Muffler falling off (again) Husky 350

[pen]

About a year ago I had the threads for the muffler bolts give out on my husky 350. Helicoils were installed and bolted things back up. With the repair freshly done, I spot welded the bolt heads to the muffler so that they couldn't back out. That worked for about 6 cord of wood, and now the helicoils are stripped out (tack welds held).

I wish like heck I tried to find or make studs instead of re-using factory exhaust bolts but hindsight is 20/20.

Any suggestions on what to do next with the darn thing? Saw runs 100% so I hate to give up on it but really want to fix it so it holds as it should.

Thanks guys,

pen

 

[JOHN BOY]

I have the same saw , its tough as a pine knot. It fell off twice. Believe it or not ive Ported the muffler to help the saw run cooler. I used red loc-tite in the threads and have not had a problem
You could tap the holes larger to fit bigger bolts ,of course you'd have to open up the muffler holes to.

 

[clemsonfor]

I was thinking retap to a larger size and drill out muff holes as well.

 

[pen]

Thanks guys.

Since these helicoils have ripped out, that's going to be a must.

Anyone switch to a stud instead of using bolts for this?

 

[DexterDay]

Hate to recommend another Forum. But there is a 340/345/350 expert on Another Site. He specializes in the 350, because it is the best homeowners platform out there. It is light weight, and a 346xp top end can bolted directly on for some serious gains.

Won't put it here.

PM if you want his "handle" on "AnotherSite".

 

[pen]

Thanks for the tip. No problems with recommending another site when it's in the context of aiding a help question. nepacrossroads.com is often mentioned as a recommended site for people coming here with certain questions.

I know we have a lot of expertise here as well which is why I started with the home crew.

Thanks again.

pen

 

[DexterDay]

Pretty sure i have broke some of the rules before and just didnt know if it would cross the line.

Lots of educated members here (also members there). But the one member is quite fluent in Husq 350

Cheers.

 

[firefighterjake]

I went the Loc=Tite route and so far so good.

 

[pen]

First time I had a bolt come loose during an inspection several years ago I pulled them both and applied the loctite. That bought me a year. Next time I found one loose I found a bit of the threads still stuck to the bolt and tried re-applying thinking it had burned out. That bought me another year. Last year they both came loose and helicoils went in and I welded the bolt head to keep them from coming loose, now I'm where I'm at.

As it figures, it came loose again Sat morning about 3/4 of the way through the first tank while a buddy and I were using a bulldozer to pull logs. Since my nice little saw went down, I had to use his husky 570 for limbing on steep grades and in tough brush (which is why the bulldozer was there as the farmall 450 can't get to this stuff). At the end of the day that 570 felt like a 5 gallon bucket filled with water to me.

I want this saw back in solid order as it's a beast for it's size. I really think if I go to larger helicoils, I need to find studs instead of bolts.

pen

 

[clemsonfor]

Maybe time for that 346 piston and jug!!

 

[MasterMech]

Just going to the larger diameter bolts should help. High heat loctite too. Are these mufflers sleeved inside like others that have long fasteners?

 

[bogydave]

Make sure to tighten them when the saw is hot.

My Husq. 359 book calls for :
" silencer, tighten bolts to a torque of 12–14 Nm"
Then
"Run the saw for at least 1 minute, then retighten
the silencer bolts to 8–10 Nm."

metric torque setting.

Newton meters .
10 Nm = 7.37 foot lbs
12 Nm = 8.85 foot lbs

 

[pen]

Just going to the larger diameter bolts should help. High heat loctite too. Are these mufflers sleeved inside like others that have long fasteners?

If memory serves, yes. Individual sleeves.

pen

 

[clemsonfor]

But sleeves where there ate recessed bolts or sleeves where the nut is on the farthest side out of muff?

 

[BrotherBart]

Don't know why anybody is bashful about saying http://www.arboristsite.com/firewood-heating-wood-burning-equipment/ . Chainsaw junkie heaven.

 

[DexterDay]

Here is a pretty good thread from a guy that knows quite a bit about this platform.
http://www.arboristsite.com/chainsaw/237587.htm

Very 1st post makes mention to use Loc tite. But post #11 further down also has a good cure for the loose muff bolt problem.

 

[WES999]

Can you use one of these?
http://www.mscdirect.com/product/36753069 key locking inserts
You will need enough material to to tap the cylinder M8.
We use these inserts frequently at work, they can be removed and replaced if needed.
The muffler screws on my 350 have never been a problem.

 

[pen]

Think I'm going to try the repair with the 288xp bolts.

Stopped into the local saw shop and spent some time with the husky 555 today. I'm kinda thinking the 350 needs a bigger brother

 

[firefighterjake]

Think I'm going to try the repair with the 288xp bolts.

Stopped into the local saw shop and spent some time with the husky 555 today. I'm kinda thinking the 350 needs a bigger brother

That's the saw I've been eye-balling as well for my next saw step up.

 

[MasterMech]

Think I'm going to try the repair with the 288xp bolts.

Stopped into the local saw shop and spent some time with the husky 555 today. I'm kinda thinking the 350 needs a bigger brother

You didn't get your CAD vaccine this year did you?

 

[pen]

In opening things up this morning the helicoils held just fine, it was the bolts themselves that stripped. I was expecting to find the helicoils pulled out. Sooo, going to try it again with new muffler bolts and see.

I'm thinking even though they were tight and welded, vibration killed the bolt's threads. Perhaps that muffler should have a support on it like that 288xp has.

Also, even with stock bolts I'm guessing the 350 will hold together a bit longer since it's going to change roles from primary to limb saw. Just called the shop back and bought the 555.

You didn't get your CAD vaccine this year did you?

I knew I shouldn't have skipped that spring check-up!

 

[PapaDave]

Just called the shop back and bought the 555

CAD at it's finest.

 

[Clarkbug]

What about using some threaded rod to make your own studs for the muffler? Put it in with red locktite and then just bolt on with your choice of fastener....

 

[pen]

What about using some threaded rod to make your own studs for the muffler? Put it in with red locktite and then just bolt on with your choice of fastener....

I had been thinking that too since so many exhausts use a stud and nut versus a bolt (automotive). But, I'm not an expert and I can't find anywhere that someone has tried it so I'm debating (not sure if I'm missing something and that's why others have not done this).

 

[HittinSteel]

In opening things up this morning the helicoils held just fine, it was the bolts themselves that stripped. I was expecting to find the helicoils pulled out. Sooo, going to try it again with new muffler bolts and see.

I'm thinking even though they were tight and welded, vibration killed the bolt's threads. Perhaps that muffler should have a support on it like that 288xp has.

Also, even with stock bolts I'm guessing the 350 will hold together a bit longer since it's going to change roles from primary to limb saw. Just called the shop back and bought the 555.



I knew I shouldn't have skipped that spring check-up!

I have read that a support was used on the later 350 mufflers. Let me do some more research and see what I can find.....maybe check with your dealer also.