Husky 350 rebuild.
I was looking to up grade from the Homlite Timberman which I had been using lately. Since I only cut a few cords for firewood I couldn’t really justify purchasing a brand new saw. I thought it would be interesting project to rebuild a non runner.
I found a non running Husky 350 on CL for $50, the saw looked to be in good shape other than it had almost no compression.. I figures I would give it a shot and see if I could get it running again.
I removed the cylinder, and as expected the piston was toast. After reading about cylinder reconditioning on this site, I used muriatic acid and sandpaper to remove the aluminum from the cylinder bore. The cylinder cleaned up fairly well, except for one spot that was a little questionable. There was a bit of a groove that you could feel. I used a dremel with a scotch brite wheel to blend and polish as best I could.
I ordered a piston and ring kit form eBay; I think it was about $25 shipped. I put the top end on and figured it would be a good idea to check for air leaks. Again using good information from this site, I ordered a cheap vacuum tester form Harbor freight. I blocked off the intake and exhaust with some rubber gasket material and tried to pull vacuum. The engine would not hold vacuum at all. I then used my home made leak-down tester to try and find the leak, I sprayed soapy water on the engine, and sure enough there was a sizable air leak where the aluminum crankcase attaches to the plastic crankcase. I suspect what happens is the plastic relaxed a bit causing the joint to loosen.
So I took it all apart, cleaned up everything, I used a surface plate with some fine sandpaper to resurface the aluminum crankcase. When I reassembled the engine I used Halomar gasket sealer, the stuff is quite expensive ($10/ tube) but it is supposed to be good stuff. I also got rid of that lousy plastic clamp on the intake manifold and replaced it with a hose clamp. I reassembled the engine and tried the vacuum test again, and what do you know it held vacuum very well, crank seals seemed fine.
I replaced the fuel line (it had some cracks) and filter, and replaced the diaphragms in the carb. I cut the plastic carb limiter caps with an exacto knife to allow proper adjustment.
I did a compression test and it was about 120psi, a little on the low side, probably due to the cylinder wear.
I used a drill press with a grinding stone to grind the bar square and then filed off the burs.
Now the real test will it run? I put some mix in it started right up. I adjusted the carb to get it running well. I used for about a half hour and cut a few logs; the saw ran well and cut quite nicely.
I rechecked the compression and it did increase a bit, it is now about 130 psi, perhaps it will increase some more when it’s fully broken in.
This was my first major saw rebuild, I have rebuilt many dirt bike engines when I was younger, so I am not a total beginner. All in all I would say this was a success. Thanks to all the great tips and info on this site.
I was looking to up grade from the Homlite Timberman which I had been using lately. Since I only cut a few cords for firewood I couldn’t really justify purchasing a brand new saw. I thought it would be interesting project to rebuild a non runner.
I found a non running Husky 350 on CL for $50, the saw looked to be in good shape other than it had almost no compression.. I figures I would give it a shot and see if I could get it running again.
I removed the cylinder, and as expected the piston was toast. After reading about cylinder reconditioning on this site, I used muriatic acid and sandpaper to remove the aluminum from the cylinder bore. The cylinder cleaned up fairly well, except for one spot that was a little questionable. There was a bit of a groove that you could feel. I used a dremel with a scotch brite wheel to blend and polish as best I could.
I ordered a piston and ring kit form eBay; I think it was about $25 shipped. I put the top end on and figured it would be a good idea to check for air leaks. Again using good information from this site, I ordered a cheap vacuum tester form Harbor freight. I blocked off the intake and exhaust with some rubber gasket material and tried to pull vacuum. The engine would not hold vacuum at all. I then used my home made leak-down tester to try and find the leak, I sprayed soapy water on the engine, and sure enough there was a sizable air leak where the aluminum crankcase attaches to the plastic crankcase. I suspect what happens is the plastic relaxed a bit causing the joint to loosen.
So I took it all apart, cleaned up everything, I used a surface plate with some fine sandpaper to resurface the aluminum crankcase. When I reassembled the engine I used Halomar gasket sealer, the stuff is quite expensive ($10/ tube) but it is supposed to be good stuff. I also got rid of that lousy plastic clamp on the intake manifold and replaced it with a hose clamp. I reassembled the engine and tried the vacuum test again, and what do you know it held vacuum very well, crank seals seemed fine.
I replaced the fuel line (it had some cracks) and filter, and replaced the diaphragms in the carb. I cut the plastic carb limiter caps with an exacto knife to allow proper adjustment.
I did a compression test and it was about 120psi, a little on the low side, probably due to the cylinder wear.
I used a drill press with a grinding stone to grind the bar square and then filed off the burs.
Now the real test will it run? I put some mix in it started right up. I adjusted the carb to get it running well. I used for about a half hour and cut a few logs; the saw ran well and cut quite nicely.
I rechecked the compression and it did increase a bit, it is now about 130 psi, perhaps it will increase some more when it’s fully broken in.
This was my first major saw rebuild, I have rebuilt many dirt bike engines when I was younger, so I am not a total beginner. All in all I would say this was a success. Thanks to all the great tips and info on this site.
