Blown Husky 350...now what?

[Full Chisel]

Hello AS, first time poster. Been reading some prime material here for a while, decided to jump on board. Great site, great info!

Here's the story. I picked up a used 350 off CL a while back, saw started right up no problems, idled good and seemed to run strong. Awesome. Took the saw out later that day because I had some bigger cuts to make that my CS400 couldn't hang with(14"+). Got it out to the site eager to cut with it...pull pull pull until my arm got tired. Nothing. Great. Set the saw aside until the next day when I removed the top cover to find a loose kill switch wire. It had been screwed down between the bolts and thread base, kinda flattened and squishy but I got the saw running by re-attatching it. So the next time I went out to cut, saw ran great. Good power, love how this thing sounds and runs. Well I get home and do my usual cleaning routine. Start it back up to make sure everything is kosher. Idles great, bliped throttle and she goes wiiiiiiide open, throttle released. Hit the kill switch...she's still WO. Choke to kill. Great, I'm immediately thinking air leak issue. Took the saw to the local shop and they fixed the wiring from the coil and everything seemed to check out. So out I go for another round of cutting. Saw runs awesome, no racing, just throwing chips. Idle is a bit off, it wanted to slow down and die after a few mins but nothing concerning. When it died once it started right up one pull. Next time out I had some even bigger cuts to make on the main branch of a giant blown over ~4' Red Oak(the one in my avatar). We're talking 20"+ so the 18" bar was buried and took some patience(I realize now I was pushing the limits of the saw...but that's what I had to work with). The issue is that it was wet out due to a steady light rain and the chain kept getting seized in the bar...lots of mucked up chips in the rail, bar sprocket and drivers. But after a few cleanings and letting the saw cool down the cuts were made and job was done. Got home, cleaned the saws and started it right up. Idled fine. Blip the throttle after letting it warm up for a minute or two and it goes terribly wrong, sounds like coins in a blender. Shut it off before it died, but piston is apparently seized, cord is solid. Haven't looked at it since, very frustrated with the situation because I loved how the saw ran when it was actually running but now I'm out $195. At least it got the job that I bought it for done I guess...

I've never blown a saw up before, so I'm not sure what to expect. Is the clanky, "coins in a blender" noise typical of a top end failure, or am I possibly looking at bottom end issues like blown bearings or something like that? I did not inspect the piston before purchasing it, so I don't know what I was dealing with before it blew up. Saw was run with 93 octane and 50:1 Stihl Ultra full-syn.

I'm looking to purchase a Meteor 45mm closed port P/C kit, but am hesitant to drop almost as much as I have in the saw in top end parts if there are other issues. I really want to get this saw working again.

Any advise is welcome and appreciated.

 

[nmurph]

"Coins in blender" sounds like something came loose. The most common culprit is a wrist pin clip.

 

[Full Chisel]

What's the likelyhood of the top end being salvaged if that is the case? I guess that could mess things up pretty good internally if things got out of place? It sounded bad, I was shocked that I was able to kill it before it died on it's own.

I watched a few videos of disassembly and rebuild on these, but I obviously have little experience in working on saws. How much would I have to take down to see what might be going on internally?

 

[nmurph]

You won't know the extent of the damage until you pull the cylinder. I have seen the tops of pistons that looked like a bulldozer had run over them and the cylinder was fine. I've seen saw with virtually perfect pistons but with cylinders ruin when the clip got caught in the port and then slipped between the piston and the cylinder wall, taking out both. You may be able to pull the muffler and get an idea. Regardless, if something was loose, the saw needs to be opened up and the case flushed well to get the shrapnel out.

 

[Full Chisel]

Great info, thanks for the replies! Any special tools needed to pull the cylinder?

 

[MrGiggles]

Most of those era Husqvarnas are pretty easy to work on... I can completely pull the top end off my 50 in less than 30 minutes.

You will probably need the allen bit for the cylinder base screws, but that's pretty much it. If you don't get a T-handle wrench, you'll have to use a 1/4" drive extension/ratchet and a 1/4" socket to hold a screwdriver bit.

If the saw is still locked up solid, I would pull the muffler, recoil, and spark plug. Rotating the flywheel the opposite of running direction might free it up, and then you can look through the exhaust port to maybe see what failed. You can also peek through the plug hole to see the exhaust-side of the cylinder wall.

 

[Full Chisel]

Good stuff, thanks! Might take it down this evening and get a peek inside. Need to find the little flexible pen light I use for looking down rifle bores...

Will update, hoping for minimal carnage but if it's toast I can look forward to having that big bore, closed port Meteor kit installed. If I'm going to replace the top end I'm going to do it right! No FleaBay junk out of Hong Kong for this guy.

 

[fearofpavement]

Don't freak out yet. It is possible a screw or something came loose and got caught under the flywheel or in the starter mechanism.
Simple to diagnose. Pull the muffler and you will likely have a view of enough of the piston and cylinder if your worst fears are confirmed. Pull the spark plug and look in there too. You can also pull the carb to view the intake side of the piston.

This saw is probably worth repairing regardless of what you find.

 

[fearofpavement]

Pull the recoil starter assembly and you can turn the flywheel by hand in either direction to see what happens. Listen for unpleasant noises and feel for resistance. (pull the spark plug first)

 

[Full Chisel]

This site rocks!

 

[cus_deluxe]

This site rocks!

sure does.

 

[WSE]

Sure hope it turns out for you. 350s are virtually irreplaceable in my book. The new 450s are not what the 350s were. And a new 545 or 550xp is obviously way more costly.

 

[Full Chisel]

Great news, I pulled off the top cover, gave the flywheel a push and low-and-behold there was a loose screw caught in the flywheel! Fearofpavement nailed it. It had come free from the chain brake plate. So easy fix and no seized piston, thank goodness. Speaking of the piston, I pulled out the plug and muffler and the piston looks clean but there looks to be a lot of horizontal scoring on the cylinder wall above the exhaust port. Is that something to be concerned with down the road? It seems to have good compression from the feel of the cord resistance, but I don't have a tester. Haven't tried to start and run it yet...

Also, the cylinder is stamped with "45L"...does that indicate a 45mm top end? This 350 doesn't have the purge bulb. I'm thinking it might be a 350 EPA, can anyone confirm this? Muffler has no cat or any guts to speak of. It is LOUD for a 50cc saw, I really dig it.

 

[Big_Wood]

when it comes the piston scoring i recommend to pull the muffler to check. looking through the plug hole can fool alot of people as depending on which oil your using there could be oil streaks on the cylinder wall making it look to be scored. also, if that cylinder had been cleaned up before but not honed some marks from past scoring may still be present but not be a problem. i would pull the muffler out of curiosity.

 

[Full Chisel]

I did pull the muffler to look at the piston which looks totally clean. But there is definitely horizontal scoring on the exhaust side of the cylinder above the port, it's not oil it's shiny like burrs on a dulled blade. The rest of the cylinder that I can see looks fine. Could the flywheel getting bound up cause chatter in the piston and scoring on the cylinder?

 

[Big_Wood]

no it wouldn't. the marks could be spots where the plating overheated from being scored in the past. as long as the piston isn't getting chewed up i wouldn't worry about it.

 

[Full Chisel]

Cool, thanks! Yeah, the piston looks very clean on the exhaust side. Also, I think it's flat topped and not dished, so it must have been a 353 replacement piston. The CL ad claimed that the saw "only had a few tanks run through it". Those tanks must have been 5 gallon because this saw has been worked over good. But besides for the minor issues with it, so far so good. I just needed something with more power than my trusty CS400 and it has fit the bill nicely for cutting up bigger stuff for firewood.

 

[Marshy]

Do a compression check and let us know what you have for numbers. Also take note of the plug color. Kill the saw in the middle of a cut and check the color. You should see a nice paper bag brown color.

 

[nmurph]

Do a compression check and let us know what you have for numbers. Also take note of the plug color. Kill the saw in the middle of a cut and check the color. You should see a nice paper bag brown color.

There's a lot more to reading a plug than what you've outlined and generally not worth the trouble.

 

[Marshy]

There's a lot more to reading a plug than what you've outlined and generally not worth the trouble.

Agree that it's is more complicated than that but it will give him a warning sign if he pulls it and it's all white (lean). I find it has value for me and use it on all my 2strokes.