My Husky 346xp has a 41.7mm piston....??

[Heteractis]

From the pdf, it is the small rubber cylinder at the bottom of the intake below that is split around the join, item 13 on the carb ass drawing. I have the plastic clamp so this could be a leak point that has gone unnoticed.

 

Also I notice I don't have the air filter clip, item 5, so the air filter is very loose.

 

I will check the impulse line tomorrow. My next question is where do I get the parts from? Most places say out of stock or come from Hong Kong or the US?

 

Thanks

[SawTroll]

From the pdf, it is the small rubber cylinder at the bottom of the intake below that is split around the join, item 13 on the carb ass drawing. I have the plastic clamp so this could be a leak point that has gone unnoticed.

 

Also I notice I don't have the air filter clip, item 5, so the air filter is very loose.

 

I will check the impulse line tomorrow. My next question is where do I get the parts from? Most places say out of stock or come from Hong Kong or the US?

 

Thanks

Try any Husky dealer, by all means avoid any Asian aftermarket parts.

 

 

Also, Husky parts generally are the easiest of all to buy on the Internet, but I have no knowledge of the UK situation?

 

The early 346xp saws didn't have the air filter with the clip, but rather a twist-on one.

My 2003 353 has that variant, and it never caused any issues. Remember to order the right one, if you are replacing your filter, or getting spares. Avoid the black-bodied "winter" filters.

 

 

http://www.barrettsmallengine.com/partslist/husqvarna346xp-2001-06.pdf

 

http://www.barrettsmallengine.com/partslist/husqvarna346xp-1999-03.PDF

Edited July 6, 2015 by SawTroll

[Heteractis]

Many thanks for everyone's help so far but sadly the saw is still not very well...

 

So I replace the piston and ring, the carb bellows, the flywheel (that I broke...) and put a new section of hose on the impulse line just encase. I couldn't find the full assy of the carb bellows with the new metal clamp but the one I have seemed pretty tight so carried on as it is. Gave it a clean and set the carb to 1 turn out on both L and H. Got it started no problems, compression was excellent (didn't measure it but much harder to pull over). Tuned the carb as per the manual and various posts, all went well. Saw starting on first pull every time from cold or hot. Used it at the weekend for the first time over the weekend to level off some stumps, got through 2 stumps and it needed a refuel. Put new mix in it (50:1 using mixing bottle) and it wouldn't start. Took spark plug off and it looked wet so assumed it was flooded. Took spark plug off, turned it upside down and gave it 30 or so pulls and left it over the weekend to 'dry out'. Tried it today and still wouldn't start so thought I would take it apart to dry it off, looked through the exhaust port and the piston and ring are fried again, worse than before. Strangely it feels like the compression is still good but the ring is stuck in the piston so it is knackered.

 

So tempted to sell the bloody thing and let someone else faf with it! I only need it for some logging for firewood!

 

Anyway, I am assuming there must be an air leak that I haven't found. Could someone point me in the direction of a guide for leak testing? Even if I sell it, I would rather sell a working saw than a crap one!

 

Thanks,

[spudulike]

Many thanks for everyone's help so far but sadly the saw is still not very well...

 

So I replace the piston and ring, the carb bellows, the flywheel (that I broke...) and put a new section of hose on the impulse line just encase. I couldn't find the full assy of the carb bellows with the new metal clamp but the one I have seemed pretty tight so carried on as it is. Gave it a clean and set the carb to 1 turn out on both L and H. Got it started no problems, compression was excellent (didn't measure it but much harder to pull over). Tuned the carb as per the manual and various posts, all went well. Saw starting on first pull every time from cold or hot. Used it at the weekend for the first time over the weekend to level off some stumps, got through 2 stumps and it needed a refuel. Put new mix in it (50:1 using mixing bottle) and it wouldn't start. Took spark plug off and it looked wet so assumed it was flooded. Took spark plug off, turned it upside down and gave it 30 or so pulls and left it over the weekend to 'dry out'. Tried it today and still wouldn't start so thought I would take it apart to dry it off, looked through the exhaust port and the piston and ring are fried again, worse than before. Strangely it feels like the compression is still good but the ring is stuck in the piston so it is knackered.

 

So tempted to sell the bloody thing and let someone else faf with it! I only need it for some logging for firewood!

 

Anyway, I am assuming there must be an air leak that I haven't found. Could someone point me in the direction of a guide for leak testing? Even if I sell it, I would rather sell a working saw than a crap one!

 

Thanks,

 

These saws are notoriously bad for leaking around the inlet manifold, the older the manifold, the worse they are. I have also had them leak and then just rotating the manifold round 0.5mm seals it up for good. The small crack around the impulse moulding on the manifold is also pretty common as is not getting the alignment right and squashing the thing on reassembly!

 

I know this from experience and pressure/Vac check all saws on reassembly so the top end isn't taken out like you have just done. The clutch side seal is also prone to failure and can leak.

 

Pressure & Vac testing, you really need the right kit and that will cost £50-75, it may be better to hand it to someone with the right kit and get them to check it over. Hopefully the bore is OK and with a new piston and a little TLC......

 

Each saw has it's own set of strengths, weaknesses and little things that they need to get them 100%, the 346XP was a fine replacement for the 254XP and is a great performer but like most saws that seize, a rout cause has to be found before running up again!

 

Was the fuel line OK, this can cause this type of issue?

[Heteractis]

I did wonder about re building it without some sort of pressure test but assumed (hoped..!!) that the broken bits I had found would sort it.

 

I am not sure if it is worth investing any more money in this one or sell as is and get a cheap Chinese one for what I need to do. The wife and I are building a house and I only have the chainsaw to cut up all the logs we have after the tree surgeon took most of the trees down for us. I do have an awful lot of wood to get through mind, approx. 30 Tons at last count!

 

Looking at it now, the first piston is probably salvageable so maybe just a new ring would do once I find the root cause. I am wondering about the fuel mix too as I used the same tank of fuel for both knackered pistons so it may well be there wasn't enough oil in the mix - a friend of mine did most of the mixing so I couldn't be sure it wasn't a bad mix.

 

I didn't replace the fuel line (the one from the tank into the carb) so I may as well change this as I have enough fuel line left over. The impulse line looked fine but I changed it anyway. I maybe able to put the kit together for the test as we have a full mechanics workshop at work, presumably I remove the air filter and plug the carb inlet and plug the exhaust outlet and pressurise through the spark plug hole? Watch for the pressure to drop and check for bubbles with some soapy water?

 

Maybe I should just cut my loses and give it to you to fix Spud..!!

 

Thanks,

[spudulike]

Yes, the pressure check is about pumping up the crankcase up to around 10psi and then watching the gauge for any drop but guess you could do without the gauge and use soapy water around all the joints and crank seals - easier with a gauge but possible without.

 

You block the impulse, the inlet manifold and exhaust and input air in through the plug hole.

 

I can look at it if you like - PM me if needed.

[adw]

Cant believe you ran the same tank of fuel from the first seizure, the fuel mix may have been the route cause all along, do you have any idea what oil he mixed with the fuel?

[spudulike]

Cant believe you ran the same tank of fuel from the first seizure, the fuel mix may have been the route cause all along, do you have any idea what oil he mixed with the fuel?

 

Or the age of the mix, the 346XP does rev pretty high and the oil in the fuel mix degrades over time.....damn, someone will mention Aspen soon:001_rolleyes: If the mix was over a month old and possibly a bit light on oil.....it could have been enough.

[SawTroll]

Or the age of the mix, the 346XP does rev pretty high and the oil in the fuel mix degrades over time.....damn, someone will mention Aspen soon If the mix was over a month old and possibly a bit light on oil.....it could have been enough.

 

 

Aspen!

[Heteractis]

The fuel was maybe a week old from mixing at most but no, I cant guarantee the mix. A friend of mine has been helping me with the chainsaw work as he is a former aborist so I would like to think he would get it right but you never know! We have been using a 1 litre mixing bottle with lines to identify the correct ratio, 20:1,40:1,50:1 etc so you fill with petrol up to the 1 litre line then add oil up to the 50:1 line. We have been using this method for other chainsaws and strimmers etc. with no issue so far.

 

Yes I should have changed the fuel but to be honest I hadn't even considered it a factor until now. I was speaking to our mechanic at work and he said there are only two ways to ruin a 2 stroke, not enough oil or revving too high so after he said that I thought about the fuel mix and the carb tuning. I suppose it could have been the carb tuning that did it but that seemed pretty good, finally settings were L = 3/4 turn anti clockwise, H - 1 1/2 turns anti clockwise. Idle was good and starting first pull. 4 stroking at WOT and cleaning in the cut with a slight 4 stroking.

 

So the pressure test, do I remove the carb for this but keep the inlet bellows with impulse line attached and block that off? That would make sense.