Husqvarna 350 ignition issue

[gunns]

Woah! Thanks for really fast responses Wood Doctor, Bjorn T & Chevboy0167. I’ll have to check those out. Again thanks a bunch!!!

 

[Bjorn T]

https://www.partstree.com/models/346-xp-husqvarna-chainsaw-2007-08/cab-intake-air-filter-1/
Parts, 13,14,15 on the picture is for a 346, But it fits perfect. The metal Clamp is mutch better then the plastic Clamp.

 

[gunns]

Well, I checked the compression today and came up with 55 psi. Since this is the first time I used this compression gauge I took readings off of several other pieces of equipment. A Stihl shredder vac (75 psi), Toro string trimmer (75psi) and my big Echo backpack blower (100 psi). With these readings, I was thinking the gauge was reading extremely low as all of those units are working really well. However, doing the starter cord drop test (picking up the chainsaw by only using the starter cord)the saw cord slowly extended out so now I am thinking otherwise. looks like I have a choice of getting a new chainsaw or putting a new top end on my existing chainsaw. I checked the prices for the items needed for a top end rebuild on a website, and the total of parts came to over $200. At that point I decided to toss out the chainsaw and buy a new one. However, since that time I found top end rebuild kits on Amazon for $40-$90. So now I am having second thoughts about the possibilities of doing a top end job. I know some people will say the kits on Amazon are Chinese junk (not the sail boat, lol). But that’s exactly what Husqvarna uses. They have their parts made in China as well as other countries and then assemble them in Sweden. Husqvarna equipment are not Swedish made they are Swedish assembled units using Chinese parts. This revelation was disappointing as I’m a half-breed Swede. I understand Stihl does the same thing. So now I’ll probably do a top end rebuild.

 

[gunns]

Wood Doctor you say you’ve done top end rebuilds on the 350. Where did you get your parts? Did you use the kits on Amazon? If so which supplier and were you happy with the results?

 

[Bjorn T]

Hello. Original Husqvarna use Mahle cylinders, made in Germany.
But this Will work, https://www.hlsproparts.com/searchresults.asp?searching=Y&sort=13&cat=1782&show=30&page=5
make sure you dont have any airleaks.

 

[Wood Doctor]

Wood Doctor you say you’ve done top end rebuilds on the 350. Where did you get your parts? Did you use the kits on Amazon? If so which supplier and were you happy with the results?

Frankly, I have rarely seen a compression that low as you measured, but I doubt it's over 100 psi. I simply contacted a seller on e-bay. It's been a long time, so I imagine whomever I bought mine from is no longer in business. I was happy with the results, but while taking it apart. the plastic intake manifold clamp snapped. It's a poor design, and here is how I salvaged it:

That worked and the saw runs today. I used a 45 mm piston/cylinder kit that set me back less than $60 shipped. They are available today.

 

[gunns]

Thanks for the feed back guys!! Bjorn T I’ll be checking out your parts lead. Wood Doctor nice clamp fix - simple is always better! Mine has the metal clamp. Since my saw is a 350 I assume I’ll need the 45mm jug. Just a few more questions.

1. I assume there is a mark on the piston indicating its orientation. Does the mark face the exhaust or intake port?

2. Is the any requirement as to where the piston ring gap is pointed. I’ve worked on engines and sometimes you have no choice as they have placed a pin in the ring groove to keep it aligned.

3. Which side of the ring faces up Or does it not matter.

4. My 350 was purchased in 2007 and because I currently live in commifornia it’s an EPA1. Will it make any difference which kit I need? Will there be any difference in the head or piston?
Everything else seems rather straight forward. I’ll probably go ahead and replace the bellows since it’ll be easy to get to.

I did a Rube Goldberg hook up of the compression gauge to my air compressor and at 100psi on the air compressor the compression gauge read within 4 or 5 psi.

Again -thanks a lot! You guys have been very helpful!!!!

 

[J D]

1. Arrow on piston points to exhaust
2, 3. Ring is located by a pin in the ring groove which determines position & orientation.
4. Any kit will work. The ideal would be a genuine 346xp ne top end. Aftermarket ones (especially the cheap amazon/ebay) are hit & miss. Main difference on your epa variant is the muffler. Be advisable to replace that with an empty one at the same time.

First thing I'd be doing is pulling the exhaust on your saw to view the piston. The "drop test" can be deceiving as a scored piston with a stuck ring can generate enough friction to give the illusion of compression.

Your compression tester likely isn't designed for small engines & lacks a schrader valve, or you're not pulling until compression stops rising.
From the numbers you gave I would suspect your saw has a true compression of 100-110psi which would explain your getting nothing more than the occasional "pop"

 

[Bjorn T]

Thanks for the feed back guys!! Bjorn T I’ll be checking out your parts lead. Wood Doctor nice clamp fix - simple is always better! Mine has the metal clamp. Since my saw is a 350 I assume I’ll need the 45mm jug. Just a few more questions.

1. I assume there is a mark on the piston indicating its orientation. Does the mark face the exhaust or intake port?

2. Is the any requirement as to where the piston ring gap is pointed. I’ve worked on engines and sometimes you have no choice as they have placed a pin in the ring groove to keep it aligned.

3. Which side of the ring faces up Or does it not matter.

4. My 350 was purchased in 2007 and because I currently live in commifornia it’s an EPA1. Will it make any difference which kit I need? Will there be any difference in the head or piston?
Everything else seems rather straight forward. I’ll probably go ahead and replace the bellows since it’ll be easy to get to.

I did a Rube Goldberg hook up of the compression gauge to my air compressor and at 100psi on the air compressor the compression gauge read within 4 or 5 psi.

Again -thanks a lot! You guys have been very helpful!!!!

Hello, a 346 cylinder Will fit, and give you more power. Better construction on the cylinder.

 

[Chevboy0167]

A 346 top end will bolt on and fit, but some modifications have to be done if you use a cast transfer port cylinder. I know this cuz I did it last summer to 3 saws. Now, if you use the cylinder with the bolted-on transfer port covers, then maybe 1 less mod, to saw body plastic.

Gotta grind the plastic ribs down flat on the full cast cylinder.



Also, may have to grind the transfer port face and sand down the back of the flywheel so the 2 don't hit.




And then you gotta drill a hole through the cylinder bore where the impulse is. I also use my pencil die grinder to create a trench just like factory 350 cylinder has for better volume. The stock 350 does not have the hole in the crankcase like the other saws to pull vacuum as it is plastic and has an aluminum riser. Finally, block off the hole in the cylinder base as to seal up a possible leak area. I use Ultra Copper or Dirko with a drill bit slid in to keep the sealant from clogging up the new hole you drill and let it dry for a day or 3




Yes, if a guy was good and spent some time, you can drill the riser in 2 places to create the crankcase impulse channel.



Stock 350 impulse channel....

 

[gunns]

Concerning my compression tester's accuracy I hooked it up to my air compressor and set its gauge to various settings 50, 75, 100, and 125 psi. The compression tester always read within in a few psi of those settings. So it ok.

I'm starting my top-end rebuild today. After watching several You-Boob videos I'll be doing a complete tear down so I can make sure the bearing cap is properly sealed to the chassis. I've heard that Loctite 518 Is used on the cylinder gasket but videos only being used on the bottom of the gasket not the top. I would assume it'd be used on both sides. Did they use it on the bottom of the gasket just to hold it in place for assembly? They also mentioned using Threebond 1194 to seal the bearing cap to the chassis. If I can't find those sealants in my area are there other equally good substitutes?

Now the big question. SQUISH? Are they talkin about using or not using the cylinder gasket and the milling of the top of the bearing cap to adjust the piston travel for higher compression and safety from topping out against the head?

As always all of you contributors have been great and it has been greatly appreciated!!!

 

[Chevboy0167]

Permatex Mototseal for the sealant. Use it to seal the aluminum riser to the plastic lower crankcase. That riser has to go a certain way so the cylinder sits correctly! Do a dry test fit first, then add the Motoseal to the riser and around the outside of the rubber crank seals. Thin finger wipe layer is best.

After crank and riser is all bolted up, leave out the base gasket, put piston on rod without the ring! Slide the cylinder over piston, install 2 cylinder bolts opposite of each other and tighten down. Watch a few YouTube videos on how to check squish as it is too much to type out


Once you find the squish you like, then pull the cylinder off and install the piston ring

Squish at .020", (thousands of an inch), or more, you leave out the base gasket and coat the riser with a film of Mototseal. Anything less than .020", then use the base gasket. When using a gasket, you really don't have to use sealant, but can if you like. Both sides won't hurt. Just make it a thin layer.

 

[Bob Hedgecutter]

Concerning my compression tester's accuracy I hooked it up to my air compressor and set its gauge to various settings 50, 75, 100, and 125 psi. The compression tester always read within in a few psi of those settings. So it ok.

Nobody is doubting the compression tester you bought has the ability to read pressure as supplied from the like of a multi cylinder internal combustion engine- or an air compressor.
What we are doubting is the particular gauge you bought having the ability to read small volume low pressure combustion from a small single cylinder engine.

 

[gunns]

Thanks Chevboy0167! Makes sense. I’ll also be changing out the crank assy as there is some, not a lot but some, play in the crank end of the rod. Not the rod sliding laterally on the rod journal but movement when the rod’s crank end is held stationary and the piston end is pushed left to right. The crank seals and bearings will also be replaced. It’s all torn down anyway so DIRDIO (do it right do it once).

In determining which model 350 to select parts for I frequently see 2003-1 & 2004-3 as well as other year designations and never sure which to choose. I purchased mine new in 2007. Can you explain what it all means? I’ll check out the Squish vids on You-Boob. Thanks again!!

 

[gunns]

Spent a couple hours and stops at five different businesses trying to find Threebond 1194 and Loctite 518. Finally found the Permatex Motoseal for sealing the case/riser that Chevboy0167 suggested as a substitute for Threebond and the Loctite 518 for the cylinder/riser sealing. Bearings, seals and crank assy ordered this morning from HLsupply. Everything is all cleaned up now. Just waiting for parts.

Again I’m impressed with the super quick and no nonsense no B/S approach of you members. It’s refreshing using a forum where every other poster isn’t a keyboard warrior. Thanks yet again guys! Now it’s just wait tick tock tick tock ti……………

 

[Wood Doctor]

While you are at it, you may want to consider a 350 muffler mod using a 353 support as shown here:

This strengthens the 350 muffler support very well and without it, the engine can easily vibrate the two bolts loose.

 

[gunns]

I was considering that. Saw it in a few of the YouBoob videos. Do you know what the 2003-01, 2004-03 etc. references?

 

[J D]

Spent a couple hours and stops at five different businesses trying to find Threebond 1194 and Loctite 518. Finally found the Permatex Motoseal for sealing the case/riser that Chevboy0167 suggested as a substitute for Threebond and the Loctite 518 for the cylinder/riser sealing. Bearings, seals and crank assy ordered this morning from HLsupply. Everything is all cleaned up now. Just waiting for parts.

Again I’m impressed with the super quick and no nonsense no B/S approach of you members. It’s refreshing using a forum where every other poster isn’t a keyboard warrior. Thanks yet again guys! Now it’s just wait tick tock tick tock ti……………

If you still have it apart it doesn't hurt to run the riser block over some 400+ grit sand paper on something very flat like a piece of glass... a lot of the blocks aren't as even as they should be

 

[HumBurner]

I was considering that. Saw it in a few of the YouBoob videos. Do you know what the 2003-01, 2004-03 etc. references?

Those are the dates of the IPL's. When enough parts change or are updated, the manufacturer releases a new Parts List.

 

[gunns]

Thanks JD. I saw that in a video and had that in mind but I’ve got to get all the factory sealant off first. What works bet? Possibly something that dissolves/loosens it’s but won’t harm the chassis.