They sell just the metal clamp, but you have to modify the original boot to make it work. Go with a new boot - it only costs a couple more bucks and includes the clamp. Boots age, so it's a good time to change it anyway.
That clamp is a pain, go with the clamp off of a 038 Stihl or something comparable.
 

mdep

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OK, OEM K22-HDA rebuild kit, intake boot/clamp, filters, fuel line & filter and impulse tube ordered and to arrive over the next week.
My cylinder (jug?) is stamped with a 44 on it. It is definately a flat topped piston (pop?).

I just remembered (because I'm old) some history of the saw. Had an oiling issue and they replaced the oil pump. Later, it had a leak and they replaced a seal or gasket I think (could've just about bought a new saw for what they charged). All this was 8-9 years ago. It did work after that but then I let it sit too long and it would not start.

Today I pressure tested again and found a leak at the decompression valve. Saw bubbles coming from the two vent holes on the side of the valve. After wetting it , exercising it and blowing air out threw it, it stopped leaking. Did not find any other leaks. Checked seals and all around the flywheel and clutch areas, all around the jug gasket and bolt areas, all around where the crankcase meets the bearing housing and all four bolts on the bottom. Today the pressure dropped from 80 Kpa to 65 Kpa in 30 seconds which passes the Husqvarna test.

I could not use the muffler in the pressure test. The surface where the gasket hits is not flat on the muffler. I think the rubber test stop pushes the muffler metal in except by the bolts. So I used a squeeze type bar clamp to clamp between the exhaust port all the way to the back of the case (fuel tank removed). I blocked the intake as normal, at the carburetor.

I think I can straighten the muffler exhaust flange using a puller. I assume any small exhaust leak is no big deal?

So, now I wait for parts.

I appreciate you chiming in (even if I don't understand all of it:)
Thanks
 

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